Class: Magick::Image

Inherits:
Object
  • Object
show all
Includes:
Comparable
Defined in:
lib/RMagick.rb,
ext/RMagick/rmmain.c

Overview

Ruby-level Magick::Image methods

Defined Under Namespace

Classes: DrawOptions, Info, PolaroidOptions, View

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(*args) ⇒ Object

Method: Image#initialize(cols,rows,) Purpose: initialize a new Image object

If the fill argument is omitted, fill with background color

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# File 'ext/RMagick/rmimage.c', line 6888

VALUE
Image_initialize(int argc, VALUE *argv, VALUE self)
{
    volatile VALUE fill = 0;
    Info *info;
    volatile VALUE info_obj;
    Image *image;
    unsigned long cols, rows;

    switch (argc)
    {
        case 3:
            fill = argv[2];
        case 2:
            rows = NUM2ULONG(argv[1]);
            cols = NUM2ULONG(argv[0]);
            break;
        default:
            rb_raise(rb_eArgError, "wrong number of arguments (%d for 2 or 3)", argc);
            break;
    }

    // Create a new Info object to use when creating this image.
    info_obj = rm_info_new();
    Data_Get_Struct(info_obj, Info, info);

    image = AcquireImage(info);
    if (!image)
    {
        rb_raise(rb_eNoMemError, "not enough memory to continue");
    }

    rm_set_user_artifact(image, info);

    // NOW store a real image in the image object.
    UPDATE_DATA_PTR(self, image);

    SetImageExtent(image, cols, rows);

    // If the caller did not supply a fill argument, call SetImageBackgroundColor
    // to fill the image using the background color. The background color can
    // be set by specifying it when creating the Info parm block.
    if (!fill)
    {
        (void) SetImageBackgroundColor(image);
    }
    // fillobj.fill(self)
    else
    {
        (void) rb_funcall(fill, rm_ID_fill, 1, self);
    }

    return self;
}

Class Method Details

._load(str) ⇒ Object

Method: Image._load Purpose: implement marshalling Notes: calls BlobToImage - see Image#_dump


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# File 'ext/RMagick/rmimage.c', line 6006

VALUE
Image__load(VALUE class, VALUE str)
{
    Image *image;
    ImageInfo *info;
    DumpedImage mi;
    ExceptionInfo exception;
    char *blob;
    long length;

    class = class;  // Suppress "never referenced" message from icc

    info = CloneImageInfo(NULL);

    blob = rm_str2cstr(str, &length);

    // Must be as least as big as the 1st 4 fields in DumpedImage
    if (length <= (long)(sizeof(DumpedImage)-MaxTextExtent))
    {
        rb_raise(rb_eTypeError, "image is invalid or corrupted (too short)");
    }

    // Retrieve & validate the image format from the header portion
    mi.id = ((DumpedImage *)blob)->id;
    if (mi.id != DUMPED_IMAGE_ID)
    {
        rb_raise(rb_eTypeError, "image is invalid or corrupted (invalid header)");
    }

    mi.mj = ((DumpedImage *)blob)->mj;
    mi.mi = ((DumpedImage *)blob)->mi;
    if (   mi.mj != DUMPED_IMAGE_MAJOR_VERS
           || mi.mi > DUMPED_IMAGE_MINOR_VERS)
    {
        rb_raise(rb_eTypeError, "incompatible image format (can't be read)\n"
                 "\tformat version %d.%d required; %d.%d given"
                 , DUMPED_IMAGE_MAJOR_VERS, DUMPED_IMAGE_MINOR_VERS
                 , mi.mj, mi.mi);
    }

    mi.len = ((DumpedImage *)blob)->len;

    // Must be bigger than the header
    if (length <= (long)(mi.len+sizeof(DumpedImage)-MaxTextExtent))
    {
        rb_raise(rb_eTypeError, "image is invalid or corrupted (too short)");
    }

    memcpy(info->magick, ((DumpedImage *)blob)->magick, mi.len);
    info->magick[mi.len] = '\0';

    GetExceptionInfo(&exception);

    blob += offsetof(DumpedImage,magick) + mi.len;
    length -= offsetof(DumpedImage,magick) + mi.len;
    image = BlobToImage(info, blob, (size_t) length, &exception);
    (void) DestroyImageInfo(info);

    rm_check_exception(&exception, image, DestroyOnError);

    (void) DestroyExceptionInfo(&exception);

    rm_ensure_result(image);

    return rm_image_new(image);
}

.capture(*args) ⇒ Object

Method: Image.capture(silent=false,

frame=false,
descend=false,
screen=false,
borders=false) { optional parms }

Purpose: do a screen capture


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# File 'ext/RMagick/rmimage.c', line 1454

VALUE
Image_capture(int argc, VALUE *argv, VALUE self)
{
    Image *image;
    ImageInfo *image_info;
    volatile VALUE info_obj;
    XImportInfo ximage_info;

    self = self;  // Suppress "never referenced" message from icc

    XGetImportInfo(&ximage_info);
    switch (argc)
    {
        case 5:
            ximage_info.borders = (MagickBooleanType)RTEST(argv[4]);
        case 4:
            ximage_info.screen  = (MagickBooleanType)RTEST(argv[3]);
        case 3:
            ximage_info.descend = (MagickBooleanType)RTEST(argv[2]);
        case 2:
            ximage_info.frame   = (MagickBooleanType)RTEST(argv[1]);
        case 1:
            ximage_info.silent  = (MagickBooleanType)RTEST(argv[0]);
        case 0:
            break;
        default:
            rb_raise(rb_eArgError, "wrong number of arguments (%d for 0 to 5)", argc);
            break;
    }

    // Get optional parms.
    // Set info->filename = "root", window ID number or window name,
    //  or nothing to do an interactive capture
    // Set info->server_name to the server name
    // Also info->colorspace, depth, dither, interlace, type
    info_obj = rm_info_new();
    Data_Get_Struct(info_obj, Info, image_info);

    // If an error occurs, IM will call our error handler and we raise an exception.
    image = XImportImage(image_info, &ximage_info);
    rm_check_image_exception(image, DestroyOnError);
    rm_ensure_result(image);

    rm_set_user_artifact(image, image_info);

    return rm_image_new(image);
}

.combineObject

.constitute(width_arg, height_arg, map_arg, pixels_arg) ⇒ Object

Method: Image.constitute(width, height, map, pixels) Purpose: Creates an Image from the supplied pixel data. The

pixel data must be in scanline order, top-to-bottom.
The pixel data is an array of either all Fixed or all Float
elements. If Fixed, the elements must be in the range
[0..QuantumRange]. If Float, the elements must be normalized [0..1].
The "map" argument reflects the expected ordering of the pixel
array. It can be any combination or order of R = red, G = green,
B = blue, A = alpha, C = cyan, Y = yellow, M = magenta,
K = black, or I = intensity (for grayscale).

The pixel array must have width X height X strlen(map) elements.

Raises: ArgumentError, TypeError


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# File 'ext/RMagick/rmimage.c', line 2808

VALUE
Image_constitute(VALUE class, VALUE width_arg, VALUE height_arg
                 , VALUE map_arg, VALUE pixels_arg)
{
    Image *image;
    ExceptionInfo exception;
    volatile VALUE pixel, pixel0;
    unsigned long width, height;
    long x, npixels;
    char *map;
    long map_l;
    volatile union
    {
        double *f;
        Quantum *i;
        void *v;
    } pixels;
    volatile VALUE pixel_class;
    StorageType stg_type;

    class = class;  // Suppress "never referenced" message from icc

            // rb_Array converts objects that are not Arrays to Arrays if possible,
            // and raises TypeError if it can't.
            pixels_arg = rb_Array(pixels_arg);

    width = NUM2ULONG(width_arg);
    height = NUM2ULONG(height_arg);

    if (width == 0 || height == 0)
    {
        rb_raise(rb_eArgError, "width and height must be non-zero");
    }

    map = rm_str2cstr(map_arg, &map_l);

    npixels = (long)(width * height * map_l);
    if (RARRAY_LEN(pixels_arg) != npixels)
    {
        rb_raise(rb_eArgError, "wrong number of array elements (%ld for %ld)"
                 , RARRAY_LEN(pixels_arg), npixels);
    }

    // Inspect the first element in the pixels array to determine the expected
    // type of all the elements. Allocate the pixel buffer.
    pixel0 = rb_ary_entry(pixels_arg, 0);
    if (rb_obj_is_kind_of(pixel0, rb_cFloat) == Qtrue)
    {
        pixels.f = ALLOC_N(double, npixels);
        stg_type = DoublePixel;
        pixel_class = rb_cFloat;
    }
    else if (rb_obj_is_kind_of(pixel0, rb_cInteger) == Qtrue)
    {
        pixels.i = ALLOC_N(Quantum, npixels);
        stg_type = QuantumPixel;
        pixel_class = rb_cInteger;
    }
    else
    {
        rb_raise(rb_eTypeError, "element 0 in pixel array is %s, must be numeric"
                 , rb_class2name(CLASS_OF(pixel0)));
    }



    // Convert the array elements to the appropriate C type, store in pixel
    // buffer.
    for (x = 0; x < npixels; x++)
    {
        pixel = rb_ary_entry(pixels_arg, x);
        if (rb_obj_is_kind_of(pixel, pixel_class) != Qtrue)
        {
            rb_raise(rb_eTypeError, "element %ld in pixel array is %s, expected %s"
                     , x, rb_class2name(CLASS_OF(pixel)),rb_class2name(CLASS_OF(pixel0)));
        }
        if (pixel_class == rb_cFloat)
        {
            pixels.f[x] = (float) NUM2DBL(pixel);
            if (pixels.f[x] < 0.0 || pixels.f[x] > 1.0)
            {
                rb_raise(rb_eArgError, "element %ld is out of range [0..1]: %f", x, pixels.f[x]);
            }
        }
        else
        {
            pixels.i[x] = NUM2QUANTUM(pixel);
        }
    }

    GetExceptionInfo(&exception);

    // This is based on ConstituteImage in IM 5.5.7
    image = AcquireImage(NULL);
    if (!image)
    {
        rb_raise(rb_eNoMemError, "not enough memory to continue.");
    }

    SetImageExtent(image, width, height);
    rm_check_image_exception(image, DestroyOnError);

    (void) SetImageBackgroundColor(image);
    rm_check_image_exception(image, DestroyOnError);

    (void) ImportImagePixels(image, 0, 0, width, height, map, stg_type, (const void *)pixels.v);
    xfree(pixels.v);
    rm_check_image_exception(image, DestroyOnError);

    (void) DestroyExceptionInfo(&exception);
    DestroyConstitute();

    return rm_image_new(image);
}

.from_blob(blob_arg) ⇒ Object

Method: Image.from_blob(blob) <{ parm block }> Purpose: Call BlobToImage Notes: The blob is a String


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# File 'ext/RMagick/rmimage.c', line 4942

VALUE
Image_from_blob(VALUE class, VALUE blob_arg)
{
    Image *images;
    Info *info;
    volatile VALUE info_obj;
    ExceptionInfo exception;
    void *blob;
    long length;

    class = class;          // defeat gcc message
            blob_arg = blob_arg;    // defeat gcc message

    blob = (void *) rm_str2cstr(blob_arg, &length);

    // Get a new Info object - run the parm block if supplied
    info_obj = rm_info_new();
    Data_Get_Struct(info_obj, Info, info);

    GetExceptionInfo(&exception);
    images = BlobToImage(info,  blob, (size_t)length, &exception);
    rm_check_exception(&exception, images, DestroyOnError);

    (void) DestroyExceptionInfo(&exception);

    rm_ensure_result(images);
    rm_set_user_artifact(images, info);

    return array_from_images(images);
}

.ping(file_arg) ⇒ Object

Method: Image.ping(file) Purpose: Call ImagePing Returns: Same as Image.read, except that PingImage does not

return the pixel data.

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# File 'ext/RMagick/rmimage.c', line 7398

VALUE
Image_ping(VALUE class, VALUE file_arg)
{
    return rd_image(class, file_arg, PingImage);
}

.read(file_arg) ⇒ Object

Method: Image.read(file) Purpose: Call ReadImage Returns: An array of 1 or more new image objects.


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# File 'ext/RMagick/rmimage.c', line 8089

VALUE
Image_read(VALUE class, VALUE file_arg)
{
    return rd_image(class, file_arg, ReadImage);
}

.read_inline(content) ⇒ Object

Method: Image.read_inline(content) Purpose: Read a Base64-encoded image Returns: an array of new images Notes: this is similar to, but not the same as ReadInlineImage.

ReadInlineImage requires a comma preceeding the image
data. This method allows but does not require a comma.

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# File 'ext/RMagick/rmimage.c', line 8210

VALUE
Image_read_inline(VALUE self, VALUE content)
{
    volatile VALUE info_obj;
    Image *images;
    ImageInfo *info;
    char *image_data;
    long x, image_data_l;
    unsigned char *blob;
    size_t blob_l;
    ExceptionInfo exception;

    self = self;    // defeat gcc message

    image_data = rm_str2cstr(content, &image_data_l);

    // Search for a comma. If found, we'll set the start of the
    // image data just following the comma. Otherwise we'll assume
    // the image data starts with the first byte.
    for (x = 0; x < image_data_l; x++)
    {
        if (image_data[x] == ',')
        {
            break;
        }
    }
    if (x < image_data_l)
    {
        image_data += x + 1;
    }

    blob = Base64Decode(image_data, &blob_l);
    if (blob_l == 0)
    {
        rb_raise(rb_eArgError, "can't decode image");
    }

    GetExceptionInfo(&exception);

    // Create a new Info structure for this read. About the
    // only useful attribute that can be set is `format'.
    info_obj = rm_info_new();
    Data_Get_Struct(info_obj, Info, info);

    images = BlobToImage(info, blob, blob_l, &exception);
    magick_free((void *)blob);

    rm_check_exception(&exception, images, DestroyOnError);

    (void) DestroyExceptionInfo(&exception);
    rm_set_user_artifact(images, info);

    return array_from_images(images);
}

Instance Method Details

#<=>(other) ⇒ Object

Method: Image#spaceship (a <=> b) Purpose: compare two images Returns: -1, 0, 1


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# File 'ext/RMagick/rmimage.c', line 9284

VALUE
Image_spaceship(VALUE self, VALUE other)
{
    Image *imageA, *imageB;
    const char *sigA, *sigB;
    int res;

    imageA = rm_check_destroyed(self);

    // If the other object isn't a Image object, then they can't be equal.
    if (!rb_obj_is_kind_of(other, Class_Image))
    {
        return Qnil;
    }

    imageB = rm_check_destroyed(other);

    (void) SignatureImage(imageA);
    (void) SignatureImage(imageB);
    sigA = rm_get_property(imageA, "signature");
    sigB = rm_get_property(imageB, "signature");
    if (!sigA || !sigB)
    {
        rb_raise(Class_ImageMagickError, "can't get image signature");
    }

    res = memcmp(sigA, sigB, 64);
    res = res > 0 ? 1 : (res < 0 ? -1 :  0);    // reduce to 1, -1, 0

    return INT2FIX(res);
}

#[](key_arg) ⇒ Object

Method: Image#

Image#[:key]

Purpose: Return the image property associated with “key” Returns: property value or nil if key doesn't exist Notes: Use Image#[]= (aset) to establish more properties

or change the value of an existing property.

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# File 'ext/RMagick/rmimage.c', line 574

VALUE
Image_aref(VALUE self, VALUE key_arg)
{
    Image *image;
    const char *key;
    const char *attr;

    image = rm_check_destroyed(self);

    switch (TYPE(key_arg))
    {
        case T_NIL:
            return Qnil;

        case T_SYMBOL:
            key = rb_id2name((ID)SYM2ID(key_arg));
            break;

        default:
            key = StringValuePtr(key_arg);
            if (*key == '\0')
            {
                return Qnil;
            }
            break;
    }


    if (rm_strcasecmp(key, "EXIF:*") == 0)
    {
        return rm_exif_by_entry(image);
    }
    else if (rm_strcasecmp(key, "EXIF:!") == 0)
    {
        return rm_exif_by_number(image);
    }

    attr = rm_get_property(image, key);
    return attr ? rb_str_new2(attr) : Qnil;
}

#[]=(key_arg, attr_arg) ⇒ Object

Method: Image# = attr

Image#[:key] = attr

Purpose: Update or add image attribute “key” Returns: self Notes: Specify attr=nil to remove the key from the list.

SetImageProperty normally APPENDS the new value
to any existing value. Since this usage is tremendously
counter-intuitive, this function always deletes the
existing value before setting the new value.

There's no use checking the return value since
SetImageProperty returns "False" for many reasons,
some legitimate.

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# File 'ext/RMagick/rmimage.c', line 631

VALUE
Image_aset(VALUE self, VALUE key_arg, VALUE attr_arg)
{
    Image *image;
    const char *key;
    char *attr;
    unsigned int okay;

    image = rm_check_frozen(self);

    attr = attr_arg == Qnil ? NULL : StringValuePtr(attr_arg);

    switch (TYPE(key_arg))
    {
        case T_NIL:
            return self;

        case T_SYMBOL:
            key = rb_id2name((ID)SYM2ID(key_arg));
            break;

        default:
            key = StringValuePtr(key_arg);
            if (*key == '\0')
            {
                return self;
            }
            break;
    }


    // Delete existing value. SetImageProperty returns False if
    // the attribute doesn't exist - we don't care.
    (void) rm_set_property(image, key, NULL);
    // Set new value
    if (attr)
    {
        okay = rm_set_property(image, key, attr);
        if (!okay)
        {
            rb_warning("SetImageProperty failed (probably out of memory)");
        }
    }
    return self;
}

#_dump(depth) ⇒ Object

Method: Image#_dump(aDepth) Purpose: implement marshalling Returns: a string representing the dumped image Notes: uses ImageToBlob - use the MIFF format

in the blob since it's the most general

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# File 'ext/RMagick/rmimage.c', line 3940

VALUE
Image__dump(VALUE self, VALUE depth)
{
    Image *image;
    ImageInfo *info;
    void *blob;
    size_t length;
    DumpedImage mi;
    volatile VALUE str;
    ExceptionInfo exception;

    depth = depth;  // Suppress "never referenced" message from icc

    image = rm_check_destroyed(self);

    info = CloneImageInfo(NULL);
    if (!info)
    {
        rb_raise(rb_eNoMemError, "not enough memory to continue");
    }
    strcpy(info->magick, image->magick);

    GetExceptionInfo(&exception);
    blob = ImageToBlob(info, image, &length, &exception);

    // Free ImageInfo first - error handling may raise an exception
    (void) DestroyImageInfo(info);

    CHECK_EXCEPTION()

    (void) DestroyExceptionInfo(&exception);

    if (!blob)
    {
        rb_raise(rb_eNoMemError, "not enough memory to continue");
    }

    // Create a header for the blob: ID and version
    // numbers, followed by the length of the magick
    // string stored as a byte, followed by the
    // magick string itself.
    mi.id = DUMPED_IMAGE_ID;
    mi.mj = DUMPED_IMAGE_MAJOR_VERS;
    mi.mi = DUMPED_IMAGE_MINOR_VERS;
    strcpy(mi.magick, image->magick);
    mi.len = (unsigned char) min((size_t)UCHAR_MAX, strlen(mi.magick));

    // Concatenate the blob onto the header & return the result
    str = rb_str_new((char *)&mi, (long)(mi.len+offsetof(DumpedImage,magick)));
    str = rb_str_buf_cat(str, (char *)blob, (long)length);
    magick_free((void*)blob);
    return str;
}

#adaptive_blur(*args) ⇒ Object

Method: Image#adaptive_blur(radius=0.0, sigma=1.0) Purpose: call AdaptiveBlurImage


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# File 'ext/RMagick/rmimage.c', line 125

VALUE
Image_adaptive_blur(int argc, VALUE *argv, VALUE self)
{
    return adaptive_method(argc, argv, self, AdaptiveBlurImage);
}

#adaptive_blur_channel(*args) ⇒ Object

Method: Image#adaptive_blur_channel(radius=0.0, sigma=1.0[ , channel…]) Purpose: call AdaptiveBlurImageChannel


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# File 'ext/RMagick/rmimage.c', line 137

VALUE
Image_adaptive_blur_channel(int argc, VALUE *argv, VALUE self)
{
    return adaptive_channel_method(argc, argv, self, AdaptiveBlurImageChannel);
}

#adaptive_resize(*args) ⇒ Object

Method: Image#adaptive_resize(scale_val)

Image#adaptive_resize(cols, rows)

Purpose: Call AdaptiveResizeImage


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# File 'ext/RMagick/rmimage.c', line 149

VALUE
Image_adaptive_resize(int argc, VALUE *argv, VALUE self)
{
    Image *image, *new_image;
    unsigned long rows, columns;
    double scale_val, drows, dcols;
    ExceptionInfo exception;

    image = rm_check_destroyed(self);

    switch (argc)
    {
        case 2:
            rows = NUM2ULONG(argv[1]);
            columns = NUM2ULONG(argv[0]);
            break;
        case 1:
            scale_val = NUM2DBL(argv[0]);
            if (scale_val < 0.0)
            {
                rb_raise(rb_eArgError, "invalid scale_val value (%g given)", scale_val);
            }
            drows = scale_val * image->rows + 0.5;
            dcols = scale_val * image->columns + 0.5;
            if (drows > (double)ULONG_MAX || dcols > (double)ULONG_MAX)
            {
                rb_raise(rb_eRangeError, "resized image too big");
            }
            rows = (unsigned long) drows;
            columns = (unsigned long) dcols;
            break;
        default:
            rb_raise(rb_eArgError, "wrong number of arguments (%d for 1 or 2)", argc);
            break;
    }

    GetExceptionInfo(&exception);
    new_image = AdaptiveResizeImage(image, columns, rows, &exception);
    rm_check_exception(&exception, new_image, DestroyOnError);

    (void) DestroyExceptionInfo(&exception);
    rm_ensure_result(new_image);

    return rm_image_new(new_image);
}

#adaptive_sharpen(*args) ⇒ Object

Method: Image#adaptive_sharpen(radius=0.0, sigma=1.0) Purpose: call AdaptiveSharpenImage


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# File 'ext/RMagick/rmimage.c', line 201

VALUE
Image_adaptive_sharpen(int argc, VALUE *argv, VALUE self)
{
    return adaptive_method(argc, argv, self, AdaptiveSharpenImage);
}

#adaptive_sharpen_channel(*args) ⇒ Object

Method: Image#adaptive_sharpen_channel(radius=0.0, sigma=1.0[, channel…]) Purpose: Call AdaptiveSharpenImageChannel


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# File 'ext/RMagick/rmimage.c', line 213

VALUE
Image_adaptive_sharpen_channel(int argc, VALUE *argv, VALUE self)
{
    return adaptive_channel_method(argc, argv, self, AdaptiveSharpenImageChannel);
}

#adaptive_threshold(*args) ⇒ Object

Method: Image#adaptive_threshold(width=3, height=3, offset=0) Purpose: selects an individual threshold for each pixel based on

the range of intensity values in its local neighborhood.
This allows for thresholding of an image whose global
intensity histogram doesn't contain distinctive peaks.

Returns: a new image


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# File 'ext/RMagick/rmimage.c', line 229

VALUE
Image_adaptive_threshold(int argc, VALUE *argv, VALUE self)
{
    Image *image, *new_image;
    unsigned long width = 3, height = 3;
    long offset = 0;
    ExceptionInfo exception;

    image = rm_check_destroyed(self);

    switch (argc)
    {
        case 3:
            offset = NUM2LONG(argv[2]);
        case 2:
            height = NUM2ULONG(argv[1]);
        case 1:
            width  = NUM2ULONG(argv[0]);
        case 0:
            break;
        default:
            rb_raise(rb_eArgError, "wrong number of arguments (%d for 0 to 3)", argc);
    }

    GetExceptionInfo(&exception);
    new_image = AdaptiveThresholdImage(image, width, height, offset, &exception);
    rm_check_exception(&exception, new_image, DestroyOnError);

    (void) DestroyExceptionInfo(&exception);

    rm_ensure_result(new_image);

    return rm_image_new(new_image);
}

#add_compose_mask(mask) ⇒ Object

Method: Image#add_compose_mask(mask) Purpose: Set the image composite mask Ref: SetImageMask Notes: Returns self See also: Image#mask(), #delete_compose_mask()


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# File 'ext/RMagick/rmimage.c', line 272

VALUE
Image_add_compose_mask(VALUE self, VALUE mask)
{
    Image *image;
    Image *mask_image = NULL;

    image = rm_check_frozen(self);
    mask_image = rm_check_destroyed(mask);
    if (image->columns != mask_image->columns || image->rows != mask_image->rows)
    {
        rb_raise(rb_eArgError, "mask must be the same size as image");
    }

    // Delete any previously-existing mask image.
    // Store a clone of the new mask image.
    (void) SetImageMask(image, mask_image);
    (void) NegateImage(image->mask, MagickFalse);

    // Since both Set and GetImageMask clone the mask image I don't see any
    // way to negate the mask without referencing it directly. Sigh.

    return self;
}

#add_noise(noise) ⇒ Object

Method: Image#add_noise(noise_type) Purpose: add random noise to a copy of the image Returns: a new image


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# File 'ext/RMagick/rmimage.c', line 302

VALUE
Image_add_noise(VALUE self, VALUE noise)
{
    Image *image, *new_image;
    NoiseType noise_type;
    ExceptionInfo exception;

    image = rm_check_destroyed(self);

    VALUE_TO_ENUM(noise, noise_type, NoiseType);

    GetExceptionInfo(&exception);
    new_image = AddNoiseImage(image, noise_type, &exception);
    rm_check_exception(&exception, new_image, DestroyOnError);

    (void) DestroyExceptionInfo(&exception);

    rm_ensure_result(new_image);

    return rm_image_new(new_image);
}

#add_noise_channel(*args) ⇒ Object

Method: Image#add_noise_channel(noise_type) Purpose: add random noise to a copy of the image Returns: a new image


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# File 'ext/RMagick/rmimage.c', line 329

VALUE
Image_add_noise_channel(int argc, VALUE *argv, VALUE self)
{
    Image *image, *new_image;
    NoiseType noise_type;
    ExceptionInfo exception;
    ChannelType channels;

    image = rm_check_destroyed(self);
    channels = extract_channels(&argc, argv);

    // There must be 1 remaining argument.
    if (argc == 0)
    {
        rb_raise(rb_eArgError, "missing noise type argument");
    }
    else if (argc > 1)
    {
        raise_ChannelType_error(argv[argc-1]);
    }

    VALUE_TO_ENUM(argv[0], noise_type, NoiseType);
    channels &= ~OpacityChannel;

    GetExceptionInfo(&exception);
    new_image = AddNoiseImageChannel(image, channels, noise_type, &exception);
    rm_check_exception(&exception, new_image, DestroyOnError);

    (void) DestroyExceptionInfo(&exception);

    rm_ensure_result(new_image);

    return rm_image_new(new_image);
}

#add_profile(name) ⇒ Object

Method: Image#add_profile(name) Purpose: adds all the profiles in the specified file Notes: `name' is the profile filename


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# File 'ext/RMagick/rmimage.c', line 370

VALUE
Image_add_profile(VALUE self, VALUE name)
{
    // ImageMagick code based on the code for the "-profile" option in mogrify.c
    Image *image, *profile_image;
    ImageInfo *info;
    ExceptionInfo exception;
    char *profile_name;
    char *profile_filename = NULL;
    long profile_filename_l = 0;
    const StringInfo *profile;

    image = rm_check_frozen(self);

    // ProfileImage issues a warning if something goes wrong.
    profile_filename = rm_str2cstr(name, &profile_filename_l);

    info = CloneImageInfo(NULL);
    if (!info)
    {
        rb_raise(rb_eNoMemError, "not enough memory to continue");
    }
    profile = GetImageProfile(image, "iptc");
    if (profile)
    {
        info->profile = (void *)CloneStringInfo(profile);
    }
    strncpy(info->filename, profile_filename, min((size_t)profile_filename_l, sizeof(info->filename)));
    info->filename[MaxTextExtent-1] = '\0';

    GetExceptionInfo(&exception);
    profile_image = ReadImage(info, &exception);
    (void) DestroyImageInfo(info);
    rm_check_exception(&exception, profile_image, DestroyOnError);
    (void) DestroyExceptionInfo(&exception);
    rm_ensure_result(profile_image);

    ResetImageProfileIterator(profile_image);
    profile_name = GetNextImageProfile(profile_image);
    while (profile_name)
    {
        profile = GetImageProfile(profile_image, profile_name);
        if (profile)
        {
            (void)ProfileImage(image, profile_name, GetStringInfoDatum(profile)
                               , GetStringInfoLength(profile), MagickFalse);
            if (image->exception.severity >= ErrorException)
            {
                break;
            }
        }
        profile_name = GetNextImageProfile(profile_image);
    }

    (void) DestroyImage(profile_image);
    rm_check_image_exception(image, RetainOnError);


    return self;
}

#affine_transform(affine) ⇒ Object

Method: Image#affine_transform(affine_matrix) Purpose: transforms an image as dictated by the affine matrix argument Returns: a new image


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# File 'ext/RMagick/rmimage.c', line 543

VALUE
Image_affine_transform(VALUE self, VALUE affine)
{
    Image *image, *new_image;
    ExceptionInfo exception;
    AffineMatrix matrix;

    image = rm_check_destroyed(self);

    // Convert Magick::AffineMatrix to AffineMatrix structure.
    Export_AffineMatrix(&matrix, affine);

    GetExceptionInfo(&exception);
    new_image = AffineTransformImage(image, &matrix, &exception);
    rm_check_exception(&exception, new_image, DestroyOnError);

    (void) DestroyExceptionInfo(&exception);

    rm_ensure_result(new_image);

    return rm_image_new(new_image);
}

#alpha(*args) ⇒ Object

Method: Image#alpha(type) Purpose: Calls SetImageAlphaChannel Notes: Replaces matte=, alpha=

Originally there was an alpha attribute getter and setter.
These are replaced with alpha? and alpha(type). We
still define (but don't document) alpha=. For backward
compatibility, if this method is called without an argument,
make it act like the old alpha getter and return true if the
matte channel is active, false otherwise.

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# File 'ext/RMagick/rmimage.c', line 444

VALUE
Image_alpha(int argc, VALUE *argv, VALUE self)
{
    Image *image;
    AlphaChannelType alpha;


    // For backward compatibility, make alpha() act like alpha?
    if (argc == 0)
    {
        return Image_alpha_q(self);
    }
    else if (argc > 1)
    {
        rb_raise(rb_eArgError, "wrong number of arguments (%d for 1)", argc);
    }


    image = rm_check_frozen(self);
    VALUE_TO_ENUM(argv[0], alpha, AlphaChannelType);

#if defined(HAVE_SETIMAGEALPHACHANNEL)
    // Added in 6.3.6-9
    (void) SetImageAlphaChannel(image, alpha);
    rm_check_image_exception(image, RetainOnError);
#else
    switch (alpha)
    {
        case ActivateAlphaChannel:
            image->matte = MagickTrue;
            break;

        case DeactivateAlphaChannel:
            image->matte = MagickFalse;
            break;

        case ResetAlphaChannel:
            if (image->matte == MagickFalse)
            {
                (void) SetImageOpacity(image, OpaqueOpacity);
                rm_check_image_exception(image, RetainOnError);
            }
            break;

        case SetAlphaChannel:
            (void) CompositeImage(image, CopyOpacityCompositeOp, image, 0, 0);
            rm_check_image_exception(image, RetainOnError);
            break;

        default:
            rb_raise(rb_eArgError, "unknown AlphaChannelType value");
            break;
    }
#endif

    return argv[0];
}

#alpha?Boolean

Method: Image#alpha? Returns: true if the image's alpha channel is activated Notes: Replaces Image#matte

Returns:

  • (Boolean)

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# File 'ext/RMagick/rmimage.c', line 509

VALUE
Image_alpha_q(VALUE self)
{
    Image *image = rm_check_destroyed(self);
#if defined(HAVE_GETIMAGEALPHACHANNEL)
    return GetImageAlphaChannel(image) ? Qtrue : Qfalse;
#else
    return image->matte ? Qtrue : Qfalse;
#endif
}

#annotate(draw, width, height, x, y, text, &block) ⇒ Object

Provide an alternate version of Draw#annotate, for folks who want to find it in this class.


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# File 'lib/RMagick.rb', line 765

def annotate(draw, width, height, x, y, text, &block)
  check_destroyed
  draw.annotate(self, width, height, x, y, text, &block)
  self
end

#auto_orientObject


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# File 'ext/RMagick/rmimage.c', line 771

VALUE
Image_auto_orient(VALUE self)
{
    (void) rm_check_destroyed(self);
    return auto_orient(False, self);
}

#auto_orient!Object

Returns nil if the image is already properly oriented


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# File 'ext/RMagick/rmimage.c', line 782

VALUE
Image_auto_orient_bang(VALUE self)
{
    (void) rm_check_frozen(self);
    return auto_orient(True, self);
}

#bilevel_channel(*args) ⇒ Object

Method: Image#bilevel_channel(threshold, channel=AllChannels) Returns a new image


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# File 'ext/RMagick/rmimage.c', line 887

VALUE
Image_bilevel_channel(int argc, VALUE *argv, VALUE self)
{
    Image *image, *new_image;
    ChannelType channels;

    image = rm_check_destroyed(self);
    channels = extract_channels(&argc, argv);

    if (argc > 1)
    {
        raise_ChannelType_error(argv[argc-1]);
    }
    if (argc == 0)
    {
        rb_raise(rb_eArgError, "no threshold specified");
    }

    new_image = rm_clone_image(image);

    (void)BilevelImageChannel(new_image, channels, NUM2DBL(argv[0]));
    rm_check_image_exception(new_image, DestroyOnError);

    return rm_image_new(new_image);
}

#black_threshold(*args) ⇒ Object

Method: Image#black_threshold(red_channel [, green_channel

[, blue_channel [, opacity_channel]]]);

Purpose: Call BlackThresholdImage


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# File 'ext/RMagick/rmimage.c', line 964

VALUE
Image_black_threshold(int argc, VALUE *argv, VALUE self)
{
    return threshold_image(argc, argv, self, BlackThresholdImage);
}

#blend(*args) ⇒ Object

Method: Image#blend(overlay, src_percent, dst_percent, x_offset=0, y_offset=0)

Image#dissolve(overlay, src_percent, dst_percent, gravity, x_offset=0, y_offset=0)

Purpose: Corresponds to the composite -blend operation Notes: `percent' can be a number or a string in the form “NN%”

The default value for dst_percent is 100.0-src_percent

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# File 'ext/RMagick/rmimage.c', line 1237

VALUE
Image_blend(int argc, VALUE *argv, VALUE self)
{
    volatile VALUE ovly;
    Image *image, *overlay;
    double src_percent, dst_percent;
    long x_offset = 0L, y_offset = 0L;

    image = rm_check_destroyed(self);

    if (argc < 1)
    {
        rb_raise(rb_eArgError, "wrong number of arguments (%d for 2 to 6)", argc);
    }

    ovly = rm_cur_image(argv[0]);
    overlay = rm_check_destroyed(ovly);

    if (argc > 3)
    {
        get_composite_offsets(argc-3, &argv[3], image, overlay, &x_offset, &y_offset);
        // There must be 3 arguments left
        argc = 3;
    }

    switch (argc)
    {
        case 3:
            dst_percent = rm_percentage(argv[2]) * 100.0;
            src_percent = rm_percentage(argv[1]) * 100.0;
            break;
        case 2:
            src_percent = rm_percentage(argv[1]) * 100.0;
            dst_percent = FMAX(100.0 - src_percent, 0);
            break;
        default:
            rb_raise(rb_eArgError, "wrong number of arguments (%d for 2 to 6)", argc);
            break;
    }

    return special_composite(image, overlay, src_percent, dst_percent
                             , x_offset, y_offset, BlendCompositeOp);

}

#blur_channelObject

#blur_image(*args) ⇒ Object

Method: Image#blur_image(radius=0.0, sigma=1.0) Purpose: Blur the image Notes: The “blur” name is used for the attribute


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# File 'ext/RMagick/rmimage.c', line 1332

VALUE
Image_blur_image(int argc, VALUE *argv, VALUE self)
{
    return effect_image(self, argc, argv, BlurImage);
}

#border(width, height, color) ⇒ Object


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# File 'ext/RMagick/rmimage.c', line 1391

VALUE
Image_border(VALUE self, VALUE width, VALUE height, VALUE color)
{
    (void) rm_check_destroyed(self);
    return border(False, self, width, height, color);
}

#border!(width, height, color) ⇒ Object


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# File 'ext/RMagick/rmimage.c', line 1383

VALUE
Image_border_bang(VALUE self, VALUE width, VALUE height, VALUE color)
{
    (void) rm_check_frozen(self);
    return border(True, self, width, height, color);
}

#change_geometry(geom_arg) ⇒ Object

Method: Image#change_geometry(geometry_string) { |cols, rows, image| } Purpose: parse geometry string, compute new image geometry


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# File 'ext/RMagick/rmimage.c', line 1507

VALUE
Image_change_geometry(VALUE self, VALUE geom_arg)
{
    Image *image;
    RectangleInfo rect;
    volatile VALUE geom_str;
    char *geometry;
    unsigned int flags;
    volatile VALUE ary;

    image = rm_check_destroyed(self);
    geom_str = rm_to_s(geom_arg);
    geometry = StringValuePtr(geom_str);

    memset(&rect, 0, sizeof(rect));

    SetGeometry(image, &rect);
    rm_check_image_exception(image, RetainOnError);
    flags = ParseMetaGeometry(geometry, &rect.x,&rect.y, &rect.width,&rect.height);
    if (flags == NoValue)
    {
        rb_raise(rb_eArgError, "invalid geometry string `%s'", geometry);
    }

    ary = rb_ary_new2(3);
    rb_ary_store(ary, 0, ULONG2NUM(rect.width));
    rb_ary_store(ary, 1, ULONG2NUM(rect.height));
    rb_ary_store(ary, 2, self);

    return rb_yield(ary);
}

#change_geometry!(geom_arg) ⇒ Object

Method: Image#change_geometry(geometry_string) { |cols, rows, image| } Purpose: parse geometry string, compute new image geometry


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# File 'ext/RMagick/rmimage.c', line 1507

VALUE
Image_change_geometry(VALUE self, VALUE geom_arg)
{
    Image *image;
    RectangleInfo rect;
    volatile VALUE geom_str;
    char *geometry;
    unsigned int flags;
    volatile VALUE ary;

    image = rm_check_destroyed(self);
    geom_str = rm_to_s(geom_arg);
    geometry = StringValuePtr(geom_str);

    memset(&rect, 0, sizeof(rect));

    SetGeometry(image, &rect);
    rm_check_image_exception(image, RetainOnError);
    flags = ParseMetaGeometry(geometry, &rect.x,&rect.y, &rect.width,&rect.height);
    if (flags == NoValue)
    {
        rb_raise(rb_eArgError, "invalid geometry string `%s'", geometry);
    }

    ary = rb_ary_new2(3);
    rb_ary_store(ary, 0, ULONG2NUM(rect.width));
    rb_ary_store(ary, 1, ULONG2NUM(rect.height));
    rb_ary_store(ary, 2, self);

    return rb_yield(ary);
}

#changed?Boolean

Method: Image#changed? Purpose: Return true if any pixel in the image has been altered since

the image was constituted.

Returns:

  • (Boolean)

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# File 'ext/RMagick/rmimage.c', line 1545

VALUE
Image_changed_q(VALUE self)
{
    Image *image = rm_check_destroyed(self);
    VALUE okay = IsTaintImage(image) ? Qtrue : Qfalse;
    rm_check_image_exception(image, RetainOnError);
    return okay;
}

#channel(channel_arg) ⇒ Object

Method: Image#channel Purpose: Extract a channel from the image. A channel is a particular color

component of each pixel in the image.

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# File 'ext/RMagick/rmimage.c', line 1560

VALUE
Image_channel(VALUE self, VALUE channel_arg)
{
    Image *image, *new_image;
    ChannelType channel;

    image = rm_check_destroyed(self);

    VALUE_TO_ENUM(channel_arg, channel, ChannelType);

    new_image = rm_clone_image(image);

    (void) SeparateImageChannel(new_image, channel);

    rm_check_image_exception(new_image, DestroyOnError);
    rm_ensure_result(new_image);

    return rm_image_new(new_image);
}

#channel_compare(*args) ⇒ Object

Method: Image#compare_channel(ref_image, metric [, channel…]) { optional arguments } Purpose: compares one or more channels in two images and returns

the specified distortion metric and a comparison image.

Notes: If no channels are specified, the default is AllChannels.

That case is the equivalent of the CompareImages method in
ImageMagick.

Originally this method was called channel_compare, but
that doesn't match the general naming convention that
methods which accept multiple optional ChannelType
arguments have names that end in _channel.  So I renamed
the method to compare_channel but kept channel_compare as
an alias.

The optional arguments are specified thusly:
    self.highlight_color color
    self.lowlight-color color
where color is either a color name or a Pixel.

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# File 'ext/RMagick/rmimage.c', line 2348

VALUE
Image_compare_channel(int argc, VALUE *argv, VALUE self)
{
    Image *image, *r_image, *difference_image;
    double distortion;
    volatile VALUE ary, ref;
    MetricType metric_type;
    ChannelType channels;
    ExceptionInfo exception;

    image = rm_check_destroyed(self);

    channels = extract_channels(&argc, argv);

    if (argc > 2)
    {
        raise_ChannelType_error(argv[argc-1]);
    }
    if (argc != 2)
    {
        rb_raise(rb_eArgError, "wrong number of arguments (%d for 2 or more)", argc);
    }

    rm_get_optional_arguments(self);

    ref = rm_cur_image(argv[0]);
    r_image = rm_check_destroyed(ref);

    VALUE_TO_ENUM(argv[1], metric_type, MetricType);

    GetExceptionInfo(&exception);
    difference_image = CompareImageChannels(image
                                            , r_image
                                            , channels
                                            , metric_type
                                            , &distortion
                                            , &exception);
    rm_check_exception(&exception, difference_image, DestroyOnError);

    (void) DestroyExceptionInfo(&exception);

    rm_ensure_result(difference_image);

    ary = rb_ary_new2(2);
    rb_ary_store(ary, 0, rm_image_new(difference_image));
    rb_ary_store(ary, 1, rb_float_new(distortion));

    return ary;
}

#channel_depth(*args) ⇒ Object

Method: Image#channel_depth(channel_depth=AllChannels) Purpose: GetImageChannelDepth


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# File 'ext/RMagick/rmimage.c', line 1585

VALUE
Image_channel_depth(int argc, VALUE *argv, VALUE self)
{
    Image *image;
    ChannelType channels;
    unsigned long channel_depth;
    ExceptionInfo exception;

    image = rm_check_destroyed(self);
    channels = extract_channels(&argc, argv);

    // Ensure all arguments consumed.
    if (argc > 0)
    {
        raise_ChannelType_error(argv[argc-1]);
    }

    GetExceptionInfo(&exception);

    channel_depth = GetImageChannelDepth(image, channels, &exception);
    CHECK_EXCEPTION()

    (void) DestroyExceptionInfo(&exception);

    return ULONG2NUM(channel_depth);
}

#channel_extrema(*args) ⇒ Object

Method: Image#channel_extrema(channel=AllChannels) Purpose: Returns an array [min, max] where 'min' and 'max'

are the minimum and maximum values of all channels.

Notes: GM's implementation is very different from ImageMagick.

This method follows the IM API very closely and then
shoehorn's the GM API to more-or-less fit. Note that
IM allows you to specify more than one channel argument.
GM does not.

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# File 'ext/RMagick/rmimage.c', line 1623

VALUE
Image_channel_extrema(int argc, VALUE *argv, VALUE self)
{
    Image *image;
    ChannelType channels;
    ExceptionInfo exception;
    unsigned long min, max;
    volatile VALUE ary;

    image = rm_check_destroyed(self);

    channels = extract_channels(&argc, argv);

    // Ensure all arguments consumed.
    if (argc > 0)
    {
        raise_ChannelType_error(argv[argc-1]);
    }

    GetExceptionInfo(&exception);
    (void) GetImageChannelExtrema(image, channels, &min, &max, &exception);
    CHECK_EXCEPTION()

    (void) DestroyExceptionInfo(&exception);

    ary = rb_ary_new2(2);
    rb_ary_store(ary, 0, ULONG2NUM(min));
    rb_ary_store(ary, 1, ULONG2NUM(max));

    return ary;
}

#channel_mean(*args) ⇒ Object

Method: Image#channel_mean(channel=AllChannels) Returns An array [mean, std. deviation]


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# File 'ext/RMagick/rmimage.c', line 1660

VALUE
Image_channel_mean(int argc, VALUE *argv, VALUE self)
{
    Image *image;
    ChannelType channels;
    ExceptionInfo exception;
    double mean, stddev;
    volatile VALUE ary;

    image = rm_check_destroyed(self);

    channels = extract_channels(&argc, argv);

    // Ensure all arguments consumed.
    if (argc > 0)
    {
        raise_ChannelType_error(argv[argc-1]);
    }

    GetExceptionInfo(&exception);
    (void) GetImageChannelMean(image, channels, &mean, &stddev, &exception);
    CHECK_EXCEPTION()

    (void) DestroyExceptionInfo(&exception);

    ary = rb_ary_new2(2);
    rb_ary_store(ary, 0, rb_float_new(mean));
    rb_ary_store(ary, 1, rb_float_new(stddev));

    return ary;
}

#charcoal(*args) ⇒ Object

Method: Image#charcoal(radius=0.0, sigma=1.0) Purpose: Return a new image that is a copy of the input image with the

edges highlighted

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# File 'ext/RMagick/rmimage.c', line 1698

VALUE
Image_charcoal(int argc, VALUE *argv, VALUE self)
{
    return effect_image(self, argc, argv, CharcoalImage);
}

#check_destroyedObject

Method: Image#check_destroyed Purpose: If the target image has been destroyed, raises Magick::DestroyedImageError


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# File 'ext/RMagick/rmimage.c', line 1709

VALUE
Image_check_destroyed(VALUE self)
{
    (void) rm_check_destroyed(self);
    return Qnil;
}

#chop(x, y, width, height) ⇒ Object

Method: Image#chop Purpose: removes a region of an image and collapses the image to occupy

the removed portion

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# File 'ext/RMagick/rmimage.c', line 1722

VALUE
Image_chop(VALUE self, VALUE x, VALUE y, VALUE width, VALUE height)
{
    (void) rm_check_destroyed(self);
    return xform_image(False, self, x, y, width, height, ChopImage);
}

#cloneObject

Method: Image#clone Purpose: Copy an image, along with its frozen and tainted state.


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# File 'ext/RMagick/rmimage.c', line 1761

VALUE
Image_clone(VALUE self)
{
    volatile VALUE clone;

    clone = Image_dup(self);
    if (OBJ_FROZEN(self))
    {
        OBJ_FREEZE(clone);
    }

    return clone;
}

#clut_channel(*args) ⇒ Object

Method: Image#clut_channel Purpose: Equivalent to -clut option.


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# File 'ext/RMagick/rmimage.c', line 1780

VALUE
Image_clut_channel(int argc, VALUE *argv, VALUE self)
{
    Image *image, *clut;
    ChannelType channels;
    MagickBooleanType okay;

    image = rm_check_frozen(self);

    // check_destroyed before confirming the arguments
    if (argc >= 1)
    {
        (void) rm_check_destroyed(argv[0]);
        channels = extract_channels(&argc, argv);
        if (argc != 1)
        {
            rb_raise(rb_eArgError, "wrong number of arguments (%d for 1 or more)", argc);
        }
    }
    else
    {
        rb_raise(rb_eArgError, "wrong number of arguments (%d for 1 or more)", argc);
    }

    Data_Get_Struct(argv[0], Image, clut);

    okay = ClutImageChannel(image, channels, clut);
    rm_check_image_exception(image, RetainOnError);
    rm_check_image_exception(clut, RetainOnError);
    if (!okay)
    {
        rb_raise(rb_eRuntimeError, "ClutImageChannel failed.");
    }

    return self;
}

#color_fill_to_border(x, y, fill) ⇒ Object

Set all pixels that are neighbors of x,y and are not the border color to the fill color


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# File 'lib/RMagick.rb', line 787

def color_fill_to_border(x, y, fill)
    color_flood_fill(border_color, fill, x, y, Magick::FillToBorderMethod)
end

#color_flood_fill(target_color, fill_color, xv, yv, method) ⇒ Object

Method: Image#color_flood_fill(target_color, fill_color, x, y, method) Purpose: changes the color value of any pixel that matches target_color

and is an immediate neighbor.

Notes: use fuzz= to specify the tolerance amount (see Image_opaque)

Accepts either the FloodfillMethod or the FillToBorderMethod

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# File 'ext/RMagick/rmimage.c', line 2004

VALUE
Image_color_flood_fill( VALUE self, VALUE target_color, VALUE fill_color
                        , VALUE xv, VALUE yv, VALUE method)
{
    Image *image, *new_image;
    PixelPacket target;
    DrawInfo *draw_info;
    PixelPacket fill;
    long x, y;
    int fill_method;

    image = rm_check_destroyed(self);

    // The target and fill args can be either a color name or
    // a Magick::Pixel.
    Color_to_PixelPacket(&target, target_color);
    Color_to_PixelPacket(&fill, fill_color);

    x = NUM2LONG(xv);
    y = NUM2LONG(yv);
    if ((unsigned long)x > image->columns || (unsigned long)y > image->rows)
    {
        rb_raise(rb_eArgError, "target out of range. %lux%lu given, image is %lux%lu"
                 , x, y, image->columns, image->rows);
    }

    VALUE_TO_ENUM(method, fill_method, PaintMethod);
    if (!(fill_method == FloodfillMethod || fill_method == FillToBorderMethod))
    {
        rb_raise(rb_eArgError, "paint method must be FloodfillMethod or "
                 "FillToBorderMethod (%d given)", fill_method);
    }

    draw_info = CloneDrawInfo(NULL, NULL);
    if (!draw_info)
    {
        rb_raise(rb_eNoMemError, "not enough memory to continue");
    }
    draw_info->fill = fill;

    new_image = rm_clone_image(image);

#if defined(HAVE_FLOODFILLPAINTIMAGE)
    {
        MagickPixelPacket target_mpp;
        MagickBooleanType invert;

        GetMagickPixelPacket(new_image, &target_mpp);
        if (fill_method == FillToBorderMethod)
        {
            invert = MagickTrue;
            target_mpp.red   = (MagickRealType) image->border_color.red;
            target_mpp.green = (MagickRealType) image->border_color.green;
            target_mpp.blue  = (MagickRealType) image->border_color.blue;
        }
        else
        {
            invert = MagickFalse;
            target_mpp.red   = (MagickRealType) target.red;
            target_mpp.green = (MagickRealType) target.green;
            target_mpp.blue  = (MagickRealType) target.blue;
        }

        (void) FloodfillPaintImage(new_image, DefaultChannels, draw_info, &target_mpp, x, y, invert);
    }
#else
    (void) ColorFloodfillImage(new_image, draw_info, target, x, y, (PaintMethod)fill_method);
#endif
    // No need to check for error

    (void) DestroyDrawInfo(draw_info);
    return rm_image_new(new_image);
}

#color_floodfill(x, y, fill) ⇒ Object

Set all pixels that have the same color as the pixel at x,y and are neighbors to the fill color


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# File 'lib/RMagick.rb', line 780

def color_floodfill(x, y, fill)
    target = pixel_color(x, y)
    color_flood_fill(target, fill, x, y, Magick::FloodfillMethod)
end

#color_histogramObject

Method: Image_color_histogram(VALUE self); Purpose: Call GetImageHistogram Notes: returns hash aPixel=>count


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# File 'ext/RMagick/rmimage.c', line 1823

VALUE
Image_color_histogram(VALUE self)
{
    Image *image, *dc_copy = NULL;
    volatile VALUE hash, pixel;
    unsigned long x, colors;
    ColorPacket *histogram;
    ExceptionInfo exception;

    image = rm_check_destroyed(self);

    // If image not DirectClass make a DirectClass copy.
    if (image->storage_class != DirectClass)
    {
        dc_copy = rm_clone_image(image);
        (void) SyncImage(dc_copy);
        magick_free(dc_copy->colormap);
        dc_copy->colormap = NULL;
        dc_copy->storage_class = DirectClass;
        image = dc_copy;
    }

    GetExceptionInfo(&exception);
    histogram = GetImageHistogram(image, &colors, &exception);

    if (histogram == NULL)
    {
        if (dc_copy)
        {
            (void) DestroyImage(dc_copy);
        }
        rb_raise(rb_eNoMemError, "not enough memory to continue");
    }
    if (exception.severity != UndefinedException)
    {
        (void) RelinquishMagickMemory(histogram);
        rm_check_exception(&exception, dc_copy, DestroyOnError);
    }

    (void) DestroyExceptionInfo(&exception);

    hash = rb_hash_new();
    for (x = 0; x < colors; x++)
    {
        pixel = Pixel_from_PixelPacket(&histogram[x].pixel);
        (void) rb_hash_aset(hash, pixel, ULONG2NUM((unsigned long)histogram[x].count));
    }

    /*
        Christy evidently didn't agree with Bob's memory management.
    */
    (void) RelinquishMagickMemory(histogram);

    if (dc_copy)
    {
        // Do not trace destruction
        (void) DestroyImage(dc_copy);
    }

    return hash;
}

#color_point(x, y, fill) ⇒ Object

Set the color at x,y


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# File 'lib/RMagick.rb', line 772

def color_point(x, y, fill)
    f = copy
    f.pixel_color(x, y, fill)
    return f
end

#color_reset!(fill) ⇒ Object

Set all pixels to the fill color. Very similar to Image#erase! Accepts either String or Pixel arguments


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# File 'lib/RMagick.rb', line 793

def color_reset!(fill)
    save = background_color
    # Change the background color _outside_ the begin block
    # so that if this object is frozen the exeception will be
    # raised before we have to handle it explicitly.
    self.background_color = fill
    begin
        erase!
    ensure
        self.background_color = save
    end
    self
end

#colorize(*args) ⇒ Object

Method: Image#colorize(r, g, b, target) Purpose: blends the fill color specified by “target” with each pixel in

the image. Specify the percentage blend for each r, g, b
component.

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# File 'ext/RMagick/rmimage.c', line 2085

VALUE
Image_colorize(int argc, VALUE *argv, VALUE self)
{
    Image *image, *new_image;
    double red, green, blue, matte;
    char opacity[50];
    PixelPacket target;
    ExceptionInfo exception;

    image = rm_check_destroyed(self);

    if (argc == 4)
    {
        red   = floor(100*NUM2DBL(argv[0])+0.5);
        green = floor(100*NUM2DBL(argv[1])+0.5);
        blue  = floor(100*NUM2DBL(argv[2])+0.5);
        Color_to_PixelPacket(&target, argv[3]);
        sprintf(opacity, "%f/%f/%f", red, green, blue);
    }
    else if (argc == 5)
    {
        red   = floor(100*NUM2DBL(argv[0])+0.5);
        green = floor(100*NUM2DBL(argv[1])+0.5);
        blue  = floor(100*NUM2DBL(argv[2])+0.5);
        matte = floor(100*NUM2DBL(argv[3])+0.5);
        Color_to_PixelPacket(&target, argv[4]);
        sprintf(opacity, "%f/%f/%f/%f", red, green, blue, matte);
    }
    else
    {
        rb_raise(rb_eArgError, "wrong number of arguments (%d for 4 or 5)", argc);
    }

    GetExceptionInfo(&exception);
    new_image = ColorizeImage(image, opacity, target, &exception);
    rm_check_exception(&exception, new_image, DestroyOnError);

    (void) DestroyExceptionInfo(&exception);

    rm_ensure_result(new_image);

    return rm_image_new(new_image);
}

#colormap(*args) ⇒ Object

Method: Image#colormap(index<, new-color>) Purpose: return the color in the colormap at the specified index. If

a new color is specified, replaces the color at the index
with the new color.

Returns: the name of the color. Notes: The “new-color” argument can be either a color name or

a Magick::Pixel.

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# File 'ext/RMagick/rmimage.c', line 2139

VALUE
Image_colormap(int argc, VALUE *argv, VALUE self)
{
    Image *image;
    unsigned long idx;
    PixelPacket color, new_color;

    image = rm_check_destroyed(self);

    // We can handle either 1 or 2 arguments. Nothing else.
    if (argc == 0 || argc > 2)
    {
        rb_raise(rb_eArgError, "wrong number of arguments (%d for 1 or 2)", argc);
    }

    idx = NUM2ULONG(argv[0]);
    if (idx > QuantumRange)
    {
        rb_raise(rb_eIndexError, "index out of range");
    }

    // If this is a simple "get" operation, ensure the image has a colormap.
    if (argc == 1)
    {
        if (!image->colormap)
        {
            rb_raise(rb_eIndexError, "image does not contain a colormap");
        }
        // Validate the index

        if (idx > image->colors-1)
        {
            rb_raise(rb_eIndexError, "index out of range");
        }
        return rm_pixelpacket_to_color_name(image, &image->colormap[idx]);
    }

    // This is a "set" operation. Things are different.

    rb_check_frozen(self);

    // Replace with new color? The arg can be either a color name or
    // a Magick::Pixel.
    Color_to_PixelPacket(&new_color, argv[1]);

    // Handle no colormap or current colormap too small.
    if (!image->colormap || idx > image->colors-1)
    {
        PixelPacket black;
        unsigned long i;

        memset(&black, 0, sizeof(black));

        if (!image->colormap)
        {
            image->colormap = (PixelPacket *)magick_safe_malloc((idx+1), sizeof(PixelPacket));
            image->colors = 0;
        }
        else
        {
            image->colormap = (PixelPacket *)magick_safe_realloc(image->colormap, (idx+1), sizeof(PixelPacket));
        }

        for (i = image->colors; i < idx; i++)
        {
            image->colormap[i] = black;
        }
        image->colors = idx+1;
    }

    // Save the current color so we can return it. Set the new color.
    color = image->colormap[idx];
    image->colormap[idx] = new_color;

    return rm_pixelpacket_to_color_name(image, &color);
}

#compare_channel(*args) ⇒ Object

Method: Image#compare_channel(ref_image, metric [, channel…]) { optional arguments } Purpose: compares one or more channels in two images and returns

the specified distortion metric and a comparison image.

Notes: If no channels are specified, the default is AllChannels.

That case is the equivalent of the CompareImages method in
ImageMagick.

Originally this method was called channel_compare, but
that doesn't match the general naming convention that
methods which accept multiple optional ChannelType
arguments have names that end in _channel.  So I renamed
the method to compare_channel but kept channel_compare as
an alias.

The optional arguments are specified thusly:
    self.highlight_color color
    self.lowlight-color color
where color is either a color name or a Pixel.

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# File 'ext/RMagick/rmimage.c', line 2348

VALUE
Image_compare_channel(int argc, VALUE *argv, VALUE self)
{
    Image *image, *r_image, *difference_image;
    double distortion;
    volatile VALUE ary, ref;
    MetricType metric_type;
    ChannelType channels;
    ExceptionInfo exception;

    image = rm_check_destroyed(self);

    channels = extract_channels(&argc, argv);

    if (argc > 2)
    {
        raise_ChannelType_error(argv[argc-1]);
    }
    if (argc != 2)
    {
        rb_raise(rb_eArgError, "wrong number of arguments (%d for 2 or more)", argc);
    }

    rm_get_optional_arguments(self);

    ref = rm_cur_image(argv[0]);
    r_image = rm_check_destroyed(ref);

    VALUE_TO_ENUM(argv[1], metric_type, MetricType);

    GetExceptionInfo(&exception);
    difference_image = CompareImageChannels(image
                                            , r_image
                                            , channels
                                            , metric_type
                                            , &distortion
                                            , &exception);
    rm_check_exception(&exception, difference_image, DestroyOnError);

    (void) DestroyExceptionInfo(&exception);

    rm_ensure_result(difference_image);

    ary = rb_ary_new2(2);
    rb_ary_store(ary, 0, rm_image_new(difference_image));
    rb_ary_store(ary, 1, rb_float_new(distortion));

    return ary;
}

#composite(*args) ⇒ Object


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# File 'ext/RMagick/rmimage.c', line 2595

VALUE
Image_composite(int argc, VALUE *argv, VALUE self)
{
    return composite(False, argc, argv, self, DefaultChannels);
}

#composite!(*args) ⇒ Object


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# File 'ext/RMagick/rmimage.c', line 2588

VALUE
Image_composite_bang(int argc, VALUE *argv, VALUE self)
{
    return composite(True, argc, argv, self, DefaultChannels);
}

#composite_affine(source, affine_matrix) ⇒ Object

Method: Image#composite_affine(composite, affine_matrix) Purpose: composites the source over the destination image as

dictated by the affine transform.

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# File 'ext/RMagick/rmimage.c', line 2607

VALUE
Image_composite_affine(VALUE self, VALUE source, VALUE affine_matrix)
{
    Image *image, *composite_image, *new_image;
    AffineMatrix affine;

    image = rm_check_destroyed(self);
    composite_image = rm_check_destroyed(source);
    new_image = rm_clone_image(image);

    Export_AffineMatrix(&affine, affine_matrix);
    (void) DrawAffineImage(new_image, composite_image, &affine);
    rm_check_image_exception(new_image, DestroyOnError);

    return rm_image_new(new_image);
}

#composite_channel(*args) ⇒ Object


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# File 'ext/RMagick/rmimage.c', line 2653

VALUE
Image_composite_channel(int argc, VALUE *argv, VALUE self)
{
    return composite_channel(False, argc, argv, self);
}

#composite_channel!(*args) ⇒ Object


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# File 'ext/RMagick/rmimage.c', line 2660

VALUE
Image_composite_channel_bang(int argc, VALUE *argv, VALUE self)
{
    return composite_channel(True, argc, argv, self);
}

#composite_tiled(*args) ⇒ Object


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# File 'ext/RMagick/rmimage.c', line 2743

VALUE
Image_composite_tiled(int argc, VALUE *argv, VALUE self)
{
    return composite_tiled(False, argc, argv, self);
}

#composite_tiled!(*args) ⇒ Object


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# File 'ext/RMagick/rmimage.c', line 2750

VALUE
Image_composite_tiled_bang(int argc, VALUE *argv, VALUE self)
{
    return composite_tiled(True, argc, argv, self);
}

#compress_colormap!Object

Method: Image#compress_colormap! Purpose: call CompressImageColormap Notes: API was CompressColormap until 5.4.9


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# File 'ext/RMagick/rmimage.c', line 2782

VALUE
Image_compress_colormap_bang(VALUE self)
{
    Image *image = rm_check_frozen(self);
    (void) CompressImageColormap(image);
    rm_check_image_exception(image, RetainOnError);

    return self;
}

#contrast(*args) ⇒ Object

Method: Image#contrast(<sharpen>) Purpose: enhances the intensity differences between the lighter and

darker elements of the image. Set sharpen to "true" to
increase the image contrast otherwise the contrast is reduced.

Notes: if omitted, “sharpen” defaults to 0 Returns: new contrasted image


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# File 'ext/RMagick/rmimage.c', line 2931

VALUE
Image_contrast(int argc, VALUE *argv, VALUE self)
{
    Image *image, *new_image;
    unsigned int sharpen = 0;

    image = rm_check_destroyed(self);
    if (argc > 1)
    {
        rb_raise(rb_eArgError, "wrong number of arguments (%d for 0 or 1)", argc);
    }
    else if (argc == 1)
    {
        sharpen = RTEST(argv[0]);
    }

    new_image = rm_clone_image(image);

    (void) ContrastImage(new_image, sharpen);
    rm_check_image_exception(new_image, DestroyOnError);

    return rm_image_new(new_image);
}

#contrast_stretch_channel(*args) ⇒ Object

Method: Image#contrast_stretch_channel(black_point <, white_point> <, channel…>) Purpose: Call ContrastStretchImageChannel Notes: If white_point is not specified then it is #pixels-black_point.

Both black_point and white_point can be specified as Floats
or as percentages, i.e. "10%"

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# File 'ext/RMagick/rmimage.c', line 3017

VALUE
Image_contrast_stretch_channel(int argc, VALUE *argv, VALUE self)
{
    Image *image, *new_image;
    ChannelType channels;
    double black_point, white_point;

    image = rm_check_destroyed(self);
    channels = extract_channels(&argc, argv);
    if (argc > 2)
    {
        raise_ChannelType_error(argv[argc-1]);
    }

    get_black_white_point(image, argc, argv, &black_point, &white_point);

    new_image = rm_clone_image(image);

    (void) ContrastStretchImageChannel(new_image, channels, black_point, white_point);
    rm_check_image_exception(new_image, DestroyOnError);

    return rm_image_new(new_image);
}

#convolve(order_arg, kernel_arg) ⇒ Object

Method: Image#convolve(order, kernel) Purpose: apply a custom convolution kernel to the image Notes: “order” is the number of rows and columns in the kernel

"kernel" is an order**2 array of doubles

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# File 'ext/RMagick/rmimage.c', line 3047

VALUE
Image_convolve(VALUE self, VALUE order_arg, VALUE kernel_arg)
{
    Image *image, *new_image;
    double *kernel;
    unsigned int x, order;
    ExceptionInfo exception;

    image = rm_check_destroyed(self);

    order = NUM2UINT(order_arg);

    kernel_arg = rb_Array(kernel_arg);
    rm_check_ary_len(kernel_arg, (long)(order*order));

    // Convert the kernel array argument to an array of doubles

    kernel = (double *)ALLOC_N(double, order*order);
    for (x = 0; x < order*order; x++)
    {
        kernel[x] = NUM2DBL(rb_ary_entry(kernel_arg, (long)x));
    }

    GetExceptionInfo(&exception);

    new_image = ConvolveImage((const Image *)image, order, (double *)kernel, &exception);
    xfree((void *)kernel);
    rm_check_exception(&exception, new_image, DestroyOnError);

    (void) DestroyExceptionInfo(&exception);

    rm_ensure_result(new_image);

    return rm_image_new(new_image);
}

#convolve_channel(*args) ⇒ Object

Method: Image#convolve_channel(order, kernel[, channel[, channel…]]) Purpose: call ConvolveImageChannel


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# File 'ext/RMagick/rmimage.c', line 3088

VALUE
Image_convolve_channel(int argc, VALUE *argv, VALUE self)
{
    Image *image, *new_image;
    double *kernel;
    volatile VALUE ary;
    unsigned int x, order;
    ChannelType channels;
    ExceptionInfo exception;

    image = rm_check_destroyed(self);

    channels = extract_channels(&argc, argv);

    // There are 2 required arguments.
    if (argc > 2)
    {
        raise_ChannelType_error(argv[argc-1]);
    }
    if (argc != 2)
    {
        rb_raise(rb_eArgError, "wrong number of arguments (%d for 2 or more)", argc);
    }

    order = NUM2UINT(argv[0]);
    ary = argv[1];

    rm_check_ary_len(ary, (long)(order*order));

    kernel = ALLOC_N(double, (long)(order*order));

    // Convert the kernel array argument to an array of doubles
    for (x = 0; x < order*order; x++)
    {
        kernel[x] = NUM2DBL(rb_ary_entry(ary, (long)x));
    }

    GetExceptionInfo(&exception);

    new_image = ConvolveImageChannel(image, channels, order, kernel, &exception);
    xfree((void *)kernel);
    rm_check_exception(&exception, new_image, DestroyOnError);

    (void) DestroyExceptionInfo(&exception);

    rm_ensure_result(new_image);

    return rm_image_new(new_image);
}

#copyObject

Method: Image#copy Purpose: Alias for dup


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# File 'ext/RMagick/rmimage.c', line 3144

VALUE
Image_copy(VALUE self)
{
    return rb_funcall(self, rm_ID_dup, 0);
}

#crop(*args) ⇒ Object

Method: Image#crop(x, y, width, height)

Image#crop(gravity, width, height)
Image#crop!(x, y, width, height)
Image#crop!(gravity, width, height)

Purpose: Extract a region of the image defined by width, height, x, y


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# File 'ext/RMagick/rmimage.c', line 3174

VALUE
Image_crop(int argc, VALUE *argv, VALUE self)
{
    (void) rm_check_destroyed(self);
    return cropper(False, argc, argv, self);
}

#crop!(*args) ⇒ Object


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# File 'ext/RMagick/rmimage.c', line 3182

VALUE
Image_crop_bang(int argc, VALUE *argv, VALUE self)
{
    (void) rm_check_frozen(self);
    return cropper(True, argc, argv, self);
}

#cur_imageObject

Used by ImageList methods - see ImageList#cur_image


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# File 'lib/RMagick.rb', line 808

def cur_image
    self
end

#cycle_colormap(amount) ⇒ Object

Method: Image#cycle_colormap Purpose: Call CycleColormapImage


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# File 'ext/RMagick/rmimage.c', line 3194

VALUE
Image_cycle_colormap(VALUE self, VALUE amount)
{
    Image *image, *new_image;
    int amt;

    image = rm_check_destroyed(self);

    new_image = rm_clone_image(image);
    amt = NUM2INT(amount);
    (void) CycleColormapImage(new_image, amt);
    // No need to check for an error

    return rm_image_new(new_image);
}

#decipher(passphrase) ⇒ Object

Method: Image#decipher(passphrase) Purpose: call DecipherImage


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# File 'ext/RMagick/rmimage.c', line 3301

VALUE
Image_decipher(VALUE self, VALUE passphrase)
{
#if defined(HAVE_ENCIPHERIMAGE)
    Image *image, *new_image;
    char *pf;
    ExceptionInfo exception;
    MagickBooleanType okay;

    image = rm_check_destroyed(self);
    pf = StringValuePtr(passphrase);      // ensure passphrase is a string
    GetExceptionInfo(&exception);

    new_image = rm_clone_image(image);

    okay = DecipherImage(new_image, pf, &exception);
    rm_check_exception(&exception, new_image, DestroyOnError);
    if (!okay)
    {
        new_image = DestroyImage(new_image);
        rb_raise(rb_eRuntimeError, "DecipherImage failed for unknown reason.");
    }

    DestroyExceptionInfo(&exception);

    return rm_image_new(new_image);
#else
    self = self;
    passphrase = passphrase;
    rm_not_implemented();
    return(VALUE)0;
#endif
}

#define(artifact, value) ⇒ Object

Method: value = Image#define(artifact, value) Purpose: Call SetImageArtifact Note: Normally a script should never call this method. Any calls

to SetImageArtifact will be part of the methods in which they're
needed, or be called via the OptionalMethodArguments class.

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# File 'ext/RMagick/rmimage.c', line 3343

VALUE
Image_define(VALUE self, VALUE artifact, VALUE value)
{
#if defined(HAVE_SETIMAGEARTIFACT)
    Image *image;
    char *key, *val;
    MagickBooleanType status;

    image = rm_check_frozen(self);
    artifact = rb_String(artifact);
    key = StringValuePtr(artifact);

    if (value == Qnil)
    {
        (void) DeleteImageArtifact(image, key);
    }
    else
    {
        value = rb_String(value);
        val = StringValuePtr(value);
        status = SetImageArtifact(image, key, val);
        if (!status)
        {
            rb_raise(rb_eNoMemError, "not enough memory to continue");
        }
    }

    return value;
#else
    rm_not_implemented();
    artifact = artifact;
    value = value;
    self = self;
    return(VALUE)0;
#endif
}

#delete_compose_maskObject

#delete_profile(name) ⇒ Object

Method: Image#delete_profile(name) Purpose: call ProfileImage Notes: name is the name of the profile to be deleted


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# File 'ext/RMagick/rmimage.c', line 3409

VALUE
Image_delete_profile(VALUE self, VALUE name)
{
    Image *image = rm_check_frozen(self);
    (void) ProfileImage(image, StringValuePtr(name), NULL, 0, MagickTrue);
    rm_check_image_exception(image, RetainOnError);

    return self;
}

#deskew(*args) ⇒ Object

Method: Image#deskew(threshold=0.40, auto-crop-width) Purpose: Implement convert -deskew option


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# File 'ext/RMagick/rmimage.c', line 3450

VALUE
Image_deskew(int argc, VALUE *argv, VALUE self)
{
#if defined(HAVE_DESKEWIMAGE)
    Image *image, *new_image;
    double threshold = 40.0 * QuantumRange / 100.0;
    unsigned long width;
    char auto_crop_width[20];
    ExceptionInfo exception;

    image = rm_check_destroyed(self);

    switch (argc)
    {
        case 2:
            width = NUM2ULONG(argv[1]);
            memset(auto_crop_width, 0, sizeof(auto_crop_width));
            sprintf(auto_crop_width, "%ld", width);
            SetImageArtifact(image, "deskew:auto-crop", auto_crop_width);
        case 1:
            threshold = rm_percentage(argv[0]) * QuantumRange;
        case 0:
            break;
        default:
            rb_raise(rb_eArgError, "wrong number of arguments (%d for 1 or 2)", argc);
            break;
    }

    GetExceptionInfo(&exception);
    new_image = DeskewImage(image, threshold, &exception);
    CHECK_EXCEPTION()
    rm_ensure_result(new_image);

    (void) DestroyExceptionInfo(&exception);

    return rm_image_new(new_image);
#else
    self = self;        // defeat "unused parameter" message
    argv = argv;
    argc = argc;
    rm_not_implemented();
    return(VALUE)0;
#endif
}

#despeckleObject

Method: Image#despeckle Purpose: reduces the speckle noise in an image while preserving the

edges of the original image

Returns: a new image


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# File 'ext/RMagick/rmimage.c', line 3502

VALUE
Image_despeckle(VALUE self)
{
    Image *image, *new_image;
    ExceptionInfo exception;

    image = rm_check_destroyed(self);
    GetExceptionInfo(&exception);

    new_image = DespeckleImage(image, &exception);
    rm_check_exception(&exception, new_image, DestroyOnError);

    (void) DestroyExceptionInfo(&exception);

    rm_ensure_result(new_image);

    return rm_image_new(new_image);
}

#destroy!Object

Method: Image#destroy! Purpose: Free all the memory associated with an image


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# File 'ext/RMagick/rmimage.c', line 3526

VALUE
Image_destroy_bang(VALUE self)
{
    Image *image;

    rb_check_frozen(self);
    Data_Get_Struct(self, Image, image);
    rm_image_destroy(image);
    DATA_PTR(self) = NULL;
    return self;
}

#destroyed?Boolean

Method: Image#destroyed? Purpose: Returns true if the image has been destroyed, false otherwise

Returns:

  • (Boolean)

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# File 'ext/RMagick/rmimage.c', line 3543

VALUE
Image_destroyed_q(VALUE self)
{
    Image *image;

    Data_Get_Struct(self, Image, image);
    return image ? Qfalse : Qtrue;
}

#difference(other) ⇒ Object

Method: Image#difference Purpose: Call the IsImagesEqual function Returns: An array with 3 values:

[0] mean error per pixel
[1] normalized mean error
[2] normalized maximum error

Notes: “other” can be either an Image or an Image


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# File 'ext/RMagick/rmimage.c', line 3562

VALUE
Image_difference(VALUE self, VALUE other)
{
    Image *image;
    Image *image2;
    volatile VALUE mean, nmean, nmax;

    image = rm_check_destroyed(self);
    other = rm_cur_image(other);
    image2 = rm_check_destroyed(other);

    (void) IsImagesEqual(image, image2);
    // No need to check for error

    mean  = rb_float_new(image->error.mean_error_per_pixel);
    nmean = rb_float_new(image->error.normalized_mean_error);
    nmax  = rb_float_new(image->error.normalized_maximum_error);
    return rb_ary_new3(3, mean, nmean, nmax);
}

#dispatch(*args) ⇒ Object

Method: Image#dispatch(x, y, columns, rows, map <, float>) Purpose: Extracts pixel data from the image and returns it as an

array of pixels. The "x", "y", "width" and "height" parameters
specify the rectangle to be extracted. The "map" parameter
reflects the expected ordering of the pixel array. It can be
any combination or order of R = red, G = green, B = blue, A =
alpha, C = cyan, Y = yellow, M = magenta, K = black, or I =
intensity (for grayscale). If the "float" parameter is specified
and true, the pixel data is returned as floating-point numbers
in the range [0..1]. By default the pixel data is returned as
integers in the range [0..QuantumRange].

Returns: an Array Raises: ArgumentError


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# File 'ext/RMagick/rmimage.c', line 3649

VALUE
Image_dispatch(int argc, VALUE *argv, VALUE self)
{
    Image *image;
    long x, y;
    unsigned long columns, rows, n, npixels;
    volatile VALUE pixels_ary;
    StorageType stg_type = QuantumPixel;
    char *map;
    long mapL;
    MagickBooleanType okay;
    ExceptionInfo exception;
    volatile union
    {
        Quantum *i;
        double *f;
        void *v;
    } pixels;

    (void) rm_check_destroyed(self);

    if (argc < 5 || argc > 6)
    {
        rb_raise(rb_eArgError, "wrong number of arguments (%d for 5 or 6)", argc);
    }

    x       = NUM2LONG(argv[0]);
    y       = NUM2LONG(argv[1]);
    columns = NUM2ULONG(argv[2]);
    rows    = NUM2ULONG(argv[3]);
    map     = rm_str2cstr(argv[4], &mapL);
    if (argc == 6)
    {
        stg_type = RTEST(argv[5]) ? DoublePixel : QuantumPixel;
    }

    // Compute the size of the pixel array and allocate the memory.
    npixels = columns * rows * mapL;
    pixels.v = stg_type == QuantumPixel ? (void *) ALLOC_N(Quantum, npixels)
               : (void *) ALLOC_N(double, npixels);

    // Create the Ruby array for the pixels. Return this even if ExportImagePixels fails.
    pixels_ary = rb_ary_new();

    Data_Get_Struct(self, Image, image);

    GetExceptionInfo(&exception);
    okay = ExportImagePixels(image, x, y, columns, rows, map, stg_type, (void *)pixels.v, &exception);

    if (!okay)
    {
        goto exit;
    }

    CHECK_EXCEPTION()

    (void) DestroyExceptionInfo(&exception);

    // Convert the pixel data to the appropriate Ruby type
    if (stg_type == QuantumPixel)
    {
        for (n = 0; n < npixels; n++)
        {
            (void) rb_ary_push(pixels_ary, QUANTUM2NUM(pixels.i[n]));
        }
    }
    else
    {
        for (n = 0; n < npixels; n++)
        {
            (void) rb_ary_push(pixels_ary, rb_float_new(pixels.f[n]));
        }
    }

    exit:
    xfree((void *)pixels.v);
    return pixels_ary;
}

#displaceObject

#displayObject Also known as: __display__

Method: Image#display Purpose: display the image to an X window screen


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# File 'ext/RMagick/rmimage.c', line 3733

VALUE
Image_display(VALUE self)
{
    Image *image;
    Info *info;
    volatile VALUE info_obj;

    image = rm_check_destroyed(self);

    if (image->rows == 0 || image->columns == 0)
    {
        rb_raise(rb_eArgError, "invalid image geometry (%lux%lu)", image->rows, image->columns);
    }

    info_obj = rm_info_new();
    Data_Get_Struct(info_obj, Info, info);

    (void) DisplayImages(info, image);
    rm_check_image_exception(image, RetainOnError);

    return self;
}

#dissolve(*args) ⇒ Object

Method: Image#dissolve(overlay, src_percent, dst_percent, x_offset=0, y_offset=0)

Image#dissolve(overlay, src_percent, dst_percent, gravity, x_offset=0, y_offset=0)

Purpose: Corresponds to the composite_image -dissolve operation Notes: `percent' can be a number or a string in the form “NN%”

The "default" value of dst_percent is -1.0, which tells
blend_geometry to leave it out of the geometry string.

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# File 'ext/RMagick/rmimage.c', line 3790

VALUE
Image_dissolve(int argc, VALUE *argv, VALUE self)
{
    Image *image, *overlay;
    double src_percent, dst_percent = -1.0;
    long x_offset = 0L, y_offset = 0L;
    volatile VALUE composite_image, ovly;

    image = rm_check_destroyed(self);

    if (argc < 1)
    {
        rb_raise(rb_eArgError, "wrong number of arguments (%d for 2 to 6)", argc);
    }

    ovly = rm_cur_image(argv[0]);
    overlay = rm_check_destroyed(ovly);

    if (argc > 3)
    {
        get_composite_offsets(argc-3, &argv[3], image, overlay, &x_offset, &y_offset);
        // There must be 3 arguments left
        argc = 3;
    }

    switch (argc)
    {
        case 3:
            dst_percent = rm_percentage(argv[2]) * 100.0;
        case 2:
            src_percent = rm_percentage(argv[1]) * 100.0;
            break;
        default:
            rb_raise(rb_eArgError, "wrong number of arguments (%d for 2 to 6)", argc);
            break;
    }

    composite_image =  special_composite(image, overlay, src_percent, dst_percent
                                         , x_offset, y_offset, DissolveCompositeOp);

    return composite_image;
}

#distort(*args) ⇒ Object

Method: Image#distort(type, points, bestfit=false) { optional arguments } Purpose: Call DistortImage Notes: points is an Array of Numeric values

optional arguments are
  self.define "distort:viewport", WxH+X+Y
  self.define "distort:scale", N
  self.verbose true

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# File 'ext/RMagick/rmimage.c', line 3845

VALUE
Image_distort(int argc, VALUE *argv, VALUE self)
{
    Image *image, *new_image;
    volatile VALUE pts;
    unsigned long n, npoints;
    DistortImageMethod distortion_method;
    double *points;
    MagickBooleanType bestfit = MagickFalse;
    ExceptionInfo exception;

    image = rm_check_destroyed(self);
    rm_get_optional_arguments(self);

    switch (argc)
    {
        case 3:
            bestfit = RTEST(argv[2]);
        case 2:
            // Ensure pts is an array
            pts = rb_Array(argv[1]);
            VALUE_TO_ENUM(argv[0], distortion_method, DistortImageMethod);
            break;
        default:
            rb_raise(rb_eArgError, "wrong number of arguments (expected 2 or 3, got %d)", argc);
            break;
    }

    npoints = RARRAY_LEN(pts);
    // Allocate points array from Ruby's memory. If an error occurs Ruby will
    // be able to clean it up.
    points = ALLOC_N(double, npoints);

    for (n = 0; n < npoints; n++)
    {
        points[n] = NUM2DBL(rb_ary_entry(pts, n));
    }

    GetExceptionInfo(&exception);
    new_image = DistortImage(image, distortion_method, npoints, points, bestfit, &exception);
    xfree(points);
    rm_check_exception(&exception, new_image, DestroyOnError);
    (void) DestroyExceptionInfo(&exception);
    rm_ensure_result(new_image);

    return rm_image_new(new_image);
}

#distortion_channel(*args) ⇒ Object

Method: Image#distortion_channel(reconstructed_image, metric[, channel…]) Purpose: Call GetImageChannelDistortion


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# File 'ext/RMagick/rmimage.c', line 3898

VALUE
Image_distortion_channel(int argc, VALUE *argv, VALUE self)
{
    Image *image, *reconstruct;
    ChannelType channels;
    ExceptionInfo exception;
    MetricType metric;
    volatile VALUE rec;
    double distortion;

    image = rm_check_destroyed(self);
    channels = extract_channels(&argc, argv);
    if (argc > 2)
    {
        raise_ChannelType_error(argv[argc-1]);
    }
    if (argc < 2)
    {
        rb_raise(rb_eArgError, "wrong number of arguments (%d for 2 or more)", argc);
    }

    rec = rm_cur_image(argv[0]);
    reconstruct = rm_check_destroyed(rec);
    VALUE_TO_ENUM(argv[1], metric, MetricType);
    GetExceptionInfo(&exception);
    (void) GetImageChannelDistortion(image, reconstruct, channels
                                     , metric, &distortion, &exception);
    CHECK_EXCEPTION()

    (void) DestroyExceptionInfo(&exception);

    return rb_float_new(distortion);
}

#dupObject

Method: Image#dup Purpose: Construct a new image object and call initialize_copy


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# File 'ext/RMagick/rmimage.c', line 3999

VALUE
Image_dup(VALUE self)
{
    volatile VALUE dup;

    (void) rm_check_destroyed(self);
    dup = Data_Wrap_Struct(CLASS_OF(self), NULL, rm_image_destroy, NULL);
    if (rb_obj_tainted(self))
    {
        (void) rb_obj_taint(dup);
    }
    return rb_funcall(dup, rm_ID_initialize_copy, 1, self);
}

#each_iptc_datasetObject

Iterate over IPTC record number:dataset tags, yield for each non-nil dataset


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# File 'lib/RMagick.rb', line 870

def each_iptc_dataset
    Magick::IPTC.constants.each do |record|
        rec = Magick::IPTC.const_get(record)
        rec.constants.each do |dataset|
            data_field = get_iptc_dataset(rec.const_get(dataset))
            yield(dataset, data_field) unless data_field.nil?
        end
    end
    nil
end

#each_pixelObject

Thanks to Russell Norris!


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# File 'lib/RMagick.rb', line 813

def each_pixel
  get_pixels(0, 0, columns, rows).each_with_index do |p, n|
    yield(p, n%columns, n/columns)
  end
  self
end

#each_profileObject

Method: Image#each_profile Purpose: Iterate over image profiles Notes: ImageMagick only


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# File 'ext/RMagick/rmimage.c', line 4019

VALUE
Image_each_profile(VALUE self)
{
    Image *image;
    volatile VALUE ary, val;
    char *name;
    const StringInfo *profile;

    image = rm_check_destroyed(self);
    ResetImageProfileIterator(image);

    ary = rb_ary_new2(2);

    name = GetNextImageProfile(image);
    while (name)
    {
        rb_ary_store(ary, 0, rb_str_new2(name));

        profile = GetImageProfile(image, name);
        if (!profile)
        {
            rb_ary_store(ary, 1, Qnil);
        }
        else
        {
            rb_ary_store(ary, 1, rb_str_new((char *)profile->datum, (long)profile->length));
        }
        val = rb_yield(ary);
        name = GetNextImageProfile(image);
    }

    return val;
}

#edge(*args) ⇒ Object

Method: Image#edge(radius=0) Purpose: finds edges in an image. “radius” defines the radius of the

convolution filter. Use a radius of 0 and edge selects a
suitable radius

Returns: a new image


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# File 'ext/RMagick/rmimage.c', line 4061

VALUE
Image_edge(int argc, VALUE *argv, VALUE self)
{
    Image *image, *new_image;
    double radius = 0.0;
    ExceptionInfo exception;

    image = rm_check_destroyed(self);
    switch (argc)
    {
        case 1:
            radius = NUM2DBL(argv[0]);
        case 0:
            break;
        default:
            rb_raise(rb_eArgError, "wrong number of arguments (%d for 0 or 1)", argc);
            break;
    }

    GetExceptionInfo(&exception);

    new_image = EdgeImage(image, radius, &exception);
    rm_check_exception(&exception, new_image, DestroyOnError);

    (void) DestroyExceptionInfo(&exception);

    rm_ensure_result(new_image);

    return rm_image_new(new_image);
}

#emboss(*args) ⇒ Object

Method: Image#emboss(radius=0.0, sigma=1.0) Purpose: creates a grayscale image with a three-dimensional effect


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# File 'ext/RMagick/rmimage.c', line 4140

VALUE
Image_emboss(int argc, VALUE *argv, VALUE self)
{
    return effect_image(self, argc, argv, EmbossImage);
}

#encipher(passphrase) ⇒ Object

Method: Image#encipher(passphrase) Purpose: call EncipherImage


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# File 'ext/RMagick/rmimage.c', line 4151

VALUE
Image_encipher(VALUE self, VALUE passphrase)
{
#if defined(HAVE_ENCIPHERIMAGE)
    Image *image, *new_image;
    char *pf;
    ExceptionInfo exception;
    MagickBooleanType okay;

    image = rm_check_destroyed(self);
    pf = StringValuePtr(passphrase);      // ensure passphrase is a string
    GetExceptionInfo(&exception);

    new_image = rm_clone_image(image);

    okay = EncipherImage(new_image, pf, &exception);
    rm_check_exception(&exception, new_image, DestroyOnError);
    if (!okay)
    {
        new_image = DestroyImage(new_image);
        rb_raise(rb_eRuntimeError, "EncipherImage failed for unknown reason.");
    }

    DestroyExceptionInfo(&exception);

    return rm_image_new(new_image);
#else
    self = self;
    passphrase = passphrase;
    rm_not_implemented();
    return(VALUE)0;
#endif
}

#enhanceObject

Method: Image#enhance Purpose: applies a digital filter that improves the quality of a noisy image


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# File 'ext/RMagick/rmimage.c', line 4215

VALUE
Image_enhance(VALUE self)
{
    Image *image, *new_image;
    ExceptionInfo exception;

    image = rm_check_destroyed(self);
    GetExceptionInfo(&exception);

    new_image = EnhanceImage(image, &exception);
    rm_check_exception(&exception, new_image, DestroyOnError);

    (void) DestroyExceptionInfo(&exception);

    rm_ensure_result(new_image);

    return rm_image_new(new_image);
}

#equalizeObject

Method: Image#equalize Purpose: applies a histogram equalization to the image


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# File 'ext/RMagick/rmimage.c', line 4239

VALUE
Image_equalize(VALUE self)
{
    Image *image, *new_image;
    ExceptionInfo exception;

    image = rm_check_destroyed(self);
    GetExceptionInfo(&exception);
    new_image = rm_clone_image(image);

    (void) EqualizeImage(new_image);
    rm_check_image_exception(new_image, DestroyOnError);

    (void) DestroyExceptionInfo(&exception);

    return rm_image_new(new_image);
}

#equalize_channel(*args) ⇒ Object

Method: Image#equalize_channel Purpose: call EqualizeImageChannel


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# File 'ext/RMagick/rmimage.c', line 4262

VALUE
Image_equalize_channel(int argc, VALUE *argv, VALUE self)
{
#if defined(HAVE_EQUALIZEIMAGECHANNEL)
    Image *image, *new_image;
    ExceptionInfo exception;
    ChannelType channels;

    image = rm_check_destroyed(self);
    channels = extract_channels(&argc, argv);
    if (argc > 0)
    {
        raise_ChannelType_error(argv[argc-1]);
    }

    new_image = rm_clone_image(image);

    GetExceptionInfo(&exception);

    (void) EqualizeImageChannel(new_image, channels);

    rm_check_image_exception(new_image, DestroyOnError);
    (void) DestroyExceptionInfo(&exception);

    return rm_image_new(new_image);
#else
    argc = argc;
    argv = argv;
    self = self;
    rm_not_implemented();
    return(VALUE) 0;
#endif
}

#erase!Object

Method: Image#erase! Purpose: reset the image to the background color Notes: one of the very few Image methods that do not

return a new image.

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# File 'ext/RMagick/rmimage.c', line 4303

VALUE
Image_erase_bang(VALUE self)
{
    Image *image = rm_check_frozen(self);

    (void) SetImageBackgroundColor(image);
    rm_check_image_exception(image, RetainOnError);

    return self;
}

#excerpt(x, y, width, height) ⇒ Object


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# File 'ext/RMagick/rmimage.c', line 4353

VALUE
Image_excerpt(VALUE self, VALUE x, VALUE y, VALUE width, VALUE height)
{
    (void) rm_check_destroyed(self);
    return excerpt(False, self, x, y, width, height);
}

#excerpt!(x, y, width, height) ⇒ Object


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# File 'ext/RMagick/rmimage.c', line 4361

VALUE
Image_excerpt_bang(VALUE self, VALUE x, VALUE y, VALUE width, VALUE height)
{
    (void) rm_check_frozen(self);
    return excerpt(True, self, x, y, width, height);
}

#export_pixels(*args) ⇒ Object

Method: Image#export_pixels(x=0, y=0, cols=self.columns, rows=self.rows, map=“RGB”) Purpose: extract image pixels in the form of an array


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# File 'ext/RMagick/rmimage.c', line 4373

VALUE
Image_export_pixels(int argc, VALUE *argv, VALUE self)
{
    Image *image;
    long x_off = 0L, y_off = 0L;
    unsigned long cols, rows;
    long n, npixels;
    unsigned int okay;
    const char *map = "RGB";
    Quantum *pixels;
    volatile VALUE ary;
    ExceptionInfo exception;


    image = rm_check_destroyed(self);
    cols = image->columns;
    rows = image->rows;

    switch (argc)
    {
        case 5:
            map   = StringValuePtr(argv[4]);
        case 4:
            rows  = NUM2ULONG(argv[3]);
        case 3:
            cols  = NUM2ULONG(argv[2]);
        case 2:
            y_off = NUM2LONG(argv[1]);
        case 1:
            x_off = NUM2LONG(argv[0]);
        case 0:
            break;
        default:
            rb_raise(rb_eArgError, "wrong number of arguments (%d for 1 to 5)", argc);
            break;
    }

    if (   x_off < 0 || (unsigned long)x_off > image->columns
           || y_off < 0 || (unsigned long)y_off > image->rows
           || cols == 0 || rows == 0)
    {
        rb_raise(rb_eArgError, "invalid extract geometry");
    }


    npixels = (long)(cols * rows * strlen(map));
    pixels = ALLOC_N(Quantum, npixels);
    if (!pixels)    // app recovered from exception
    {
        return rb_ary_new2(0L);
    }

    GetExceptionInfo(&exception);

    okay = ExportImagePixels(image, x_off, y_off, cols, rows, map, QuantumPixel, (void *)pixels, &exception);
    if (!okay)
    {
        xfree((void *)pixels);
        CHECK_EXCEPTION()

        // Should never get here...
        rm_magick_error("ExportImagePixels failed with no explanation.", NULL);
    }

    (void) DestroyExceptionInfo(&exception);

    ary = rb_ary_new2(npixels);
    for (n = 0; n < npixels; n++)
    {
        (void) rb_ary_push(ary, QUANTUM2NUM(pixels[n]));
    }

    xfree((void *)pixels);

    return ary;
}

#export_pixels_to_str(*args) ⇒ Object

Method: Image#export_pixels_to_str(x=0, y=0, cols=self.columns,

rows=self.rows, map="RGB", type=Magick::CharPixel)

Purpose: extract image pixels to a Ruby string


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# File 'ext/RMagick/rmimage.c', line 4514

VALUE
Image_export_pixels_to_str(int argc, VALUE *argv, VALUE self)
{
    Image *image;
    long x_off = 0L, y_off = 0L;
    unsigned long cols, rows;
    unsigned long npixels;
    size_t sz;
    unsigned int okay;
    const char *map = "RGB";
    StorageType type = CharPixel;
    volatile VALUE string;
    char *str;
    ExceptionInfo exception;

    image = rm_check_destroyed(self);
    cols = image->columns;
    rows = image->rows;

    switch (argc)
    {
        case 6:
            VALUE_TO_ENUM(argv[5], type, StorageType);
        case 5:
            map   = StringValuePtr(argv[4]);
        case 4:
            rows  = NUM2ULONG(argv[3]);
        case 3:
            cols  = NUM2ULONG(argv[2]);
        case 2:
            y_off = NUM2LONG(argv[1]);
        case 1:
            x_off = NUM2LONG(argv[0]);
        case 0:
            break;
        default:
            rb_raise(rb_eArgError, "wrong number of arguments (%d for 1 to 6)", argc);
            break;
    }

    if (   x_off < 0 || (unsigned long)x_off > image->columns
           || y_off < 0 || (unsigned long)y_off > image->rows
           || cols == 0 || rows == 0)
    {
        rb_raise(rb_eArgError, "invalid extract geometry");
    }


    npixels = cols * rows * strlen(map);
    switch (type)
    {
        case CharPixel:
            sz = sizeof(unsigned char);
            break;
        case ShortPixel:
            sz = sizeof(unsigned short);
            break;
        case DoublePixel:
            sz = sizeof(double);
            break;
        case FloatPixel:
            sz = sizeof(float);
            break;
        case IntegerPixel:
            sz = sizeof(unsigned int);
            break;
        case LongPixel:
            sz = sizeof(unsigned long);
            break;
        case QuantumPixel:
            sz = sizeof(Quantum);
            break;
        case UndefinedPixel:
        default:
            rb_raise(rb_eArgError, "undefined storage type");
            break;
    }

    // Allocate a string long enough to hold the exported pixel data.
    // Get a pointer to the buffer.
    string = rb_str_new2("");
    (void) rb_str_resize(string, (long)(sz * npixels));
    str = StringValuePtr(string);

    GetExceptionInfo(&exception);

    okay = ExportImagePixels(image, x_off, y_off, cols, rows, map, type, (void *)str, &exception);
    if (!okay)
    {
        // Let GC have the string buffer.
        (void) rb_str_resize(string, 0);
        CHECK_EXCEPTION()

        // Should never get here...
        rm_magick_error("ExportImagePixels failed with no explanation.", NULL);
    }

    (void) DestroyExceptionInfo(&exception);

    return string;
}

#extent(*args) ⇒ Object

Method: Image#extent(width, height, x=0, y=0) Purpose: Call ExtentImage


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# File 'ext/RMagick/rmimage.c', line 4455

VALUE
Image_extent(int argc, VALUE *argv, VALUE self)
{
    Image *image, *new_image;
    RectangleInfo geometry;
    long height, width;
    ExceptionInfo exception;

    (void) rm_check_destroyed(self);

    if (argc < 2 || argc > 4)
    {
        rb_raise(rb_eArgError, "wrong number of arguments (expected 2 to 4, got %d)", argc);
    }

    geometry.y = geometry.x = 0L;
    switch (argc)
    {
        case 4:
            geometry.y = NUM2LONG(argv[3]);
        case 3:
            geometry.x = NUM2LONG(argv[2]);
        default:
            geometry.height = height = NUM2LONG(argv[1]);
            geometry.width = width = NUM2LONG(argv[0]);
            break;
    }

    // Use the signed versions of these two values to test for < 0
    if (height <= 0L || width <= 0L)
    {
        if (geometry.x == 0 && geometry.y == 0)
        {
            rb_raise(rb_eArgError, "invalid extent geometry %ldx%ld", width, height);
        }
        else
        {
            rb_raise(rb_eArgError, "invalid extent geometry %ldx%ld+%ld+%ld"
                     , width, height, geometry.x, geometry.y);
        }
    }


    Data_Get_Struct(self, Image, image);
    GetExceptionInfo(&exception);

    new_image = ExtentImage(image, &geometry, &exception);
    rm_check_exception(&exception, new_image, DestroyOnError);
    (void) DestroyExceptionInfo(&exception);
    rm_ensure_result(new_image);
    return rm_image_new(new_image);
}

#find_similar_region(*args) ⇒ Object

Method: Image#find_similar_region(target, x=0, y=0) Purpose: Search for a region in the image that is “similar” to the

target image.

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# File 'ext/RMagick/rmimage.c', line 4678

VALUE
Image_find_similar_region(int argc, VALUE *argv, VALUE self)
{
    Image *image, *target;
    volatile VALUE region, targ;
    long x = 0L, y = 0L;
    ExceptionInfo exception;
    unsigned int okay;

    image = rm_check_destroyed(self);

    switch (argc)
    {
        case 3:
            y = NUM2LONG(argv[2]);
        case 2:
            x = NUM2LONG(argv[1]);
        case 1:
            targ = rm_cur_image(argv[0]);
            target = rm_check_destroyed(targ);
            break;
        default:
            rb_raise(rb_eArgError, "wrong number of arguments (%d for 1 to 3)", argc);
            break;
    }

    GetExceptionInfo(&exception);
    okay = IsImageSimilar(image, target, &x, &y, &exception);
    CHECK_EXCEPTION();
    (void) DestroyExceptionInfo(&exception);

    if (!okay)
    {
        return Qnil;
    }

    region = rb_ary_new2(2);
    rb_ary_store(region, 0L, LONG2NUM(x));
    rb_ary_store(region, 1L, LONG2NUM(y));

    return region;
}

#flipObject


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# File 'ext/RMagick/rmimage.c', line 4758

VALUE
Image_flip(VALUE self)
{
    (void) rm_check_destroyed(self);
    return flipflop(False, self, FlipImage);
}

#flip!Object


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# File 'ext/RMagick/rmimage.c', line 4766

VALUE
Image_flip_bang(VALUE self)
{
    (void) rm_check_frozen(self);
    return flipflop(True, self, FlipImage);
}

#flopObject

Method: Image#flop

Image#flop!

Purpose: creates a horizontal mirror image by reflecting the pixels around

the central y-axis

Returns: flop: a new, flopped image

flop!: self, flopped

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# File 'ext/RMagick/rmimage.c', line 4782

VALUE
Image_flop(VALUE self)
{
    (void) rm_check_destroyed(self);
    return flipflop(False, self, FlopImage);
}

#flop!Object


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# File 'ext/RMagick/rmimage.c', line 4790

VALUE
Image_flop_bang(VALUE self)
{
    (void) rm_check_frozen(self);
    return flipflop(True, self, FlopImage);
}

#frame(*args) ⇒ Object

Method: Image#frame(<width<, height<, x<, y<, inner_bevel<, outer_bevel

<, color>>>>>>>)

Purpose: adds a simulated three-dimensional border around the image.

"Width" and "height" specify the width and height of the frame.
The "x" and "y" arguments position the image within the frame.
If the image is supposed to be centered in the frame, x and y
should be 1/2 the width and height of the frame. (I.e. if the
frame is 50 pixels high and 50 pixels wide, x and y should both
be 25)."Inner_bevel" and "outer_bevel" indicate the width of the
inner and outer shadows of the frame. They should be much
smaller than the frame and cannot be > 1/2 the frame width or
height of the image.

Default: All arguments are optional. The defaults are the same as they

are in Magick++:

width:  image-columns+25*2
height: image-rows+25*2
x:      25
y:      25
inner:  6
outer:  6
color:  image matte_color (which defaults to #bdbdbd, whatever
        self.matte_color was set to when the image was created,
        or whatever image.matte_color is currently set to)

Returns: a new image.


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# File 'ext/RMagick/rmimage.c', line 4886

VALUE
Image_frame(int argc, VALUE *argv, VALUE self)
{
    Image *image, *new_image;
    ExceptionInfo exception;
    FrameInfo frame_info;

    image = rm_check_destroyed(self);

    frame_info.width = image->columns + 50;
    frame_info.height = image->rows + 50;
    frame_info.x = 25;
    frame_info.y = 25;
    frame_info.inner_bevel = 6;
    frame_info.outer_bevel = 6;

    switch (argc)
    {
        case 7:
            Color_to_PixelPacket(&image->matte_color, argv[6]);
        case 6:
            frame_info.outer_bevel = NUM2LONG(argv[5]);
        case 5:
            frame_info.inner_bevel = NUM2LONG(argv[4]);
        case 4:
            frame_info.y = NUM2LONG(argv[3]);
        case 3:
            frame_info.x = NUM2LONG(argv[2]);
        case 2:
            frame_info.height = image->rows + 2*NUM2LONG(argv[1]);
        case 1:
            frame_info.width = image->columns + 2*NUM2LONG(argv[0]);
        case 0:
            break;
        default:
            rb_raise(rb_eArgError, "wrong number of arguments (%d for 0 to 7)", argc);
            break;
    }

    GetExceptionInfo(&exception);
    new_image = FrameImage(image, &frame_info, &exception);
    rm_check_exception(&exception, new_image, DestroyOnError);

    (void) DestroyExceptionInfo(&exception);

    rm_ensure_result(new_image);

    return rm_image_new(new_image);
}

#gamma_channelObject

#gamma_correct(*args) ⇒ Object

Method: Image#gamma_correct(red_gamma<, green_gamma<, blue_gamma>>>) Purpose: gamma-correct an image Notes: At least red_gamma must be specified. If one or more levels are

omitted, the last specified number is used as the default.
For backward compatibility accept a 4th argument but ignore it.

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# File 'ext/RMagick/rmimage.c', line 5033

VALUE
Image_gamma_correct(int argc, VALUE *argv, VALUE self)
{
    Image *image, *new_image;
    double red_gamma, green_gamma, blue_gamma;
    char gamma_arg[50];

    image = rm_check_destroyed(self);
    switch (argc)
    {
        case 1:
            red_gamma   = NUM2DBL(argv[0]);

            // Can't have all 4 gamma values == 1.0. Also, very small values
            // cause ImageMagick to segv.
            if (red_gamma == 1.0 || fabs(red_gamma) < 0.003)
            {
                rb_raise(rb_eArgError, "invalid gamma value (%f)", red_gamma);
            }
            green_gamma = blue_gamma = red_gamma;
            break;
        case 2:
            red_gamma   = NUM2DBL(argv[0]);
            green_gamma = NUM2DBL(argv[1]);
            blue_gamma  = green_gamma;
            break;
        case 3:
        case 4:
            red_gamma     = NUM2DBL(argv[0]);
            green_gamma   = NUM2DBL(argv[1]);
            blue_gamma    = NUM2DBL(argv[2]);
            break;
        default:
            rb_raise(rb_eArgError, "wrong number of arguments (%d for 1 to 3)", argc);
            break;
    }

    sprintf(gamma_arg, "%f,%f,%f", red_gamma, green_gamma, blue_gamma);

    new_image = rm_clone_image(image);

    (void) GammaImage(new_image, gamma_arg);
    rm_check_image_exception(new_image, DestroyOnError);

    return rm_image_new(new_image);
}

#gaussian_blur(*args) ⇒ Object

Method: Image#gaussian_blur(radius, sigma) Purpose: blur the image Returns: a new image


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# File 'ext/RMagick/rmimage.c', line 5086

VALUE
Image_gaussian_blur(int argc, VALUE *argv, VALUE self)
{
    return effect_image(self, argc, argv, GaussianBlurImage);
}

#gaussian_blur_channel(*args) ⇒ Object

Method: Image#gaussian_blur_channel(radius=0, sigma=1, channel=AllChannels) Notes: new in IM 6.0.0


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# File 'ext/RMagick/rmimage.c', line 5097

VALUE
Image_gaussian_blur_channel(int argc, VALUE *argv, VALUE self)
{
    Image *image, *new_image;
    ChannelType channels;
    ExceptionInfo exception;
    double radius = 0.0, sigma = 1.0;

    image = rm_check_destroyed(self);
    channels = extract_channels(&argc, argv);

    // There can be 0, 1, or 2 remaining arguments.
    switch (argc)
    {
        case 2:
            sigma = NUM2DBL(argv[1]);
            /* Fall thru */
        case 1:
            radius = NUM2DBL(argv[0]);
            /* Fall thru */
        case 0:
            break;
        default:
            raise_ChannelType_error(argv[argc-1]);
    }

    GetExceptionInfo(&exception);
    new_image = GaussianBlurImageChannel(image, channels, radius, sigma, &exception);
    rm_check_exception(&exception, new_image, DestroyOnError);

    (void) DestroyExceptionInfo(&exception);

    return rm_image_new(new_image);
}

#get_exif_by_entry(*entry) ⇒ Object

Retrieve EXIF data by entry or all. If one or more entry names specified, return the values associated with the entries. If no entries specified, return all entries and values. The return value is an array of [name,value] arrays.


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# File 'lib/RMagick.rb', line 824

def get_exif_by_entry(*entry)
    ary = Array.new
    if entry.length == 0
        exif_data = self['EXIF:*']
        if exif_data
            exif_data.split("\n").each { |exif| ary.push(exif.split('=')) }
        end
    else
        get_exif_by_entry()     # ensure properties is populated with exif data
        entry.each do |name|
            rval = self["EXIF:#{name}"]
            ary.push([name, rval])
        end
    end
    return ary
end

#get_exif_by_number(*tag) ⇒ Object

Retrieve EXIF data by tag number or all tag/value pairs. The return value is a hash.


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# File 'lib/RMagick.rb', line 842

def get_exif_by_number(*tag)
    hash = Hash.new
    if tag.length == 0
        exif_data = self['EXIF:!']
        if exif_data
            exif_data.split("\n").each do |exif|
                tag, value = exif.split('=')
                tag = tag[1,4].hex
                hash[tag] = value
            end
        end
    else
        get_exif_by_number()    # ensure properties is populated with exif data
        tag.each do |num|
            rval = self['#%04X' % num.to_i]
            hash[num] = rval == 'unknown' ? nil : rval
        end
    end
    return hash
end

#get_iptc_dataset(ds) ⇒ Object

Retrieve IPTC information by record number:dataset tag constant defined in Magick::IPTC, above.


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# File 'lib/RMagick.rb', line 865

def get_iptc_dataset(ds)
    self['IPTC:'+ds]
end

#get_pixels(x_arg, y_arg, cols_arg, rows_arg) ⇒ Object

Method: Image#get_pixels(x, y, columns. rows) Purpose: Call AcquireImagePixels Returns: An array of Magick::Pixel objects corresponding to the pixels in

the rectangle defined by the geometry parameters.

Note: This is the complement of store_pixels. Notice that the

return value is an array object even when only one pixel is
returned.
store_pixels calls GetImagePixels, then SyncImage

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# File 'ext/RMagick/rmimage.c', line 5180

VALUE
Image_get_pixels(VALUE self, VALUE x_arg, VALUE y_arg, VALUE cols_arg, VALUE rows_arg)
{
    Image *image;
    const PixelPacket *pixels;
    ExceptionInfo exception;
    long x, y;
    unsigned long columns, rows;
    long size, n;
    VALUE pixel_ary;

    image = rm_check_destroyed(self);
    x       = NUM2LONG(x_arg);
    y       = NUM2LONG(y_arg);
    columns = NUM2ULONG(cols_arg);
    rows    = NUM2ULONG(rows_arg);

    if ((x+columns) > image->columns || (y+rows) > image->rows)
    {
        rb_raise(rb_eRangeError, "geometry (%lux%lu%+ld%+ld) exceeds image bounds"
                 , columns, rows, x, y);
    }

    // Cast AcquireImagePixels to get rid of the const qualifier. We're not going
    // to change the pixels but I don't want to make "pixels" const.
    GetExceptionInfo(&exception);
#if defined(HAVE_GETVIRTUALPIXELS)
    pixels = GetVirtualPixels(image, x, y, columns, rows, &exception);
#else
    pixels = AcquireImagePixels(image, x, y, columns, rows, &exception);
#endif
    CHECK_EXCEPTION()

    (void) DestroyExceptionInfo(&exception);

    // If the function failed, return a 0-length array.
    if (!pixels)
    {
        return rb_ary_new();
    }

    // Allocate an array big enough to contain the PixelPackets.
    size = (long)(columns * rows);
    pixel_ary = rb_ary_new2(size);

    // Convert the PixelPackets to Magick::Pixel objects
    for (n = 0; n < size; n++)
    {
        rb_ary_store(pixel_ary, n, Pixel_from_PixelPacket(&pixels[n]));
    }

    return pixel_ary;
}

#gray?Boolean

Method: Image#gray? Purpose: return true if all the pixels in the image have the same red,

green, and blue intensities.

Returns:

  • (Boolean)

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# File 'ext/RMagick/rmimage.c', line 5257

VALUE
Image_gray_q(VALUE self)
{
    return has_attribute(self, (MagickBooleanType (*)(const Image *, ExceptionInfo *))IsGrayImage);
}

#grey?Boolean

Method: Image#gray? Purpose: return true if all the pixels in the image have the same red,

green, and blue intensities.

Returns:

  • (Boolean)

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# File 'ext/RMagick/rmimage.c', line 5257

VALUE
Image_gray_q(VALUE self)
{
    return has_attribute(self, (MagickBooleanType (*)(const Image *, ExceptionInfo *))IsGrayImage);
}

#histogram?Boolean

Method: Image#histogram? Purpose: return true if has 1024 unique colors or less.

Returns:

  • (Boolean)

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# File 'ext/RMagick/rmimage.c', line 5268

VALUE
Image_histogram_q(VALUE self)
{
    return has_attribute(self, IsHistogramImage);
}

#implode(*args) ⇒ Object

Method: Image#implode(amount=0.50) Purpose: implode the image by the specified percentage Returns: a new image


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# File 'ext/RMagick/rmimage.c', line 5280

VALUE
Image_implode(int argc, VALUE *argv, VALUE self)
{
    Image *image, *new_image;
    double amount = 0.50;
    ExceptionInfo exception;

    switch (argc)
    {
        case 1:
            amount = NUM2DBL(argv[0]);
        case 0:
            break;
        default:
            rb_raise(rb_eArgError, "wrong number of arguments (%d for 0 or 1)", argc);
    }

    image = rm_check_destroyed(self);
    GetExceptionInfo(&exception);

    new_image = ImplodeImage(image, amount, &exception);
    rm_check_exception(&exception, new_image, DestroyOnError);
    (void) DestroyExceptionInfo(&exception);

    rm_ensure_result(new_image);

    return rm_image_new(new_image);
}

#import_pixels(*args) ⇒ Object

Method: Image#import_pixels Purpose: store image pixel data from an array Notes: See Image#export_pixels


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# File 'ext/RMagick/rmimage.c', line 5315

VALUE
Image_import_pixels(int argc, VALUE *argv, VALUE self)
{
    Image *image;
    long x_off, y_off;
    unsigned long cols, rows;
    unsigned long n, npixels;
    long buffer_l;
    char *map;
    volatile VALUE pixel_arg, pixel_ary;
    StorageType stg_type = CharPixel;
    size_t type_sz, map_l;
    Quantum *pixels = NULL;
    double *fpixels = NULL;
    void *buffer;
    unsigned int okay;

    image = rm_check_frozen(self);

    switch (argc)
    {
        case 7:
            VALUE_TO_ENUM(argv[6], stg_type, StorageType);
        case 6:
            x_off = NUM2LONG(argv[0]);
            y_off = NUM2LONG(argv[1]);
            cols = NUM2ULONG(argv[2]);
            rows = NUM2ULONG(argv[3]);
            map = StringValuePtr(argv[4]);
            pixel_arg = argv[5];
            break;
        default:
            rb_raise(rb_eArgError, "wrong number of arguments (%d for 6 or 7)", argc);
            break;
    }

    if (x_off < 0 || y_off < 0 || cols <= 0 || rows <= 0)
    {
        rb_raise(rb_eArgError, "invalid import geometry");
    }

    map_l = strlen(map);
    npixels = cols * rows * map_l;

    // Assume that any object that responds to :to_str is a string buffer containing
    // binary pixel data.
    if (rb_respond_to(pixel_arg, rb_intern("to_str")))
    {
        buffer = (void *)rm_str2cstr(pixel_arg, &buffer_l);
        switch (stg_type)
        {
            case CharPixel:
                type_sz = 1;
                break;
            case ShortPixel:
                type_sz = sizeof(unsigned short);
                break;
            case IntegerPixel:
                type_sz = sizeof(unsigned int);
                break;
            case LongPixel:
                type_sz = sizeof(unsigned long);
                break;
            case DoublePixel:
                type_sz = sizeof(double);
                break;
            case FloatPixel:
                type_sz = sizeof(float);
                break;
            case QuantumPixel:
                type_sz = sizeof(Quantum);
                break;
            default:
                rb_raise(rb_eArgError, "unsupported storage type %s", StorageType_name(stg_type));
                break;
        }

        if (buffer_l % type_sz != 0)
        {
            rb_raise(rb_eArgError, "pixel buffer must be an exact multiple of the storage type size");
        }
        if ((buffer_l / type_sz) % map_l != 0)
        {
            rb_raise(rb_eArgError, "pixel buffer must contain an exact multiple of the map length");
        }
        if ((unsigned long)(buffer_l / type_sz) < npixels)
        {
            rb_raise(rb_eArgError, "pixel buffer too small (need %lu channel values, got %ld)"
                     , npixels, buffer_l/type_sz);
        }
    }
    // Otherwise convert the argument to an array and convert the array elements
    // to binary pixel data.
    else
    {
        // rb_Array converts an object that is not an array to an array if possible,
        // and raises TypeError if it can't. It usually is possible.
        pixel_ary = rb_Array(pixel_arg);

        if (RARRAY_LEN(pixel_ary) % map_l != 0)
        {
            rb_raise(rb_eArgError, "pixel array must contain an exact multiple of the map length");
        }
        if ((unsigned long)RARRAY_LEN(pixel_ary) < npixels)
        {
            rb_raise(rb_eArgError, "pixel array too small (need %lu elements, got %ld)"
                     , npixels, RARRAY_LEN(pixel_ary));
        }

        if (stg_type == DoublePixel || stg_type == FloatPixel)
        {
            // Get an array for double pixels. Use Ruby's memory so GC will clean up after
            // us in case of an exception.
            fpixels = ALLOC_N(double, npixels);
            for (n = 0; n < npixels; n++)
            {
                fpixels[n] = NUM2DBL(rb_ary_entry(pixel_ary, n));
            }
            buffer = (void *) fpixels;
            stg_type = DoublePixel;
        }
        else
        {
            // Get array for Quantum pixels. Use Ruby's memory so GC will clean up after us
            // in case of an exception.
            pixels = ALLOC_N(Quantum, npixels);
            for (n = 0; n < npixels; n++)
            {
                volatile VALUE p = rb_ary_entry(pixel_ary, n);
                pixels[n] = NUM2QUANTUM(p);
            }
            buffer = (void *) pixels;
            stg_type = QuantumPixel;
        }
    }


    okay = ImportImagePixels(image, x_off, y_off, cols, rows, map, stg_type, buffer);

    // Free pixel array before checking for errors.
    if (pixels)
    {
        xfree((void *)pixels);
    }
    if (fpixels)
    {
        xfree((void *)fpixels);
    }

    if (!okay)
    {
        rm_check_image_exception(image, RetainOnError);
        // Shouldn't get here...
        rm_magick_error("ImportImagePixels failed with no explanation.", NULL);
    }

    return self;
}

#initialize_copy(orig) ⇒ Object

Method: Image#initialize_copy Purpose: initialize copy, clone, dup


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# File 'ext/RMagick/rmimage.c', line 3154

VALUE
Image_init_copy(VALUE copy, VALUE orig)
{
    Image *image, *new_image;

    image = rm_check_destroyed(orig);
    new_image = rm_clone_image(image);
    UPDATE_DATA_PTR(copy, new_image);

    return copy;
}

#inspectObject


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# File 'ext/RMagick/rmimage.c', line 5613

VALUE
Image_inspect(VALUE self)
{
    Image *image;
    char buffer[MaxTextExtent];          // image description buffer

    Data_Get_Struct(self, Image, image);
    if (!image)
    {
        return rb_str_new2("#<Magick::Image: (destroyed)>");
    }
    build_inspect_string(image, buffer, sizeof(buffer));
    return rb_str_new2(buffer);
}

#level(black_point = 0.0, white_point = nil, gamma = nil) ⇒ Object

(Thanks to Al Evans for the suggestion.)


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# File 'lib/RMagick.rb', line 894

def level(black_point=0.0, white_point=nil, gamma=nil)
    black_point = Float(black_point)

    white_point ||= Magick::QuantumRange - black_point
    white_point = Float(white_point)

    gamma_arg = gamma
    gamma ||= 1.0
    gamma = Float(gamma)

    if gamma.abs > 10.0 || white_point.abs <= 10.0 || white_point.abs < gamma.abs
        gamma, white_point = white_point, gamma
        unless gamma_arg
            white_point = Magick::QuantumRange - black_point
        end
    end

    return level2(black_point, white_point, gamma)
end

#level2Object

#level_channel(*args) ⇒ Object

Method: Image#level_channel(aChannelType, black=0, white=QuantumRange, gamma=1.0) Purpose: similar to Image#level but applies to a single channel only Notes: black and white are 0-QuantumRange, gamma is 0-10.


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# File 'ext/RMagick/rmimage.c', line 5753

VALUE
Image_level_channel(int argc, VALUE *argv, VALUE self)
{
    Image *image, *new_image;
    double black_point = 0.0, gamma_val = 1.0, white_point = (double)QuantumRange;
    ChannelType channel;

    image = rm_check_destroyed(self);
    switch (argc)
    {
        case 1:             // take all the defaults
            break;
        case 2:
            black_point = NUM2DBL(argv[1]);
            white_point = QuantumRange - black_point;
            break;
        case 3:
            black_point = NUM2DBL(argv[1]);
            white_point = NUM2DBL(argv[2]);
            break;
        case 4:
            black_point = NUM2DBL(argv[1]);
            white_point = NUM2DBL(argv[2]);
            gamma_val   = NUM2DBL(argv[3]);
            break;
        default:
            rb_raise(rb_eArgError, "wrong number of arguments (%d for 1 to 4)", argc);
            break;
    }

    VALUE_TO_ENUM(argv[0], channel, ChannelType);

    new_image = rm_clone_image(image);

    (void) LevelImageChannel(new_image, channel, black_point, white_point, gamma_val);
    rm_check_image_exception(new_image, DestroyOnError);

    return rm_image_new(new_image);
}

#level_colors(*args) ⇒ Object

Method: Image#level_colors(black_color=“black”, white_color=“white”, invert=true [, channel…]) Purpose: Implement +level_colors blank_color,white_color


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# File 'ext/RMagick/rmimage.c', line 5798

VALUE
Image_level_colors(int argc, VALUE *argv, VALUE self)
{
#if defined(HAVE_LEVELIMAGECOLORS)
    Image *image, *new_image;
    MagickPixelPacket black_color, white_color;
    ChannelType channels;
    ExceptionInfo exception;
    MagickBooleanType invert = MagickTrue;
    MagickBooleanType status;

    image = rm_check_destroyed(self);

    channels = extract_channels(&argc, argv);

    switch (argc)
    {
        case 3:
            invert = RTEST(argv[2]);

        case 2:
            Color_to_MagickPixelPacket(image, &white_color, argv[1]);
            Color_to_MagickPixelPacket(image, &black_color, argv[0]);
            break;

        case 1:
            Color_to_MagickPixelPacket(image, &black_color, argv[0]);
            GetExceptionInfo(&exception);

            GetMagickPixelPacket(image, &white_color);
            (void) QueryMagickColor("white", &white_color, &exception);
            CHECK_EXCEPTION()

            DestroyExceptionInfo(&exception);

        case 0:
            GetExceptionInfo(&exception);

            GetMagickPixelPacket(image, &white_color);
            (void) QueryMagickColor("white", &white_color, &exception);
            CHECK_EXCEPTION()

            GetMagickPixelPacket(image, &black_color);
            (void) QueryMagickColor("black", &black_color, &exception);
            CHECK_EXCEPTION()

            DestroyExceptionInfo(&exception);
            break;

        default:
            raise_ChannelType_error(argv[argc-1]);
            break;
    }

    new_image = rm_clone_image(image);

    status = LevelImageColors(new_image, channels, &black_color, &white_color, invert);
    rm_check_image_exception(new_image, DestroyOnError);
    if (!status)
    {
        rb_raise(rb_eRuntimeError, "LevelImageColors failed for unknown reason.");
    }

    return rm_image_new(new_image);

#else
    rm_not_implemented();
    self = self;
    argc = argc;
    argv = argv;
    return(VALUE)0;
#endif
}

#levelize_channel(*args) ⇒ Object

Method: Image#levelize_channel(black_point[, white_point[, gamma=1.0[, channel…]])


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# File 'ext/RMagick/rmimage.c', line 5877

VALUE
Image_levelize_channel(int argc, VALUE *argv, VALUE self)
{
#if defined(HAVE_LEVELIZEIMAGECHANNEL)
    Image *image, *new_image;
    ChannelType channels;
    double black_point, white_point;
    double gamma = 1.0;
    MagickBooleanType status;

    image = rm_check_destroyed(self);
    channels = extract_channels(&argc, argv);
    if (argc > 3)
    {
        raise_ChannelType_error(argv[argc-1]);
    }

    switch (argc)
    {
        case 3:
            gamma = NUM2DBL(argv[2]);
        case 2:
            white_point = NUM2DBL(argv[1]);
            black_point = NUM2DBL(argv[0]);
            break;
        case 1:
            black_point = NUM2DBL(argv[0]);
            white_point = QuantumRange - black_point;
            break;
        default:
            rb_raise(rb_eArgError, "wrong number of arguments (%d for 1 or more)", argc);
            break;
    }

    new_image = rm_clone_image(image);
    status = LevelizeImageChannel(new_image, channels, black_point, white_point, gamma);

    rm_check_image_exception(new_image, DestroyOnError);
    if (!status)
    {
        rb_raise(rb_eRuntimeError, "LevelizeImageChannel failed for unknown reason.");
    }
    return rm_image_new(new_image);
#else
    rm_not_implemented();
    self = self;
    argc = argc;
    argv = argv;
    return(VALUE)0;
#endif
}

#linear_stretch(*args) ⇒ Object

Method: Image_linear_stretch(black_point <, white_point>) Purpose: Call LinearStretchImage Notes: The default for white_point is #pixels-black_point.

See Image_contrast_stretch_channel.

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# File 'ext/RMagick/rmimage.c', line 5936

VALUE
Image_linear_stretch(int argc, VALUE *argv, VALUE self)
{
    Image *image, *new_image;
    double black_point, white_point;

    image = rm_check_destroyed(self);
    get_black_white_point(image, argc, argv, &black_point, &white_point);
    new_image = rm_clone_image(image);

    (void) LinearStretchImage(new_image, black_point, white_point);
    rm_check_image_exception(new_image, DestroyOnError);

    return rm_image_new(new_image);
}

#liquid_rescale(*args) ⇒ Object

Method: Image#liquid_rescale(columns, rows, delta_x=0.0, rigidity=0.0) Purpose: Call the LiquidRescaleImage API


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# File 'ext/RMagick/rmimage.c', line 5957

VALUE
Image_liquid_rescale(int argc, VALUE *argv, VALUE self)
{
#if defined(HAVE_LIQUIDRESCALEIMAGE)
    Image *image, *new_image;
    unsigned long cols, rows;
    double delta_x = 0.0;
    double rigidity = 0.0;
    ExceptionInfo exception;

    image = rm_check_destroyed(self);

    switch (argc)
    {
        case 4:
            rigidity = NUM2DBL(argv[3]);
        case 3:
            delta_x = NUM2DBL(argv[2]);
        case 2:
            rows = NUM2ULONG(argv[1]);
            cols = NUM2ULONG(argv[0]);
            break;
        default:
            rb_raise(rb_eArgError, "wrong number of arguments (%d for 2 to 4)", argc);
            break;
    }

    GetExceptionInfo(&exception);
    new_image = LiquidRescaleImage(image, cols, rows, delta_x, rigidity, &exception);
    rm_check_exception(&exception, new_image, DestroyOnError);
    DestroyExceptionInfo(&exception);
    rm_ensure_result(new_image);

    return rm_image_new(new_image);
#else
    argc = argc;    // defeat "unused parameter" messages
    argv = argv;
    self = self;
    rm_not_implemented();
    return(VALUE)0;
#endif
}

#magnifyObject


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# File 'ext/RMagick/rmimage.c', line 6110

VALUE
Image_magnify(VALUE self)
{
    (void) rm_check_destroyed(self);
    return magnify(False, self, MagnifyImage);
}

#magnify!Object


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# File 'ext/RMagick/rmimage.c', line 6118

VALUE
Image_magnify_bang(VALUE self)
{
    (void) rm_check_frozen(self);
    return magnify(True, self, MagnifyImage);
}

#map(*args) ⇒ Object

Method: Image#map(map_image, dither=false) Purpose: Call MapImage Returns: a new image


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# File 'ext/RMagick/rmimage.c', line 6131

VALUE
Image_map(int argc, VALUE *argv, VALUE self)
{
    Image *image, *new_image;
    Image *map;
    volatile VALUE map_obj, map_arg;
    unsigned int dither = MagickFalse;

    image = rm_check_destroyed(self);

#if defined(HAVE_REMAPIMAGE)
    rb_warning("Image#map is deprecated. Use Image#remap instead");
#endif

    switch (argc)
    {
        case 2:
            dither = RTEST(argv[1]);
        case 1:
            map_arg = argv[0];
            break;
        default:
            rb_raise(rb_eArgError, "wrong number of arguments (%d for 1 or 2)", argc);
            break;
    }

    new_image = rm_clone_image(image);

    map_obj = rm_cur_image(map_arg);
    map = rm_check_destroyed(map_obj);
    (void) MapImage(new_image, map, dither);
    rm_check_image_exception(new_image, DestroyOnError);

    return rm_image_new(new_image);
}

#marshal_dumpObject

Method: Image#marshal_dump Purpose: Support Marshal.dump >= 1.8 Returns: [img.filename, img.to_blob]


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# File 'ext/RMagick/rmimage.c', line 6173

VALUE
Image_marshal_dump(VALUE self)
{
    Image *image;
    Info *info;
    unsigned char *blob;
    size_t length;
    VALUE ary;
    ExceptionInfo exception;

    image = rm_check_destroyed(self);

    info = CloneImageInfo(NULL);
    if (!info)
    {
        rb_raise(rb_eNoMemError, "not enough memory to initialize Info object");
    }

    ary = rb_ary_new2(2);
    if (image->filename)
    {
        rb_ary_store(ary, 0, rb_str_new2(image->filename));
    }
    else
    {
        rb_ary_store(ary, 0, Qnil);
    }

    GetExceptionInfo(&exception);
    blob = ImageToBlob(info, image, &length, &exception);

    // Destroy info before raising an exception
    DestroyImageInfo(info);
    CHECK_EXCEPTION()
    (void) DestroyExceptionInfo(&exception);

    rb_ary_store(ary, 1, rb_str_new((char *)blob, (long)length));
    magick_free((void*)blob);

    return ary;
}

#marshal_load(ary) ⇒ Object

Method: Image#marshal_load Purpose: Support Marshal.load >= 1.8 Notes: On entry, ary is the array returned from marshal_dump.


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# File 'ext/RMagick/rmimage.c', line 6221

VALUE
Image_marshal_load(VALUE self, VALUE ary)
{
    VALUE blob, filename;
    Info *info;
    Image *image;
    ExceptionInfo exception;

    info = CloneImageInfo(NULL);
    if (!info)
    {
        rb_raise(rb_eNoMemError, "not enough memory to initialize Info object");
    }

    filename = rb_ary_shift(ary);
    blob = rb_ary_shift(ary);

    GetExceptionInfo(&exception);
    if (filename != Qnil)
    {
        strcpy(info->filename, RSTRING_PTR(filename));
    }
    image = BlobToImage(info, RSTRING_PTR(blob), RSTRING_LEN(blob), &exception);

    // Destroy info before raising an exception
    DestroyImageInfo(info);
    CHECK_EXCEPTION();
    (void) DestroyExceptionInfo(&exception);

    UPDATE_DATA_PTR(self, image);

    return self;
}

#mask(*args) ⇒ Object

Method: Image#mask() Purpose: associates a clip mask with the image Returns: Copy of the current clip-mask Notes: Omit the argument to get a copy of the current clip mask. Notes: pass “nil” for the mask-image to remove the current clip mask.

If the clip mask is not the same size as the target image,
resizes the clip mask to match the target.

Notes: Distinguish from Image#clip_mask=


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# File 'ext/RMagick/rmimage.c', line 6303

VALUE
Image_mask(int argc, VALUE *argv, VALUE self)
{
    volatile VALUE mask;
    Image *image, *mask_image, *resized_image;
    Image *clip_mask;
    long x, y;
    PixelPacket *q;
    ExceptionInfo exception;

    image = rm_check_destroyed(self);
    if (argc == 0)
    {
        return get_image_mask(image);
    }
    if (argc > 1)
    {
        rb_raise(rb_eArgError, "wrong number of arguments (expected 0 or 1, got %d)", argc);
    }

    rb_check_frozen(self);
    mask = argv[0];

    if (mask != Qnil)
    {
        mask = rm_cur_image(mask);
        mask_image = rm_check_destroyed(mask);
        clip_mask = rm_clone_image(mask_image);

        // Resize if necessary
        if (clip_mask->columns != image->columns || clip_mask->rows != image->rows)
        {
            GetExceptionInfo(&exception);
            resized_image = ResizeImage(clip_mask, image->columns, image->rows
                                        , UndefinedFilter, 0.0, &exception);
            rm_check_exception(&exception, resized_image, DestroyOnError);
            (void) DestroyExceptionInfo(&exception);
            rm_ensure_result(resized_image);
            (void) DestroyImage(clip_mask);
            clip_mask = resized_image;
        }

        // The following section is copied from mogrify.c (6.2.8-8)
#if defined(HAVE_SYNCAUTHENTICPIXELS)
        GetExceptionInfo(&exception);
#endif
        for (y = 0; y < (long) clip_mask->rows; y++)
        {
#if defined(HAVE_GETAUTHENTICPIXELS)
            q = GetAuthenticPixels(clip_mask, 0, y, clip_mask->columns, 1, &exception);
            rm_check_exception(&exception, clip_mask, DestroyOnError);
#else
            q = GetImagePixels(clip_mask, 0, y, clip_mask->columns, 1);
            rm_check_image_exception(clip_mask, DestroyOnError);
#endif
            if (!q)
            {
                break;
            }
            for (x = 0; x < (long) clip_mask->columns; x++)
            {
                if (clip_mask->matte == MagickFalse)
                {
                    q->opacity = PIXEL_INTENSITY(q);
                }
                q->red = q->opacity;
                q->green = q->opacity;
                q->blue = q->opacity;
                q += 1;
            }

#if defined(HAVE_SYNCAUTHENTICPIXELS)
            SyncAuthenticPixels(clip_mask, &exception);
            rm_check_exception(&exception, clip_mask, DestroyOnError);
#else
            SyncImagePixels(clip_mask);
            rm_check_image_exception(clip_mask, DestroyOnError);
#endif
        }
#if defined(HAVE_SYNCAUTHENTICPIXELS)
        (void) DestroyExceptionInfo(&exception);
#endif

        SetImageStorageClass(clip_mask, DirectClass);
        rm_check_image_exception(clip_mask, DestroyOnError);

        clip_mask->matte = MagickTrue;

        // SetImageClipMask clones the clip_mask image. We can
        // destroy our copy after SetImageClipMask is done with it.

        (void) SetImageClipMask(image, clip_mask);
        (void) DestroyImage(clip_mask);
    }
    else
    {
        (void) SetImageClipMask(image, NULL);
    }

    // Always return a copy of the mask!
    return get_image_mask(image);
}

#matte_fill_to_border(x, y) ⇒ Object

Make transparent any neighbor pixel that is not the border color.


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# File 'lib/RMagick.rb', line 948

def matte_fill_to_border(x, y)
    f = copy
    f.opacity = Magick::OpaqueOpacity unless f.matte
    f.matte_flood_fill(border_color, TransparentOpacity,
                       x, y, FillToBorderMethod)
end

#matte_flood_fill(color, opacity, x_obj, y_obj, method_obj) ⇒ Object

Method: Image#matte_flood_fill(color, opacity, x, y, method_obj) Purpose: Call MatteFloodFillImage


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# File 'ext/RMagick/rmimage.c', line 6479

VALUE
Image_matte_flood_fill(VALUE self, VALUE color, VALUE opacity, VALUE x_obj, VALUE y_obj, VALUE method_obj)
{
    Image *image, *new_image;
    PixelPacket target;
    Quantum op;
    long x, y;
    PaintMethod method;

    image = rm_check_destroyed(self);
    Color_to_PixelPacket(&target, color);

    op = APP2QUANTUM(opacity);

    VALUE_TO_ENUM(method_obj, method, PaintMethod);
    if (!(method == FloodfillMethod || method == FillToBorderMethod))
    {
        rb_raise(rb_eArgError, "paint method_obj must be FloodfillMethod or "
                 "FillToBorderMethod (%d given)", method);
    }
    x = NUM2LONG(x_obj);
    y = NUM2LONG(y_obj);
    if ((unsigned long)x > image->columns || (unsigned long)y > image->rows)
    {
        rb_raise(rb_eArgError, "target out of range. %ldx%ld given, image is %lux%lu"
                 , x, y, image->columns, image->rows);
    }


    new_image = rm_clone_image(image);

#if defined(HAVE_FLOODFILLPAINTIMAGE)
    {
        DrawInfo *draw_info;
        MagickPixelPacket target_mpp;
        MagickBooleanType invert;

        // FloodfillPaintImage looks for the opacity in the DrawInfo.fill field.
        draw_info = CloneDrawInfo(NULL, NULL);
        if (!draw_info)
        {
            rb_raise(rb_eNoMemError, "not enough memory to continue");
        }
        draw_info->fill.opacity = op;

        if (method == FillToBorderMethod)
        {
            invert = MagickTrue;
            target_mpp.red   = (MagickRealType) image->border_color.red;
            target_mpp.green = (MagickRealType) image->border_color.green;
            target_mpp.blue  = (MagickRealType) image->border_color.blue;
        }
        else
        {
            invert = MagickFalse;
            target_mpp.red   = (MagickRealType) target.red;
            target_mpp.green = (MagickRealType) target.green;
            target_mpp.blue  = (MagickRealType) target.blue;
        }

        (void) FloodfillPaintImage(new_image, OpacityChannel, draw_info, &target_mpp, x, y, invert);
    }
#else
    (void) MatteFloodfillImage(new_image, target, op, x, y, method);
#endif
    rm_check_image_exception(new_image, DestroyOnError);

    return rm_image_new(new_image);
}

#matte_floodfill(x, y) ⇒ Object

Make transparent any pixel that matches the color of the pixel at (x,y) and is a neighbor.


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# File 'lib/RMagick.rb', line 939

def matte_floodfill(x, y)
    f = copy
    f.opacity = OpaqueOpacity unless f.matte
    target = f.pixel_color(x, y)
    f.matte_flood_fill(target, TransparentOpacity,
                       x, y, FloodfillMethod)
end

#matte_point(x, y) ⇒ Object

Make the pixel at (x,y) transparent.


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# File 'lib/RMagick.rb', line 919

def matte_point(x, y)
    f = copy
    f.opacity = OpaqueOpacity unless f.matte
    pixel = f.pixel_color(x,y)
    pixel.opacity = TransparentOpacity
    f.pixel_color(x, y, pixel)
    return f
end

#matte_replace(x, y) ⇒ Object

Make transparent all pixels that are the same color as the pixel at (x, y).


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# File 'lib/RMagick.rb', line 930

def matte_replace(x, y)
    f = copy
    f.opacity = OpaqueOpacity unless f.matte
    target = f.pixel_color(x, y)
    f.transparent(target)
end

#matte_reset!Object

Make all pixels transparent.


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# File 'lib/RMagick.rb', line 956

def matte_reset!
    self.opacity = Magick::TransparentOpacity
    self
end

#median_filter(*args) ⇒ Object

Method: Image#median_filter(radius=0.0) Purpose: applies a digital filter that improves the quality of a noisy

image. Each pixel is replaced by the median in a set of
neighboring pixels as defined by radius.

Returns: a new image


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# File 'ext/RMagick/rmimage.c', line 6557

VALUE
Image_median_filter(int argc, VALUE *argv, VALUE self)
{
    Image *image, *new_image;
    double radius = 0.0;
    ExceptionInfo exception;

    image = rm_check_destroyed(self);
    switch (argc)
    {
        case 1:
            radius = NUM2DBL(argv[0]);
        case 0:
            break;
        default:
            rb_raise(rb_eArgError, "wrong number of arguments (%d for 0 or 1)", argc);
            break;
    }

    GetExceptionInfo(&exception);

    new_image = MedianFilterImage(image, radius, &exception);
    rm_check_exception(&exception, new_image, DestroyOnError);

    (void) DestroyExceptionInfo(&exception);

    rm_ensure_result(new_image);

    return rm_image_new(new_image);
}

#minifyObject

Method: Image#minify

Image#minify!

Purpose: Scales an image proportionally to half its size Returns: minify: a new image 1/2x the size of the input image

minify!: self, 1/2x

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# File 'ext/RMagick/rmimage.c', line 6626

VALUE
Image_minify(VALUE self)
{
    (void) rm_check_destroyed(self);
    return magnify(False, self, MinifyImage);
}

#minify!Object


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# File 'ext/RMagick/rmimage.c', line 6634

VALUE
Image_minify_bang(VALUE self)
{
    (void) rm_check_frozen(self);
    return magnify(True, self, MinifyImage);
}

#modulate(*args) ⇒ Object

Method: Image#modulate(<brightness<, saturation<, hue>>>) Purpose: control the brightness, saturation, and hue of an image Notes: all three arguments are optional and default to 100%


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# File 'ext/RMagick/rmimage.c', line 6647

VALUE
Image_modulate(int argc, VALUE *argv, VALUE self)
{
    Image *image, *new_image;
    double pct_brightness = 100.0,
    pct_saturation = 100.0,
    pct_hue        = 100.0;
    char modulate[100];

    image = rm_check_destroyed(self);
    switch (argc)
    {
        case 3:
            pct_hue        = 100*NUM2DBL(argv[2]);
        case 2:
            pct_saturation = 100*NUM2DBL(argv[1]);
        case 1:
            pct_brightness = 100*NUM2DBL(argv[0]);
            break;
        case 0:
            break;
        default:
            rb_raise(rb_eArgError, "wrong number of arguments (%d for 0 to 3)", argc);
            break;
    }

    if (pct_brightness <= 0.0)
    {
        rb_raise(rb_eArgError, "brightness is %g%%, must be positive", pct_brightness);
    }
    sprintf(modulate, "%f%%,%f%%,%f%%", pct_brightness, pct_saturation, pct_hue);

    new_image = rm_clone_image(image);

    (void) ModulateImage(new_image, modulate);
    rm_check_image_exception(new_image, DestroyOnError);

    return rm_image_new(new_image);
}

#monochrome?Boolean

Method: Image#monochrome? Purpose: return true if all the pixels in the image have the same red,

green, and blue intensities and the intensity is either 0 or
QuantumRange.

Returns:

  • (Boolean)

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# File 'ext/RMagick/rmimage.c', line 6721

VALUE
Image_monochrome_q(VALUE self)
{
    return has_attribute(self, (MagickBooleanType (*)(const Image *, ExceptionInfo *))IsMonochromeImage);
}

#motion_blur(*args) ⇒ Object

Method: Image#motion_blur(radius=0.0, sigma=1.0, angle=0.0) Purpose: simulates motion blur. Convolves the image with a Gaussian

operator of the given radius and standard deviation (sigma).
For reasonable results, radius should be larger than sigma.
Use a radius of 0 and motion_blur selects a suitable radius
for you. Angle gives the angle of the blurring motion.

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# File 'ext/RMagick/rmimage.c', line 6792

VALUE
Image_motion_blur(int argc, VALUE *argv, VALUE self)
{
    (void) rm_check_destroyed(self);
    return motion_blur(argc, argv, self, MotionBlurImage);
}

#negate(*args) ⇒ Object

Method: Image#negate(grayscale=false) Purpose: negates the colors in the reference image. The grayscale option

means that only grayscale values within the image are negated.

Notes: The default for grayscale is false.


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# File 'ext/RMagick/rmimage.c', line 6807

VALUE
Image_negate(int argc, VALUE *argv, VALUE self)
{
    Image *image, *new_image;
    unsigned int grayscale = MagickFalse;

    image = rm_check_destroyed(self);
    if (argc == 1)
    {
        grayscale = RTEST(argv[0]);
    }
    else if (argc > 1)
    {
        rb_raise(rb_eArgError, "wrong number of arguments (%d for 0 or 1)", argc);
    }

    new_image = rm_clone_image(image);

    (void) NegateImage(new_image, grayscale);
    rm_check_image_exception(new_image, DestroyOnError);

    return rm_image_new(new_image);
}

#negate_channel(*args) ⇒ Object

Method: Image#negate_channel(grayscale=false, channel=AllChannels) Returns a new image


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# File 'ext/RMagick/rmimage.c', line 6836

VALUE
Image_negate_channel(int argc, VALUE *argv, VALUE self)
{
    Image *image, *new_image;
    ChannelType channels;
    unsigned int grayscale = MagickFalse;

    image = rm_check_destroyed(self);
    channels = extract_channels(&argc, argv);

    // There can be at most 1 remaining argument.
    if (argc > 1)
    {
        raise_ChannelType_error(argv[argc-1]);
    }
    else if (argc == 1)
    {
        grayscale = RTEST(argv[0]);
    }

    Data_Get_Struct(self, Image, image);

    new_image = rm_clone_image(image);

    (void)NegateImageChannel(new_image, channels, grayscale);
    rm_check_image_exception(new_image, DestroyOnError);

    return rm_image_new(new_image);
}

#normalizeObject

Method: Image#normalize Purpose: enhances the contrast of a color image by adjusting the pixels

color to span the entire range of colors available

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# File 'ext/RMagick/rmimage.c', line 6969

VALUE
Image_normalize(VALUE self)
{
    Image *image, *new_image;

    image = rm_check_destroyed(self);
    new_image = rm_clone_image(image);

    (void) NormalizeImage(new_image);
    rm_check_image_exception(new_image, DestroyOnError);

    return rm_image_new(new_image);
}

#normalize_channel(*args) ⇒ Object

Method: Image#normalize_channel(channel=AllChannels) Purpose: Call NormalizeImageChannel


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# File 'ext/RMagick/rmimage.c', line 6988

VALUE
Image_normalize_channel(int argc, VALUE *argv, VALUE self)
{
    Image *image, *new_image;
    ChannelType channels;

    image = rm_check_destroyed(self);
    channels = extract_channels(&argc, argv);
    // Ensure all arguments consumed.
    if (argc > 0)
    {
        raise_ChannelType_error(argv[argc-1]);
    }

    new_image = rm_clone_image(image);

    (void) NormalizeImageChannel(new_image, channels);
    rm_check_image_exception(new_image, DestroyOnError);

    return rm_image_new(new_image);
}

#oil_paintObject

#opaque(target, fill) ⇒ Object

Method: Image#opaque(target-color-name, fill-color-name)

Image#opaque(target-pixel, fill-pixel)

Purpose: changes any pixel that matches target with the color defined by fill Notes: By default a pixel must match the specified target color exactly.

Use image.fuzz to set the amount of tolerance acceptable to consider
two colors as the same.

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# File 'ext/RMagick/rmimage.c', line 7085

VALUE
Image_opaque(VALUE self, VALUE target, VALUE fill)
{
    Image *image, *new_image;
    MagickPixelPacket target_pp;
    MagickPixelPacket fill_pp;
    MagickBooleanType okay;

    image = rm_check_destroyed(self);
    new_image = rm_clone_image(image);

    // Allow color name or Pixel
    Color_to_MagickPixelPacket(image, &target_pp, target);
    Color_to_MagickPixelPacket(image, &fill_pp, fill);

#if defined(HAVE_OPAQUEPAINTIMAGECHANNEL)
    okay = OpaquePaintImageChannel(new_image, DefaultChannels, &target_pp, &fill_pp, MagickFalse);
#else
    okay =  PaintOpaqueImageChannel(new_image, DefaultChannels, &target_pp, &fill_pp);
#endif
    rm_check_image_exception(new_image, DestroyOnError);

    if (!okay)
    {
        // Force exception
        DestroyImage(new_image);
        rm_ensure_result(NULL);
    }

    return rm_image_new(new_image);
}

#opaque?Boolean

Method: Image#opaque? Purpose: return true if any of the pixels in the image have an opacity

value other than opaque ( 0 )

Returns:

  • (Boolean)

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# File 'ext/RMagick/rmimage.c', line 7197

VALUE
Image_opaque_q(VALUE self)
{
    return has_attribute(self, IsOpaqueImage);
}

#opaque_channel(*args) ⇒ Object

Method: Image#opaque_channel Purpose: Improved Image#opaque available in 6.3.7-10 Notes: opaque_channel(target, fill, invert=false, fuzz=img.fuzz [, channel…])


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# File 'ext/RMagick/rmimage.c', line 7123

VALUE
Image_opaque_channel(int argc, VALUE *argv, VALUE self)
{
#if defined(HAVE_OPAQUEPAINTIMAGECHANNEL)
    Image *image, *new_image;
    MagickPixelPacket target_pp, fill_pp;
    ChannelType channels;
    double keep, fuzz;
    MagickBooleanType okay, invert = MagickFalse;

    image = rm_check_destroyed(self);
    channels = extract_channels(&argc, argv);
    if (argc > 4)
    {
        raise_ChannelType_error(argv[argc-1]);
    }

    // Default fuzz value is image's fuzz attribute.
    fuzz = image->fuzz;

    switch (argc)
    {
        case 4:
            fuzz = NUM2DBL(argv[3]);
            if (fuzz < 0.0)
            {
                rb_raise(rb_eArgError, "fuzz must be >= 0.0 (%g given)", fuzz);
            }
        case 3:
            invert = RTEST(argv[2]);
        case 2:
            // Allow color name or Pixel
            Color_to_MagickPixelPacket(image, &fill_pp, argv[1]);
            Color_to_MagickPixelPacket(image, &target_pp, argv[0]);
            break;
        default:
            rb_raise(rb_eArgError, "wrong number of arguments (got %d, expected 2 or more)", argc);
            break;
    }

    new_image = rm_clone_image(image);
    keep = new_image->fuzz;
    new_image->fuzz = fuzz;

    okay = OpaquePaintImageChannel(new_image, channels, &target_pp, &fill_pp, invert);

    // Restore saved fuzz value
    new_image->fuzz = keep;
    rm_check_image_exception(new_image, DestroyOnError);

    if (!okay)
    {
        // Force exception
        DestroyImage(new_image);
        rm_ensure_result(NULL);
    }

    return rm_image_new(new_image);

#else
    argc = argc;    // defeat "unused parameter" messages
    argv = argv;
    self = self;
    rm_not_implemented();
    return(VALUE)0;
#endif
}

#ordered_dither(*args) ⇒ Object

Method: Image#ordered_dither(threshold_map='2x2') Purpose: perform ordered dither on image Notes: order must be 2, 3, or 4

(6.3.0) order can be any of the threshold strings listed
by "convert -list Thresholds" but the default is still "2x2".
I don't call OrderedDitherImages anymore. Sometime after
IM 6.0.0 it quit working. IM and GM use the routines I use
below to implement the "ordered-dither" option.

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# File 'ext/RMagick/rmimage.c', line 7214

VALUE
Image_ordered_dither(int argc, VALUE *argv, VALUE self)
{
    Image *image, *new_image;
    int order;
    const char *threshold_map = "2x2";
    ExceptionInfo exception;

    image = rm_check_destroyed(self);

    if (argc > 1)
    {
        rb_raise(rb_eArgError, "wrong number of arguments (%d for 0 or 1)", argc);
    }
    if (argc == 1)
    {
        if (TYPE(argv[0]) == T_STRING)
        {
            threshold_map = StringValuePtr(argv[0]);
        }
        else
        {
            order = NUM2INT(argv[0]);
            if (order == 3)
            {
                threshold_map = "3x3";
            }
            else if (order == 4)
            {
                threshold_map = "4x4";
            }
            else if (order != 2)
            {
                rb_raise(rb_eArgError, "order must be 2, 3, or 4 (%d given)", order);
            }
        }
    }

    new_image = rm_clone_image(image);

    GetExceptionInfo(&exception);

    // ImageMagick >= 6.2.9
    (void) OrderedPosterizeImage(new_image, threshold_map, &exception);
    rm_check_exception(&exception, new_image, DestroyOnError);

    (void) DestroyExceptionInfo(&exception);

    return rm_image_new(new_image);
}

#paint_transparent(*args) ⇒ Object

Method: Image#paint_transparent(target, opacity=TransparentOpacity, invert=false, fuzz=img.fuzz) Purpose: Improved version of Image#transparent available in 6.3.7-10


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# File 'ext/RMagick/rmimage.c', line 7320

VALUE
Image_paint_transparent(int argc, VALUE *argv, VALUE self)
{
#if defined(HAVE_TRANSPARENTPAINTIMAGE)
    Image *image, *new_image;
    MagickPixelPacket color;
    Quantum opacity = TransparentOpacity;
    double keep, fuzz;
    MagickBooleanType okay, invert = MagickFalse;

    image = rm_check_destroyed(self);

    // Default fuzz value is image's fuzz attribute.
    fuzz = image->fuzz;

    switch (argc)
    {
        case 4:
            fuzz = NUM2DBL(argv[3]);
        case 3:
            invert = RTEST(argv[2]);
        case 2:
            opacity = APP2QUANTUM(argv[1]);
        case 1:
            Color_to_MagickPixelPacket(image, &color, argv[0]);
            break;
        default:
            rb_raise(rb_eArgError, "wrong number of arguments (%d for 1 to 4)", argc);
            break;
    }

    new_image = rm_clone_image(image);

    // Use fuzz value from caller
    keep = new_image->fuzz;
    new_image->fuzz = fuzz;

    okay = TransparentPaintImage(new_image, (const MagickPixelPacket *)&color, opacity, invert);
    new_image->fuzz = keep;

    // Is it possible for TransparentPaintImage to silently fail?
    rm_check_image_exception(new_image, DestroyOnError);
    if (!okay)
    {
        // Force exception
        DestroyImage(new_image);
        rm_ensure_result(NULL);
    }

    return rm_image_new(new_image);
#else
    argc = argc;    // defeat "unused parameter" messages
    argv = argv;
    self = self;
    rm_not_implemented();
    return(VALUE)0;
#endif
}

#palette?Boolean

Method: Image#palette? Purpose: return true if the image is PseudoClass and has 256 unique

colors or less.

Returns:

  • (Boolean)

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# File 'ext/RMagick/rmimage.c', line 7385

VALUE
Image_palette_q(VALUE self)
{
    return has_attribute(self, IsPaletteImage);
}

#pixel_color(*args) ⇒ Object

Method: Image#pixel_color(x, y<, color>) Purpose: Gets/sets the color of the pixel at x,y Returns: Magick::Pixel for pixel x,y. If called to set a new

color, the return value is the old color.

Notes: “color”, if present, may be either a color name or a

Magick::Pixel.
Based on Magick++'s Magick::pixelColor methods

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# File 'ext/RMagick/rmimage.c', line 7414

VALUE
Image_pixel_color(int argc, VALUE *argv, VALUE self)
{
    Image *image;
    PixelPacket old_color, new_color, *pixel;
    ExceptionInfo exception;
    long x, y;
    unsigned int set = False;
    MagickBooleanType okay;

    memset(&old_color, 0, sizeof(old_color));

    image = rm_check_destroyed(self);

    switch (argc)
    {
        case 3:
            rb_check_frozen(self);
            set = True;
            // Replace with new color? The arg can be either a color name or
            // a Magick::Pixel.
            Color_to_PixelPacket(&new_color, argv[2]);
        case 2:
            break;
        default:
            rb_raise(rb_eArgError, "wrong number of arguments (%d for 2 or 3)", argc);
            break;
    }

    x = NUM2LONG(argv[0]);
    y = NUM2LONG(argv[1]);

    // Get the color of a pixel
    if (!set)
    {
        GetExceptionInfo(&exception);
#if defined(HAVE_GETVIRTUALPIXELS)
        old_color = *GetVirtualPixels(image, x, y, 1, 1, &exception);
#else
        old_color = *AcquireImagePixels(image, x, y, 1, 1, &exception);
#endif
        CHECK_EXCEPTION()

        (void) DestroyExceptionInfo(&exception);

        // PseudoClass
        if (image->storage_class == PseudoClass)
        {
#if defined(HAVE_GETAUTHENTICINDEXQUEUE)
            IndexPacket *indexes = GetAuthenticIndexQueue(image);
#else
            IndexPacket *indexes = GetIndexes(image);
#endif
            old_color = image->colormap[*indexes];
        }
        if (!image->matte)
        {
            old_color.opacity = OpaqueOpacity;
        }
        return Pixel_from_PixelPacket(&old_color);
    }

    // ImageMagick segfaults if the pixel location is out of bounds.
    // Do what IM does and return the background color.
    if (x < 0 || y < 0 || (unsigned long)x >= image->columns || (unsigned long)y >= image->rows)
    {
        return Pixel_from_PixelPacket(&image->background_color);
    }

    // Set the color of a pixel. Return previous color.
    // Convert to DirectClass
    if (image->storage_class == PseudoClass)
    {
        okay = SetImageStorageClass(image, DirectClass);
        rm_check_image_exception(image, RetainOnError);
        if (!okay)
        {
            rb_raise(Class_ImageMagickError, "SetImageStorageClass failed. Can't set pixel color.");
        }
    }


#if defined(HAVE_GETAUTHENTICPIXELS) || defined(HAVE_SYNCAUTHENTICPIXELS)
    GetExceptionInfo(&exception);
#endif

#if defined(HAVE_GETAUTHENTICPIXELS)
    pixel = GetAuthenticPixels(image, x, y, 1, 1, &exception);
    CHECK_EXCEPTION()
#else
    pixel = GetImagePixels(image, x, y, 1, 1);
    rm_check_image_exception(image, RetainOnError);
#endif

    if (pixel)
    {
        old_color = *pixel;
        if (!image->matte)
        {
            old_color.opacity = OpaqueOpacity;
        }
    }
    *pixel = new_color;

#if defined(HAVE_SYNCAUTHENTICPIXELS)
    SyncAuthenticPixels(image, &exception);
    CHECK_EXCEPTION()
#else
    SyncImagePixels(image);
    rm_check_image_exception(image, RetainOnError);
#endif

#if defined(HAVE_GETAUTHENTICPIXELS) || defined(HAVE_SYNCAUTHENTICPIXELS)
    (void) DestroyExceptionInfo(&exception);
#endif

    return Pixel_from_PixelPacket(&old_color);
}

#polaroid(*args) ⇒ Object

Method: Image#polaroid() Purpose: Call PolaroidImage Notes: Accepts an options block to get Draw attributes for drawing

the label. Specify self.border_color to set a non-default
border color.

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# File 'ext/RMagick/rmimage.c', line 7564

VALUE
Image_polaroid(int argc, VALUE *argv, VALUE self)
{
    Image *image, *clone, *new_image;
    volatile VALUE options;
    double angle = -5.0;
    Draw *draw;
    ExceptionInfo exception;

    image = rm_check_destroyed(self);

    switch (argc)
    {
        case 1:
            angle = NUM2DBL(argv[0]);
        case 0:
            break;
        default:
            rb_raise(rb_eArgError, "wrong number of arguments (%d for 0 or 1)", argc);
            break;
    }

    options = rm_polaroid_new();
    Data_Get_Struct(options, Draw, draw);

    clone = rm_clone_image(image);
    clone->background_color = draw->shadow_color;
    clone->border_color = draw->info->border_color;

    GetExceptionInfo(&exception);
    new_image = PolaroidImage(clone, draw->info, angle, &exception);
    rm_check_exception(&exception, clone, DestroyOnError);

    (void) DestroyImage(clone);
    (void) DestroyExceptionInfo(&exception);

    rm_ensure_result(new_image);

    return rm_image_new(new_image);
}

#posterize(*args) ⇒ Object

Method: posterize Purpose: call PosterizeImage Notes: Image#posterize(levels=4, dither=false)


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# File 'ext/RMagick/rmimage.c', line 7611

VALUE
Image_posterize(int argc, VALUE *argv, VALUE self)
{
    Image *image, *new_image;
    MagickBooleanType dither = MagickFalse;
    unsigned long levels = 4;

    image = rm_check_destroyed(self);
    switch (argc)
    {
        case 2:
            dither = (MagickBooleanType) RTEST(argv[1]);
            /* fall through */
        case 1:
            levels = NUM2ULONG(argv[0]);
            /* fall through */
        case 0:
            break;
        default:
            rb_raise(rb_eArgError, "wrong number of arguments (%d for 0 to 2)", argc);
    }

    new_image = rm_clone_image(image);

    (void) PosterizeImage(new_image, levels, dither);
    rm_check_image_exception(new_image, DestroyOnError);

    return rm_image_new(new_image);
}

#preview(preview) ⇒ Object

Method: preview Purpose: Call PreviewImage


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# File 'ext/RMagick/rmimage.c', line 7646

VALUE
Image_preview(VALUE self, VALUE preview)
{
    Image *image, *new_image;
    PreviewType preview_type;
    ExceptionInfo exception;

    GetExceptionInfo(&exception);
    image = rm_check_destroyed(self);
    VALUE_TO_ENUM(preview, preview_type, PreviewType);

    new_image = PreviewImage(image, preview_type, &exception);
    rm_check_exception(&exception, new_image, DestroyOnError);

    (void) DestroyExceptionInfo(&exception);

    rm_ensure_result(new_image);

    return rm_image_new(new_image);
}

#profile!(name, profile) ⇒ Object

Method: Image#profile!(name, profile) Purpose: If “profile” is nil, deletes the profile. Otherwise “profile”

must be a string containing the specified profile.

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# File 'ext/RMagick/rmimage.c', line 7673

VALUE
Image_profile_bang(VALUE self, VALUE name, VALUE profile)
{

    if (profile == Qnil)
    {
        return Image_delete_profile(self, name);
    }
    else
    {
        return set_profile(self, StringValuePtr(name), profile);
    }

}

#propertiesObject

Method: Image#properties [{ |k,v| block }] Purpose: Traverse the attributes and yield to the block.

If no block, return a hash of all the attribute
keys & values

Notes: I use the word “properties” to distinguish between

these "user-added" attribute strings and Image
object attributes.

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# File 'ext/RMagick/rmimage.c', line 8915

VALUE
Image_properties(VALUE self)
{
    Image *image;
    volatile VALUE attr_hash;
    volatile VALUE ary;
    char *property;
    const char *value;

    image = rm_check_destroyed(self);

    if (rb_block_given_p())
    {
        ary = rb_ary_new2(2);

        ResetImagePropertyIterator(image);
        property = GetNextImageProperty(image);
        while (property)
        {
            value = GetImageProperty(image, property);
            (void) rb_ary_store(ary, 0, rb_str_new2(property));
            (void) rb_ary_store(ary, 1, rb_str_new2(value));
            (void) rb_yield(ary);
            property = GetNextImageProperty(image);
        }
        rm_check_image_exception(image, RetainOnError);
        return self;
    }

    // otherwise return properties hash
    else
    {
        attr_hash = rb_hash_new();
        ResetImagePropertyIterator(image);
        property = GetNextImageProperty(image);
        while (property)
        {
            value = GetImageProperty(image, property);
            (void) rb_hash_aset(attr_hash, rb_str_new2(property), rb_str_new2(value));
            property = GetNextImageProperty(image);
        }
        rm_check_image_exception(image, RetainOnError);
        return attr_hash;
    }

}

#quantize(*args) ⇒ Object

Method: Image#quantize(<number_colors<, colorspace<, dither<, tree_depth<, measure_error>>>>>)

defaults: 256, Magick::RGBColorspace, true, 0, false

Purpose: call QuantizeImage


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# File 'ext/RMagick/rmimage.c', line 7885

VALUE
Image_quantize(int argc, VALUE *argv, VALUE self)
{
    Image *image, *new_image;
    QuantizeInfo quantize_info;

    image = rm_check_destroyed(self);
    GetQuantizeInfo(&quantize_info);

    switch (argc)
    {
        case 5:
            quantize_info.measure_error = (MagickBooleanType) RTEST(argv[4]);
        case 4:
            quantize_info.tree_depth = NUM2UINT(argv[3]);
        case 3:
#if defined(HAVE_TYPE_DITHERMETHOD) && defined(HAVE_ENUM_NODITHERMETHOD)
            if (rb_obj_is_kind_of(argv[2], Class_DitherMethod))
            {
                VALUE_TO_ENUM(argv[2], quantize_info.dither_method, DitherMethod);
                quantize_info.dither = quantize_info.dither_method != NoDitherMethod;
            }
#else
            quantize_info.dither = (MagickBooleanType) RTEST(argv[2]);
#endif
        case 2:
            VALUE_TO_ENUM(argv[1], quantize_info.colorspace, ColorspaceType);
        case 1:
            quantize_info.number_colors = NUM2UINT(argv[0]);
        case 0:
            break;
        default:
            rb_raise(rb_eArgError, "wrong number of arguments (%d for 0 to 5)", argc);
            break;
    }

    new_image = rm_clone_image(image);

    (void) QuantizeImage(&quantize_info, new_image);
    rm_check_image_exception(new_image, DestroyOnError);

    return rm_image_new(new_image);
}

#quantum_operator(*args) ⇒ Object

Method: Image#quantum_operator(operator, rvalue[, channel] ) Purpose: This method is an adapter method that calls the

EvaluateImageChannel method

Note 1: Historically this method used QuantumOperatorRegionImage

in GraphicsMagick. By necessity this method implements
the "lowest common denominator" of the two implementations.

Note 2: If the channel argument is omitted, the default is AllChannels.


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# File 'ext/RMagick/rmimage.c', line 7724

VALUE
Image_quantum_operator(int argc, VALUE *argv, VALUE self)
{
    Image *image;
    QuantumExpressionOperator operator;
    MagickEvaluateOperator qop;
    double rvalue;
    ChannelType channel;
    ExceptionInfo exception;

    image = rm_check_destroyed(self);

    // The default channel is AllChannels
    channel = AllChannels;

    /*
        If there are 3 arguments, argument 2 is a ChannelType argument.
        Arguments 1 and 0 are required and are the rvalue and operator,
        respectively.
    */
    switch (argc)
    {
        case 3:
            VALUE_TO_ENUM(argv[2], channel, ChannelType);
            /* Fall through */
        case 2:
            rvalue = NUM2DBL(argv[1]);
            VALUE_TO_ENUM(argv[0], operator, QuantumExpressionOperator);
            break;
        default:
            rb_raise(rb_eArgError, "wrong number of arguments (%d for 2 or 3)", argc);
            break;
    }

    // Map QuantumExpressionOperator to MagickEvaluateOperator
    switch (operator)
    {
        default:
        case UndefinedQuantumOperator:
            qop = UndefinedEvaluateOperator;
            break;
        case AddQuantumOperator:
            qop = AddEvaluateOperator;
            break;
        case AndQuantumOperator:
            qop = AndEvaluateOperator;
            break;
        case DivideQuantumOperator:
            qop = DivideEvaluateOperator;
            break;
        case LShiftQuantumOperator:
            qop = LeftShiftEvaluateOperator;
            break;
        case MaxQuantumOperator:
            qop = MaxEvaluateOperator;
            break;
        case MinQuantumOperator:
            qop = MinEvaluateOperator;
            break;
        case MultiplyQuantumOperator:
            qop = MultiplyEvaluateOperator;
            break;
        case OrQuantumOperator:
            qop = OrEvaluateOperator;
            break;
        case RShiftQuantumOperator:
            qop = RightShiftEvaluateOperator;
            break;
        case SubtractQuantumOperator:
            qop = SubtractEvaluateOperator;
            break;
        case XorQuantumOperator:
            qop = XorEvaluateOperator;
            break;
#if defined(HAVE_ENUM_POWEVALUATEOPERATOR)
        case PowQuantumOperator:
            qop = PowEvaluateOperator;
            break;
#endif
#if defined(HAVE_ENUM_LOGEVALUATEOPERATOR)
        case LogQuantumOperator:
            qop = LogEvaluateOperator;
            break;
#endif
#if defined(HAVE_ENUM_THRESHOLDEVALUATEOPERATOR)
        case ThresholdQuantumOperator:
            qop = ThresholdEvaluateOperator;
            break;
#endif
#if defined(HAVE_ENUM_THRESHOLDBLACKEVALUATEOPERATOR)
        case ThresholdBlackQuantumOperator:
            qop = ThresholdBlackEvaluateOperator;
            break;
#endif
#if defined(HAVE_ENUM_THRESHOLDWHITEEVALUATEOPERATOR)
        case ThresholdWhiteQuantumOperator:
            qop = ThresholdWhiteEvaluateOperator;
            break;
#endif
#if defined(HAVE_ENUM_GAUSSIANNOISEEVALUATEOPERATOR)
        case GaussianNoiseQuantumOperator:
            qop = GaussianNoiseEvaluateOperator;
            break;
#endif
#if defined(HAVE_ENUM_IMPULSENOISEEVALUATEOPERATOR)
        case ImpulseNoiseQuantumOperator:
            qop = ImpulseNoiseEvaluateOperator;
            break;
#endif
#if defined(HAVE_ENUM_LAPLACIANNOISEEVALUATEOPERATOR)
        case LaplacianNoiseQuantumOperator:
            qop = LaplacianNoiseEvaluateOperator;
            break;
#endif
#if defined(HAVE_ENUM_MULTIPLICATIVENOISEEVALUATEOPERATOR)
        case MultiplicativeNoiseQuantumOperator:
            qop = MultiplicativeNoiseEvaluateOperator;
            break;
#endif
#if defined(HAVE_ENUM_POISSONNOISEEVALUATEOPERATOR)
        case PoissonNoiseQuantumOperator:
            qop = PoissonNoiseEvaluateOperator;
            break;
#endif
#if defined(HAVE_ENUM_UNIFORMNOISEEVALUATEOPERATOR)
        case UniformNoiseQuantumOperator:
            qop = UniformNoiseEvaluateOperator;
            break;
#endif
#if defined(HAVE_ENUM_COSINEEVALUATEOPERATOR)
        case CosineQuantumOperator:
            qop = CosineEvaluateOperator;
            break;
#endif
#if defined(HAVE_ENUM_SINEEVALUATEOPERATOR)
        case SineQuantumOperator:
            qop = SineEvaluateOperator;
            break;
#endif
#if defined(HAVE_ENUM_ADDMODULUSEVALUATEOPERATOR)
        case AddModulusQuantumOperator:
            qop = AddModulusEvaluateOperator;
            break;
#endif
    }

    GetExceptionInfo(&exception);
    (void) EvaluateImageChannel(image, channel, qop, rvalue, &exception);
    CHECK_EXCEPTION()

    (void) DestroyExceptionInfo(&exception);

    return self;
}

#radial_blur(angle) ⇒ Object

Method: Image#radial_blur(angle) Purpose: Call RadialBlurImage Notes: Angle is in degrees


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# File 'ext/RMagick/rmimage.c', line 7935

VALUE
Image_radial_blur(VALUE self, VALUE angle)
{
    Image *image, *new_image;
    ExceptionInfo exception;

    image = rm_check_destroyed(self);
    GetExceptionInfo(&exception);

    new_image = RadialBlurImage(image, NUM2DBL(angle), &exception);
    rm_check_exception(&exception, new_image, DestroyOnError);

    (void) DestroyExceptionInfo(&exception);

    rm_ensure_result(new_image);

    return rm_image_new(new_image);
}

#radial_blur_channel(*args) ⇒ Object

Method: Image#radial_blur_channel(angle[, channel..]) Purpose: Call RadialBlurImageChannel Notes: Angle is in degrees


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# File 'ext/RMagick/rmimage.c', line 7960

VALUE
Image_radial_blur_channel(
                         int argc,
                         VALUE *argv,
                         VALUE self)
{
    Image *image, *new_image;
    ExceptionInfo exception;
    ChannelType channels;

    image = rm_check_destroyed(self);
    channels = extract_channels(&argc, argv);

    // There must be 1 remaining argument.
    if (argc == 0)
    {
        rb_raise(rb_eArgError, "wrong number of arguments (0 for 1 or more)");
    }
    else if (argc > 1)
    {
        raise_ChannelType_error(argv[argc-1]);
    }

    GetExceptionInfo(&exception);

    new_image = RadialBlurImageChannel(image, channels, NUM2DBL(argv[0]), &exception);

    rm_check_exception(&exception, new_image, DestroyOnError);
    (void) DestroyExceptionInfo(&exception);
    rm_ensure_result(new_image);

    return rm_image_new(new_image);
}

#raise(*args) ⇒ Object

Method: Image#raise(width=6, height=6, raised=true) Purpose: creates a simulated three-dimensional button-like effect by

lightening and darkening the edges of the image. The "width"
and "height" arguments define the width of the vertical and
horizontal edge of the effect. If "raised" is true, creates
a raised effect, otherwise a lowered effect.

Returns: a new image


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# File 'ext/RMagick/rmimage.c', line 8048

VALUE
Image_raise(int argc, VALUE *argv, VALUE self)
{
    Image *image, *new_image;
    RectangleInfo rect;
    int raised = MagickTrue;      // default

    memset(&rect, 0, sizeof(rect));
    rect.width = 6;         // default
    rect.height = 6;        // default

    image = rm_check_destroyed(self);
    switch (argc)
    {
        case 3:
            raised = RTEST(argv[2]);
        case 2:
            rect.height = NUM2ULONG(argv[1]);
        case 1:
            rect.width = NUM2ULONG(argv[0]);
        case 0:
            break;
        default:
            rb_raise(rb_eArgError, "wrong number of arguments (%d for 0 to 3)", argc);
            break;
    }

    new_image = rm_clone_image(image);

    (void) RaiseImage(new_image, &rect, raised);
    rm_check_image_exception(new_image, DestroyOnError);

    return rm_image_new(new_image);
}

#random_threshold_channel(*args) ⇒ Object

Method: Image#random_threshold_channel PUrpose: Call RandomThresholdImageChannel


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# File 'ext/RMagick/rmimage.c', line 7999

VALUE
Image_random_threshold_channel(int argc, VALUE *argv, VALUE self)
{
    Image *image, *new_image;
    ChannelType channels;
    char *thresholds;
    volatile VALUE geom_str;
    ExceptionInfo exception;

    image = rm_check_destroyed(self);

    channels = extract_channels(&argc, argv);

    // There must be 1 remaining argument.
    if (argc == 0)
    {
        rb_raise(rb_eArgError, "missing threshold argument");
    }
    else if (argc > 1)
    {
        raise_ChannelType_error(argv[argc-1]);
    }

    // Accept any argument that has a to_s method.
    geom_str = rm_to_s(argv[0]);
    thresholds = StringValuePtr(geom_str);

    new_image = rm_clone_image(image);

    GetExceptionInfo(&exception);

    (void) RandomThresholdImageChannel(new_image, channels, thresholds, &exception);
    rm_check_exception(&exception, new_image, DestroyOnError);

    (void) DestroyExceptionInfo(&exception);

    return rm_image_new(new_image);
}

#recolor(color_matrix) ⇒ Object

Method: Image#recolor(matrix) Purpose: Call RecolorImage


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# File 'ext/RMagick/rmimage.c', line 8168

VALUE
Image_recolor(VALUE self, VALUE color_matrix)
{
    Image *image, *new_image;
    unsigned long order;
    long x, len;
    double *matrix;
    ExceptionInfo exception;

    image = rm_check_destroyed(self);
    GetExceptionInfo(&exception);

    // Allocate color matrix from Ruby's memory
    len = RARRAY_LEN(color_matrix);
    matrix = ALLOC_N(double, len);

    for (x = 0; x < len; x++)
    {
        matrix[x] = NUM2DBL(rb_ary_entry(color_matrix, x));
    }

    order = (unsigned long)sqrt((double)(len + 1.0));

    // RecolorImage sets the ExceptionInfo and returns a NULL image if an error occurs.
    new_image = RecolorImage(image, order, matrix, &exception);
    xfree((void *)matrix);

    rm_check_exception(&exception, new_image, DestroyOnError);
    (void) DestroyExceptionInfo(&exception);

    return rm_image_new(new_image);
}

#reduce_noise(radius) ⇒ Object

Method: Image#reduce_noise(radius) Purpose: smooths the contours of an image while still preserving edge information Returns: a new image


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# File 'ext/RMagick/rmimage.c', line 8295

VALUE
Image_reduce_noise(VALUE self, VALUE radius)
{
    Image *image, *new_image;
    ExceptionInfo exception;

    image = rm_check_destroyed(self);

    GetExceptionInfo(&exception);
    new_image = ReduceNoiseImage(image, NUM2DBL(radius), &exception);
    rm_check_exception(&exception, new_image, DestroyOnError);

    (void) DestroyExceptionInfo(&exception);

    return rm_image_new(new_image);
}

#remap(*args) ⇒ Object Also known as: affinity

Method: Image#remap(remap_image, dither_method=RiemersmaDitherMethod) Purpose: Call RemapImage Notes: Immediate - modifies image in-place


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# File 'ext/RMagick/rmimage.c', line 8318

VALUE
Image_remap(int argc, VALUE *argv, VALUE self)
{
#if defined(HAVE_REMAPIMAGE) || defined(HAVE_AFFINITYIMAGE)
    Image *image, *remap_image;
    QuantizeInfo quantize_info;

    image = rm_check_frozen(self);
    if (argc > 0)
    {
        volatile VALUE t = rm_cur_image(argv[0]);
        remap_image = rm_check_destroyed(t);
    }

    GetQuantizeInfo(&quantize_info);

    switch (argc)
    {
        case 2:
            VALUE_TO_ENUM(argv[1], quantize_info.dither_method, DitherMethod);
            quantize_info.dither = MagickTrue;
            break;
        case 1:
            break;
        default:
            rb_raise(rb_eArgError, "wrong number of arguments (%d for 1 or 2)", argc);
            break;
    }

#if defined(HAVE_REMAPIMAGE)
    (void) RemapImage(&quantize_info, image, remap_image);
#else
    (void) AffinityImage(&quantize_info, image, remap_image);
#endif
    rm_check_image_exception(image, RetainOnError);

    return self;
#else
    self = self;
    argc = argc;
    argv = argv;
    rm_not_implemented();
    return(VALUE)0;
#endif
}

#resample(x_res = 72.0, y_res = nil) ⇒ Object

Corresponds to ImageMagick's -resample option


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# File 'lib/RMagick.rb', line 962

def resample(x_res=72.0, y_res=nil)
    y_res ||= x_res
    width = x_res * columns / x_resolution + 0.5
    height = y_res * rows / y_resolution + 0.5
    self.x_resolution = x_res
    self.y_resolution = y_res
    resize(width, height)
end

#resize(*args) ⇒ Object


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# File 'ext/RMagick/rmimage.c', line 8470

VALUE
Image_resize(int argc, VALUE *argv, VALUE self)
{
    (void) rm_check_destroyed(self);
    return resize(False, argc, argv, self);
}

#resize!(*args) ⇒ Object


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# File 'ext/RMagick/rmimage.c', line 8478

VALUE
Image_resize_bang(int argc, VALUE *argv, VALUE self)
{
    (void) rm_check_frozen(self);
    return resize(True, argc, argv, self);
}

#resize_to_fill(ncols, nrows = nil, gravity = CenterGravity) ⇒ Object Also known as: crop_resized

Force an image to exact dimensions without changing the aspect ratio. Resize and crop if necessary. (Thanks to Jerett Taylor!)


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# File 'lib/RMagick.rb', line 973

def resize_to_fill(ncols, nrows=nil, gravity=CenterGravity)
    copy.resize_to_fill!(ncols, nrows, gravity)
end

#resize_to_fill!(ncols, nrows = nil, gravity = CenterGravity) ⇒ Object Also known as: crop_resized!


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# File 'lib/RMagick.rb', line 977

def resize_to_fill!(ncols, nrows=nil, gravity=CenterGravity)
    nrows ||= ncols
    if ncols != columns || nrows != rows
        scale = [ncols/columns.to_f, nrows/rows.to_f].max
        resize!(scale*columns+0.5, scale*rows+0.5)
    end
    crop!(gravity, ncols, nrows, true) if ncols != columns || nrows != rows
    self
end

#resize_to_fit(cols, rows = nil) ⇒ Object

Convenience method to resize retaining the aspect ratio. (Thanks to Robert Manni!)


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# File 'lib/RMagick.rb', line 993

def resize_to_fit(cols, rows=nil)
    rows ||= cols
    change_geometry(Geometry.new(cols, rows)) do |ncols, nrows|
        resize(ncols, nrows)
    end
end

#resize_to_fit!(cols, rows = nil) ⇒ Object


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# File 'lib/RMagick.rb', line 1000

def resize_to_fit!(cols, rows=nil)
    rows ||= cols
    change_geometry(Geometry.new(cols, rows)) do |ncols, nrows|
        resize!(ncols, nrows)
    end
end

#roll(x_offset, y_offset) ⇒ Object

Method: Image#roll(x_offset, y_offset) Purpose: offsets an image as defined by x_offset and y_offset Returns: a rolled copy of the input image


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# File 'ext/RMagick/rmimage.c', line 8491

VALUE
Image_roll(VALUE self, VALUE x_offset, VALUE y_offset)
{
    Image *image, *new_image;
    ExceptionInfo exception;

    image = rm_check_destroyed(self);

    GetExceptionInfo(&exception);
    new_image = RollImage(image, NUM2LONG(x_offset), NUM2LONG(y_offset), &exception);
    rm_check_exception(&exception, new_image, DestroyOnError);

    (void) DestroyExceptionInfo(&exception);

    rm_ensure_result(new_image);

    return rm_image_new(new_image);
}

#rotate(*args) ⇒ Object


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# File 'ext/RMagick/rmimage.c', line 8573

VALUE
Image_rotate(int argc, VALUE *argv, VALUE self)
{
    (void) rm_check_destroyed(self);
    return rotate(False, argc, argv, self);
}

#rotate!(*args) ⇒ Object


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# File 'ext/RMagick/rmimage.c', line 8581

VALUE
Image_rotate_bang(int argc, VALUE *argv, VALUE self)
{
    (void) rm_check_frozen(self);
    return rotate(True, argc, argv, self);
}

#sampleObject

#sample!(*args) ⇒ Object


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# File 'ext/RMagick/rmimage.c', line 8607

VALUE
Image_sample_bang(int argc, VALUE *argv, VALUE self)
{
    (void) rm_check_frozen(self);
    return scale(True, argc, argv, self, SampleImage);
}

#scale(*args) ⇒ Object

Method: Image#scale(scale) or (cols, rows)

Image#scale!

Purpose: changes the size of an image to the given dimensions Returns: scale: a scaled copy of the input image

scale!: self, scaled

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# File 'ext/RMagick/rmimage.c', line 8622

VALUE
Image_scale(int argc, VALUE *argv, VALUE self)
{
    (void) rm_check_destroyed(self);
    return scale(False, argc, argv, self, ScaleImage);
}

#scale!(*args) ⇒ Object


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# File 'ext/RMagick/rmimage.c', line 8630

VALUE
Image_scale_bang(int argc, VALUE *argv, VALUE self)
{
    (void) rm_check_frozen(self);
    return scale(True, argc, argv, self, ScaleImage);
}

#segment(*args) ⇒ Object

Method: Image#segment(colorspace=RGBColorspace,

cluster_threshold=1.0,
smoothing_threshold=1.5,
verbose=false)

Purpose: Call SegmentImage Notes: the default values are the same as Magick++


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# File 'ext/RMagick/rmimage.c', line 8851

VALUE
Image_segment(int argc, VALUE *argv, VALUE self)
{
    Image *image, *new_image;
    int colorspace              = RGBColorspace;    // These are the Magick++ defaults
    unsigned int verbose        = MagickFalse;
    double cluster_threshold    = 1.0;
    double smoothing_threshold  = 1.5;

    image = rm_check_destroyed(self);
    switch (argc)
    {
        case 4:
            verbose = RTEST(argv[3]);
        case 3:
            smoothing_threshold = NUM2DBL(argv[2]);
        case 2:
            cluster_threshold = NUM2DBL(argv[1]);
        case 1:
            VALUE_TO_ENUM(argv[0], colorspace, ColorspaceType);
        case 0:
            break;
        default:
            rb_raise(rb_eArgError, "wrong number of arguments (%d for 0 to 4)", argc);
            break;
    }

    new_image = rm_clone_image(image);

    (void) SegmentImage(new_image, colorspace, verbose, cluster_threshold, smoothing_threshold);
    rm_check_image_exception(new_image, DestroyOnError);
    rm_ensure_result(new_image);

    return rm_image_new(new_image);
}

#selective_blur_channelObject

#separate(*args) ⇒ Object

Method: separate(channel[, channel…]) Purpose: call SeparateImages Returns: returns a new ImageList


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# File 'ext/RMagick/rmimage.c', line 8782

VALUE
Image_separate(int argc, VALUE *argv, VALUE self)
{
    Image *image, *new_images;
    ChannelType channels = 0;
    ExceptionInfo exception;

    image = rm_check_destroyed(self);
    channels = extract_channels(&argc, argv);

    // All arguments are ChannelType enums
    if (argc > 0)
    {
        raise_ChannelType_error(argv[argc-1]);
    }

    GetExceptionInfo(&exception);
    new_images = SeparateImages(image, channels, &exception);
    rm_check_exception(&exception, new_images, DestroyOnError);
    DestroyExceptionInfo(&exception);
    rm_ensure_result(new_images);

    return rm_imagelist_from_images(new_images);
}

#sepiatone(*args) ⇒ Object

Method: Image#sepiatone(threshold=QuantumRange) Purpose: Call SepiaToneImage


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# File 'ext/RMagick/rmimage.c', line 8812

VALUE
Image_sepiatone(int argc, VALUE *argv, VALUE self)
{
    Image *image, *new_image;
    double threshold = (double) QuantumRange;
    ExceptionInfo exception;

    image = rm_check_destroyed(self);

    switch (argc)
    {
        case 1:
            threshold = NUM2DBL(argv[0]);
            break;
        case 0:
            break;
        default:
            rb_raise(rb_eArgError, "wrong number of arguments (%d for 0 or 1)", argc);
    }

    GetExceptionInfo(&exception);
    new_image = SepiaToneImage(image, threshold, &exception);
    rm_check_exception(&exception, new_image, DestroyOnError);

    (void) DestroyExceptionInfo(&exception);
    rm_ensure_result(new_image);

    return rm_image_new(new_image);
}

#set_channel_depth(channel_arg, depth) ⇒ Object

Method: Image#set_channel_depth(channel, depth) Purpose: Call SetImageChannelDepth


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# File 'ext/RMagick/rmimage.c', line 8758

VALUE
Image_set_channel_depth(VALUE self, VALUE channel_arg, VALUE depth)
{
    Image *image;
    ChannelType channel;
    unsigned long channel_depth;

    image = rm_check_frozen(self);

    VALUE_TO_ENUM(channel_arg, channel, ChannelType);
    channel_depth = NUM2ULONG(depth);

    (void) SetImageChannelDepth(image, channel, channel_depth);
    rm_check_image_exception(image, RetainOnError);

    return self;
}

#shade(*args) ⇒ Object

Method: Image#shade(shading=false, azimuth=30, elevation=30) Purpose: shines a distant light on an image to create a three-dimensional

effect. You control the positioning of the light with azimuth
and elevation; azimuth is measured in degrees off the x axis
and elevation is measured in pixels above the Z axis

Returns: a new image


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# File 'ext/RMagick/rmimage.c', line 8971

VALUE
Image_shade(int argc, VALUE *argv, VALUE self)
{
    Image *image, *new_image;
    double azimuth = 30.0, elevation = 30.0;
    unsigned int shading=MagickFalse;
    ExceptionInfo exception;

    image = rm_check_destroyed(self);
    switch (argc)
    {
        case 3:
            elevation = NUM2DBL(argv[2]);
        case 2:
            azimuth = NUM2DBL(argv[1]);
        case 1:
            shading = RTEST(argv[0]);
        case 0:
            break;
        default:
            rb_raise(rb_eArgError, "wrong number of arguments (%d for 0 to 3)", argc);
            break;
    }

    GetExceptionInfo(&exception);
    new_image = ShadeImage(image, shading, azimuth, elevation, &exception);
    rm_check_exception(&exception, new_image, DestroyOnError);

    (void) DestroyExceptionInfo(&exception);
    rm_ensure_result(new_image);

    return rm_image_new(new_image);
}

#shadow(*args) ⇒ Object

Method: Image#shadow(x_offset=4, y_offset=4, sigma=4.0, opacity=1.0)

x- and y-offsets are the pixel offset
opacity is either a number between 0 and 1 or a string "NN%"
sigma is the std. dev. of the Gaussian, in pixels.

Purpose: Call ShadowImage Notes: The defaults are taken from the mogrify.c source, except

for opacity, which has no default.
Introduced in 6.1.7

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# File 'ext/RMagick/rmimage.c', line 9016

VALUE
Image_shadow(int argc, VALUE *argv, VALUE self)
{
    Image *image, *new_image;
    double opacity = 100.0;
    double sigma = 4.0;
    long x_offset = 4L;
    long y_offset = 4L;
    ExceptionInfo exception;

    image = rm_check_destroyed(self);
    switch (argc)
    {
        case 4:
            opacity = rm_percentage(argv[3]);   // Clamp to 1.0 < x <= 100.0
            if (fabs(opacity) < 0.01)
            {
                rb_warning("shadow will be transparent - opacity %g very small", opacity);
            }
            opacity = FMIN(opacity, 1.0);
            opacity = FMAX(opacity, 0.01);
            opacity *= 100.0;
        case 3:
            sigma = NUM2DBL(argv[2]);
        case 2:
            y_offset = NUM2LONG(argv[1]);
        case 1:
            x_offset = NUM2LONG(argv[0]);
        case 0:
            break;
        default:
            rb_raise(rb_eArgError, "wrong number of arguments (%d for 0 to 4)", argc);
            break;
    }

    GetExceptionInfo(&exception);
    new_image = ShadowImage(image, opacity, sigma, x_offset, y_offset, &exception);
    rm_check_exception(&exception, new_image, DestroyOnError);

    (void) DestroyExceptionInfo(&exception);
    rm_ensure_result(new_image);

    return rm_image_new(new_image);
}

#sharpen(*args) ⇒ Object

Method: Image#sharpen(radius=0, sigma=1) Purpose: sharpens an image Returns: a new image


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# File 'ext/RMagick/rmimage.c', line 9067

VALUE
Image_sharpen(int argc, VALUE *argv, VALUE self)
{
    return effect_image(self, argc, argv, SharpenImage);
}

#sharpen_channel(*args) ⇒ Object

Method: Image#sharpen_channel(radius=0, sigma=1, channel=AllChannels) Returns: a new image


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# File 'ext/RMagick/rmimage.c', line 9078

VALUE
Image_sharpen_channel(int argc, VALUE *argv, VALUE self)
{
    Image *image, *new_image;
    ChannelType channels;
    ExceptionInfo exception;
    double radius = 0.0, sigma = 1.0;

    image = rm_check_destroyed(self);
    channels = extract_channels(&argc, argv);

    // There must be 0, 1, or 2 remaining arguments.
    switch (argc)
    {
        case 2:
            sigma = NUM2DBL(argv[1]);
            /* Fall thru */
        case 1:
            radius = NUM2DBL(argv[0]);
            /* Fall thru */
        case 0:
            break;
        default:
            raise_ChannelType_error(argv[argc-1]);
    }

    new_image = rm_clone_image(image);

    GetExceptionInfo(&exception);
    (void) SharpenImageChannel(new_image, channels, radius, sigma, &exception);

    rm_check_exception(&exception, new_image, DestroyOnError);
    (void) DestroyExceptionInfo(&exception);

    return rm_image_new(new_image);
}

#shave(width, height) ⇒ Object

Method: Image#shave(width, height)

Image#shave!(width, height)

Purpose: shaves pixels from the image edges, leaving a rectangle

of the specified width & height in the center

Returns: shave: a new image

shave!: self, shaved

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# File 'ext/RMagick/rmimage.c', line 9124

VALUE
Image_shave(VALUE self, VALUE width, VALUE height)
{
    (void) rm_check_destroyed(self);
    return xform_image(False, self, INT2FIX(0), INT2FIX(0), width, height, ShaveImage);
}

#shave!(width, height) ⇒ Object


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# File 'ext/RMagick/rmimage.c', line 9132

VALUE
Image_shave_bang(VALUE self, VALUE width, VALUE height)
{
    (void) rm_check_frozen(self);
    return xform_image(True, self, INT2FIX(0), INT2FIX(0), width, height, ShaveImage);
}

#shear(x_shear, y_shear) ⇒ Object

Method: Image#shear(x_shear, y_shear) Purpose: Calls ShearImage Notes: shear angles are measured in degrees Returns: a new image


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# File 'ext/RMagick/rmimage.c', line 9146

VALUE
Image_shear(VALUE self, VALUE x_shear, VALUE y_shear)
{
    Image *image, *new_image;
    ExceptionInfo exception;

    image = rm_check_destroyed(self);

    GetExceptionInfo(&exception);
    new_image = ShearImage(image, NUM2DBL(x_shear), NUM2DBL(y_shear), &exception);
    rm_check_exception(&exception, new_image, DestroyOnError);

    (void) DestroyExceptionInfo(&exception);
    rm_ensure_result(new_image);

    return rm_image_new(new_image);
}

#sigmoidal_contrast_channel(*args) ⇒ Object

Method: Image#sigmoidal_contrast_channel(contrast=3.0, midpoint=50.0,

sharpen=false [, channel=AllChannels]);

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# File 'ext/RMagick/rmimage.c', line 9169

VALUE
Image_sigmoidal_contrast_channel(int argc, VALUE *argv, VALUE self)
{
    Image *image, *new_image;
    MagickBooleanType sharpen = MagickFalse;
    double contrast = 3.0;
    double midpoint = 50.0;
    ChannelType channels;

    image = rm_check_destroyed(self);
    channels = extract_channels(&argc, argv);

    switch (argc)
    {
        case 3:
            sharpen  = (MagickBooleanType) RTEST(argv[2]);
        case 2:
            midpoint = NUM2DBL(argv[1]);
        case 1:
            contrast = NUM2DBL(argv[0]);
        case 0:
            break;
        default:
            raise_ChannelType_error(argv[argc-1]);
            break;
    }

    new_image = rm_clone_image(image);

    (void) SigmoidalContrastImageChannel(new_image, channels, sharpen, contrast, midpoint);
    rm_check_image_exception(new_image, DestroyOnError);

    return rm_image_new(new_image);
}

#signatureObject

Method: Image#signature Purpose: computes a message digest from an image pixel stream with an

implementation of the NIST SHA-256 Message Digest algorithm.

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# File 'ext/RMagick/rmimage.c', line 9210

VALUE
Image_signature(VALUE self)
{
    Image *image;
    const char *signature;

    image = rm_check_destroyed(self);

    (void) SignatureImage(image);
    signature = rm_get_property(image, "signature");
    rm_check_image_exception(image, RetainOnError);
    if (!signature)
    {
        return Qnil;
    }
    return rb_str_new(signature, 64);
}

#sketch(*args) ⇒ Object

Method: Image#sketch(radius=0.0, sigma=1.0, angle=0.0) Purpose: Call SketchImage


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# File 'ext/RMagick/rmimage.c', line 9233

VALUE
Image_sketch(int argc, VALUE *argv, VALUE self)
{
    (void) rm_check_destroyed(self);
    return motion_blur(argc, argv, self, SketchImage);
}

#solarize(*args) ⇒ Object

Method: Image#solarize(threshold=50.0) Purpose: applies a special effect to the image, similar to the effect

achieved in a photo darkroom by selectively exposing areas of
photo sensitive paper to light. Threshold ranges from 0 to
QuantumRange and is a measure of the extent of the solarization.

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# File 'ext/RMagick/rmimage.c', line 9248

VALUE
Image_solarize(int argc, VALUE *argv, VALUE self)
{
    Image *image, *new_image;
    double threshold = 50.0;

    image = rm_check_destroyed(self);
    switch (argc)
    {
        case 1:
            threshold = NUM2DBL(argv[0]);
            if (threshold < 0.0 || threshold > QuantumRange)
            {
                rb_raise(rb_eArgError, "threshold out of range, must be >= 0.0 and < QuantumRange");
            }
        case 0:
            break;
        default:
            rb_raise(rb_eArgError, "wrong number of arguments (%d for 0 or 1)", argc);
            break;
    }

    new_image = rm_clone_image(image);

    (void) SolarizeImage(new_image, threshold);
    rm_check_image_exception(new_image, DestroyOnError);

    return rm_image_new(new_image);
}

#sparse_color(*args) ⇒ Object


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# File 'ext/RMagick/rmimage.c', line 9363

VALUE
Image_sparse_color(int argc, VALUE *argv, VALUE self)
{
#if defined(HAVE_SPARSECOLORIMAGE)
    Image *image, *new_image;
    unsigned long x, nargs, ncolors;
    SparseColorMethod method;
    int n, exp;
    double * volatile args;
    ChannelType channels;
    MagickPixelPacket pp;
    ExceptionInfo exception;

    image = rm_check_destroyed(self);

    n = argc;
    channels = extract_channels(&argc, argv);
    n -= argc;  // n is now the number of channel arguments

    // After the channel arguments have been removed, and not counting the first
    // (method) argument, the number of arguments should be a multiple of 3.
    if (argc < 4 || argc % 3 != 1)
    {
        exp = argc - 1;
        exp = (argc + 2) / 3 * 3;
        exp = max(exp, 3);
        rb_raise(rb_eArgError, "wrong number of arguments (expected at least %d, got %d)", n+exp+1,  n+argc);
    }

    // Get the method from the argument list
    VALUE_TO_ENUM(argv[0], method, SparseColorMethod);
    argv += 1;
    argc -= 1;

    // A lot of the following code is based on SparseColorOption, in wand/mogrify.c
    ncolors = count_channels(image, &channels);
    nargs = (argc / 3) * (2 + ncolors);

    // Allocate args from Ruby's memory so that GC will collect it if one of
    // the type conversions below raises an exception.
    args = ALLOC_N(double, nargs);
    memset(args, 0, nargs * sizeof(double));

    x = 0;
    n = 0;
    while (n < argc)
    {
        args[x++] = NUM2DBL(argv[n++]);
        args[x++] = NUM2DBL(argv[n++]);
        Color_to_MagickPixelPacket(NULL, &pp, argv[n++]);
        if (channels & RedChannel)
        {
            args[x++] = pp.red / QuantumRange;
        }
        if (channels & GreenChannel)
        {
            args[x++] = pp.green / QuantumRange;
        }
        if (channels & BlueChannel)
        {
            args[x++] = pp.blue / QuantumRange;
        }
        if (channels & IndexChannel)
        {
            args[x++] = pp.index / QuantumRange;
        }
        if (channels & OpacityChannel)
        {
            args[x++] = pp.opacity / QuantumRange;
        }
    }

    GetExceptionInfo(&exception);
    new_image = SparseColorImage(image, channels, method, nargs, args, &exception);
    xfree(args);
    CHECK_EXCEPTION();
    rm_ensure_result(new_image);

    return rm_image_new(new_image);

#else
    self = self;
    argc = argc;
    argv = argv;
    rm_not_implemented();
    return(VALUE)0;
#endif
}

#splice(*args) ⇒ Object

Method: Image#splice(x, y, width, height[, color]) Purpose: Splice a solid color into the part of the image specified

by the x, y, width, and height arguments. If the color
argument is specified it must be a color name or Pixel.
If not specified uses the background color.

Notes: splice is the inverse of chop


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# File 'ext/RMagick/rmimage.c', line 9462

VALUE
Image_splice(int argc, VALUE *argv, VALUE self)
{
    Image *image, *new_image;
    PixelPacket color, old_color;
    RectangleInfo rectangle;
    ExceptionInfo exception;

    image = rm_check_destroyed(self);

    switch (argc)
    {
        case 4:
            // use background color
            color = image->background_color;
            break;
        case 5:
            // Convert color argument to PixelPacket
            Color_to_PixelPacket(&color, argv[4]);
            break;
        default:
            rb_raise(rb_eArgError, "wrong number of arguments (%d for 4 or 5)", argc);
            break;
    }

    rectangle.x      = NUM2LONG(argv[0]);
    rectangle.y      = NUM2LONG(argv[1]);
    rectangle.width  = NUM2ULONG(argv[2]);
    rectangle.height = NUM2ULONG(argv[3]);

    GetExceptionInfo(&exception);

    // Swap in color for the duration of this call.
    old_color = image->background_color;
    image->background_color = color;
    new_image = SpliceImage(image, &rectangle, &exception);
    image->background_color = old_color;

    rm_check_exception(&exception, new_image, DestroyOnError);

    (void) DestroyExceptionInfo(&exception);

    rm_ensure_result(new_image);

    return rm_image_new(new_image);
}

#spread(*args) ⇒ Object

Method: Image#spread(radius=3) Purpose: randomly displaces each pixel in a block defined by “radius” Returns: a new image


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# File 'ext/RMagick/rmimage.c', line 9515

VALUE
Image_spread(int argc, VALUE *argv, VALUE self)
{
    Image *image, *new_image;
    double radius = 3.0;
    ExceptionInfo exception;

    image = rm_check_destroyed(self);
    switch (argc)
    {
        case 1:
            radius = NUM2DBL(argv[0]);
        case 0:
            break;
        default:
            rb_raise(rb_eArgError, "wrong number of arguments (%d for 0 or 1)", argc);
            break;
    }

    GetExceptionInfo(&exception);
    new_image = SpreadImage(image, radius, &exception);
    rm_check_exception(&exception, new_image, DestroyOnError);
    rm_ensure_result(new_image);

    (void) DestroyExceptionInfo(&exception);

    return rm_image_new(new_image);
}

#steganoObject

#stereo(offset_image_arg) ⇒ Object

Method: Image#stereo(offset_image) Purpose: combines two images and produces a single image that is the

composite of a left and right image of a stereo pair.
Special red-green stereo glasses are required to view this
effect.

Returns: a new image


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# File 'ext/RMagick/rmimage.c', line 9591

VALUE
Image_stereo(VALUE self, VALUE offset_image_arg)
{
    Image *image, *new_image;
    volatile VALUE offset_image;
    Image *offset;
    ExceptionInfo exception;

    image = rm_check_destroyed(self);

    offset_image = rm_cur_image(offset_image_arg);
    offset = rm_check_destroyed(offset_image);

    GetExceptionInfo(&exception);
    new_image = StereoImage(image, offset, &exception);
    rm_check_exception(&exception, new_image, DestroyOnError);

    (void) DestroyExceptionInfo(&exception);

    rm_ensure_result(new_image);

    return rm_image_new(new_image);
}

#store_pixels(x_arg, y_arg, cols_arg, rows_arg, new_pixels) ⇒ Object

Method: Image#store_pixels Purpose: Replace the pixels in the specified rectangle Notes: Calls GetImagePixels, then SyncImagePixels after replacing

the pixels. This is the complement of get_pixels. The array
object returned by get_pixels is suitable for use as the
"new_pixels" argument.

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# File 'ext/RMagick/rmimage.c', line 9671

VALUE
Image_store_pixels(VALUE self, VALUE x_arg, VALUE y_arg, VALUE cols_arg
                   , VALUE rows_arg, VALUE new_pixels)
{
    Image *image;
    Pixel *pixels, *pixel;
    volatile VALUE new_pixel;
    long n, size;
    long x, y;
    unsigned long cols, rows;
    unsigned int okay;

    image = rm_check_destroyed(self);

    x = NUM2LONG(x_arg);
    y = NUM2LONG(y_arg);
    cols = NUM2ULONG(cols_arg);
    rows = NUM2ULONG(rows_arg);
    if (x < 0 || y < 0 || x+cols > image->columns || y+rows > image->rows)
    {
        rb_raise(rb_eRangeError, "geometry (%lux%lu%+ld%+ld) exceeds image bounds"
                 , cols, rows, x, y);
    }

    size = (long)(cols * rows);
    rm_check_ary_len(new_pixels, size);

    okay = SetImageStorageClass(image, DirectClass);
    rm_check_image_exception(image, RetainOnError);
    if (!okay)
    {
        rb_raise(Class_ImageMagickError, "SetImageStorageClass failed. Can't store pixels.");
    }

    // Get a pointer to the pixels. Replace the values with the PixelPackets
    // from the pixels argument.
    {
#if defined(HAVE_SYNCAUTHENTICPIXELS) || defined(HAVE_GETAUTHENTICPIXELS)
        ExceptionInfo exception;
        GetExceptionInfo(&exception);
#endif

#if defined(HAVE_GETAUTHENTICPIXELS)
        pixels = GetAuthenticPixels(image, x, y, cols, rows, &exception);
        CHECK_EXCEPTION()
#else
        pixels = GetImagePixels(image, x, y, cols, rows);
        rm_check_image_exception(image, RetainOnError);
#endif

        if (pixels)
        {
            for (n = 0; n < size; n++)
            {
                new_pixel = rb_ary_entry(new_pixels, n);
                Data_Get_Struct(new_pixel, Pixel, pixel);
                pixels[n] = *pixel;
            }
#if defined(HAVE_SYNCAUTHENTICPIXELS)
            SyncAuthenticPixels(image, &exception);
            CHECK_EXCEPTION()
#else
            SyncImagePixels(image);
            rm_check_image_exception(image, RetainOnError);
#endif
        }

#if defined(HAVE_SYNCAUTHENTICPIXELS) || defined(HAVE_GETAUTHENTICPIXELS)
        DestroyExceptionInfo(&exception);
#endif
    }

    return self;
}

#strip!Object

Method: Image#strip! Purpose: strips an image of all profiles and comments.


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# File 'ext/RMagick/rmimage.c', line 9751

VALUE
Image_strip_bang(VALUE self)
{
    Image *image = rm_check_frozen(self);
    (void) StripImage(image);
    rm_check_image_exception(image, RetainOnError);
    return self;
}

#swirl(degrees) ⇒ Object

Method: Image#swirl(degrees) Purpose: swirls the pixels about the center of the image, where degrees

indicates the sweep of the arc through which each pixel is moved.
You get a more dramatic effect as the degrees move from 1 to 360.

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# File 'ext/RMagick/rmimage.c', line 9767

VALUE
Image_swirl(VALUE self, VALUE degrees)
{
    Image *image, *new_image;
    ExceptionInfo exception;

    image = rm_check_destroyed(self);

    GetExceptionInfo(&exception);
    new_image = SwirlImage(image, NUM2DBL(degrees), &exception);
    rm_check_exception(&exception, new_image, DestroyOnError);

    (void) DestroyExceptionInfo(&exception);

    rm_ensure_result(new_image);

    return rm_image_new(new_image);
}

#sync_profilesObject

Method: Image#sync_profiles() Purpose: synchronizes image properties with the image profiles


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# File 'ext/RMagick/rmimage.c', line 9791

VALUE
Image_sync_profiles(VALUE self)
{
    Image *image = rm_check_destroyed(self);
    volatile VALUE okay =  SyncImageProfiles(image) ? Qtrue : Qfalse;
    rm_check_image_exception(image, RetainOnError);
    return okay;
}

#texture_fill_to_border(x, y, texture) ⇒ Object

Replace neighboring pixels to border color with texture pixels


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# File 'lib/RMagick.rb', line 1014

def texture_fill_to_border(x, y, texture)
    texture_flood_fill(border_color, texture, x, y, FillToBorderMethod)
end

#texture_flood_fill(color_obj, texture_obj, x_obj, y_obj, method_obj) ⇒ Object

Method: Image#texture_flood_fill(color, texture, x, y, method) Purpose: Emulates Magick++'s floodFillTexture

If the FloodfillMethod method is specified, flood-fills
texture across pixels starting at the target pixel and
matching the specified color.

If the FillToBorderMethod method is specified, flood-fills
"texture across pixels starting at the target pixel and
stopping at pixels matching the specified color."

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# File 'ext/RMagick/rmimage.c', line 9812

VALUE
Image_texture_flood_fill(VALUE self, VALUE color_obj, VALUE texture_obj
                         , VALUE x_obj, VALUE y_obj, VALUE method_obj)
{
    Image *image, *new_image;
    Image *texture_image;
    PixelPacket color;
    volatile VALUE texture;
    DrawInfo *draw_info;
    long x, y;
    PaintMethod method;

    image = rm_check_destroyed(self);

    Color_to_PixelPacket(&color, color_obj);
    texture = rm_cur_image(texture_obj);
    texture_image = rm_check_destroyed(texture);

    x = NUM2LONG(x_obj);
    y = NUM2LONG(y_obj);

    if ((unsigned long)x > image->columns || (unsigned long)y > image->rows)
    {
        rb_raise(rb_eArgError, "target out of range. %ldx%ld given, image is %lux%lu"
                 , x, y, image->columns, image->rows);
    }

    VALUE_TO_ENUM(method_obj, method, PaintMethod);
    if (method != FillToBorderMethod && method != FloodfillMethod)
    {
        rb_raise(rb_eArgError, "paint method must be FloodfillMethod or "
                 "FillToBorderMethod (%d given)", (int)method);
    }

    draw_info = CloneDrawInfo(NULL, NULL);
    if (!draw_info)
    {
        rb_raise(rb_eNoMemError, "not enough memory to continue");
    }

    draw_info->fill_pattern = rm_clone_image(texture_image);
    new_image = rm_clone_image(image);


#if defined(HAVE_FLOODFILLPAINTIMAGE)
    {
        MagickPixelPacket color_mpp;
        MagickBooleanType invert;

        GetMagickPixelPacket(new_image, &color_mpp);
        if (method == FillToBorderMethod)
        {
            invert = MagickTrue;
            color_mpp.red   = (MagickRealType) image->border_color.red;
            color_mpp.green = (MagickRealType) image->border_color.green;
            color_mpp.blue  = (MagickRealType) image->border_color.blue;
        }
        else
        {
            invert = MagickFalse;
            color_mpp.red   = (MagickRealType) color.red;
            color_mpp.green = (MagickRealType) color.green;
            color_mpp.blue  = (MagickRealType) color.blue;
        }

        (void) FloodfillPaintImage(new_image, DefaultChannels, draw_info, &color_mpp, x, y, invert);
    }

#else
    (void) ColorFloodfillImage(new_image, draw_info, color, x, y, method);
#endif

    (void) DestroyDrawInfo(draw_info);
    rm_check_image_exception(new_image, DestroyOnError);


    return rm_image_new(new_image);
}

#texture_floodfill(x, y, texture) ⇒ Object

Replace matching neighboring pixels with texture pixels


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# File 'lib/RMagick.rb', line 1008

def texture_floodfill(x, y, texture)
    target = pixel_color(x, y)
    texture_flood_fill(target, texture, x, y, FloodfillMethod)
end

#threshold(threshold) ⇒ Object

Method: Image#threshold(threshold) Purpose: changes the value of individual pixels based on the intensity of

each pixel compared to threshold. The result is a high-contrast,
two color image.

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# File 'ext/RMagick/rmimage.c', line 9898

VALUE
Image_threshold(VALUE self, VALUE threshold)
{
    Image *image, *new_image;

    image = rm_check_destroyed(self);
    new_image = rm_clone_image(image);

    (void) ThresholdImage(new_image, NUM2DBL(threshold));
    rm_check_image_exception(new_image, DestroyOnError);

    return rm_image_new(new_image);
}

#thumbnail(*args) ⇒ Object


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# File 'ext/RMagick/rmimage.c', line 10029

VALUE
Image_thumbnail(int argc, VALUE *argv, VALUE self)
{
    (void) rm_check_destroyed(self);
    return thumbnail(False, argc, argv, self);
}

#thumbnail!(*args) ⇒ Object


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# File 'ext/RMagick/rmimage.c', line 10037

VALUE
Image_thumbnail_bang(int argc, VALUE *argv, VALUE self)
{
    (void) rm_check_frozen(self);
    return thumbnail(True, argc, argv, self);
}

#tint(*args) ⇒ Object

Method: Image#tint Purpose: Call TintImage Notes: Opacity values are percentages: 0.10 -> 10%.


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# File 'ext/RMagick/rmimage.c', line 10071

VALUE
Image_tint(int argc, VALUE *argv, VALUE self)
{
    Image *image, *new_image;
    Pixel *tint;
    double red_pct_opaque, green_pct_opaque, blue_pct_opaque;
    double alpha_pct_opaque = 1.0;
    char opacity[50];
    ExceptionInfo exception;

    image = rm_check_destroyed(self);

    switch (argc)
    {
        case 2:
            red_pct_opaque   = NUM2DBL(argv[1]);
            green_pct_opaque = blue_pct_opaque = red_pct_opaque;
            break;
        case 3:
            red_pct_opaque   = NUM2DBL(argv[1]);
            green_pct_opaque = NUM2DBL(argv[2]);
            blue_pct_opaque  = red_pct_opaque;
            break;
        case 4:
            red_pct_opaque     = NUM2DBL(argv[1]);
            green_pct_opaque   = NUM2DBL(argv[2]);
            blue_pct_opaque    = NUM2DBL(argv[3]);
            break;
        case 5:
            red_pct_opaque     = NUM2DBL(argv[1]);
            green_pct_opaque   = NUM2DBL(argv[2]);
            blue_pct_opaque    = NUM2DBL(argv[3]);
            alpha_pct_opaque   = NUM2DBL(argv[4]);
            break;
        default:
            rb_raise(rb_eArgError, "wrong number of arguments (%d for 2 to 5)", argc);
            break;
    }

    if (red_pct_opaque < 0.0 || green_pct_opaque < 0.0
        || blue_pct_opaque < 0.0 || alpha_pct_opaque < 0.0)
    {
        rb_raise(rb_eArgError, "opacity percentages must be non-negative.");
    }

#if defined(HAVE_SNPRINTF)
    snprintf(opacity, sizeof(opacity),
#else
    sprintf(opacity,
#endif
            "%g,%g,%g,%g", red_pct_opaque*100.0, green_pct_opaque*100.0
            , blue_pct_opaque*100.0, alpha_pct_opaque*100.0);

    Data_Get_Struct(argv[0], Pixel, tint);
    GetExceptionInfo(&exception);

    new_image = TintImage(image, opacity, *tint, &exception);
    rm_check_exception(&exception, new_image, DestroyOnError);

    (void) DestroyExceptionInfo(&exception);

    rm_ensure_result(new_image);

    return rm_image_new(new_image);
}


/*
    Method:     Image#to_blob
    Purpose:    Return a "blob" (a String) from the image
    Notes:      The magick member of the Image structure
                determines the format of the returned blob
                (GIG, JPEG,  PNG, etc.)
*/
VALUE
Image_to_blob(VALUE self)
{
    Image *image;
    Info *info;
    const MagickInfo *magick_info;
    volatile VALUE info_obj;
    volatile VALUE blob_str;
    void *blob = NULL;
    size_t length = 2048;       // Do what Magick++ does
    ExceptionInfo exception;

    // The user can specify the depth (8 or 16, if the format supports
    // both) and the image format by setting the depth and format
    // values in the info parm block.
    info_obj = rm_info_new();
    Data_Get_Struct(info_obj, Info, info);

    image = rm_check_destroyed(self);

    // Copy the depth and magick fields to the Image
    if (info->depth != 0)
    {
        (void) SetImageDepth(image, info->depth);
        rm_check_image_exception(image, RetainOnError);
    }

    GetExceptionInfo(&exception);
    if (*info->magick)
    {
        (void) SetImageInfo(info, MagickTrue, &exception);
        CHECK_EXCEPTION()

        if (*info->magick == '\0')
        {
            return Qnil;
        }
        strncpy(image->magick, info->magick, sizeof(info->magick)-1);
    }

    // Fix #2844 - libjpeg exits when image is 0x0
    magick_info = GetMagickInfo(image->magick, &exception);
    CHECK_EXCEPTION()

    if (magick_info)
    {
        if (  (!rm_strcasecmp(magick_info->name, "JPEG")
               || !rm_strcasecmp(magick_info->name, "JPG"))
              && (image->rows == 0 || image->columns == 0))
        {
            rb_raise(rb_eRuntimeError, "Can't convert %lux%lu %.4s image to a blob"
                     , image->columns, image->rows, magick_info->name);
        }
    }

    rm_sync_image_options(image, info);

    blob = ImageToBlob(info, image, &length, &exception);
    CHECK_EXCEPTION()

    (void) DestroyExceptionInfo(&exception);

    if (length == 0 || !blob)
    {
        return Qnil;
    }

    blob_str = rb_str_new(blob, length);

    magick_free((void*)blob);

    return blob_str;
}


/*
    Method:     Image#to_color
    Purpose:    Return a color name for the color intensity specified by the
                Magick::Pixel argument.
    Notes:      Respects depth and matte attributes
*/
VALUE
Image_to_color(VALUE self, VALUE pixel_arg)
{
    Image *image;
    Pixel *pixel;
    ExceptionInfo exception;
    char name[MaxTextExtent];

    image = rm_check_destroyed(self);
    Data_Get_Struct(pixel_arg, Pixel, pixel);
    GetExceptionInfo(&exception);

    // QueryColorname returns False if the color represented by the PixelPacket
    // doesn't have a "real" name, just a sequence of hex digits. We don't care
    // about that.

    name[0] = '\0';
    (void) QueryColorname(image, pixel, AllCompliance, name, &exception);
    CHECK_EXCEPTION()

    (void) DestroyExceptionInfo(&exception);

    return rb_str_new2(name);

}


/*
    Method:     Image#total_colors
    Purpose:    alias for Image#number_colors
    Notes:      This used to be a direct reference to the `total_colors' field in Image
                but that field is not reliable.
*/
VALUE
Image_total_colors(VALUE self)
{
    return Image_number_colors(self);
}


/*
    Method:     Image#total_ink_density
    Purpose:    Return value from GetImageTotalInkDensity
    Notes:      Raises an exception if the image is not CMYK
*/
VALUE
Image_total_ink_density(VALUE self)
{
    Image *image;
    double density;

    image = rm_check_destroyed(self);
    density = GetImageTotalInkDensity(image);
    rm_check_image_exception(image, RetainOnError);
    return rb_float_new(density);
}


/*
    Method:     Image#transparent(color-name<, opacity>)
                Image#transparent(pixel<, opacity>)
    Purpose:    Call TransparentPaintImage
    Notes:      Can use Magick::OpaqueOpacity or Magick::TransparentOpacity,
                or any value >= 0 && <= QuantumRange. The default is
                Magick::TransparentOpacity.
                Use Image#fuzz= to define the tolerance level.
*/
VALUE
Image_transparent(int argc, VALUE *argv, VALUE self)
{
    Image *image, *new_image;
    MagickPixelPacket color;
    Quantum opacity = TransparentOpacity;
    MagickBooleanType okay;

    image = rm_check_destroyed(self);

    switch (argc)
    {
        case 2:
            opacity = APP2QUANTUM(argv[1]);
        case 1:
            Color_to_MagickPixelPacket(image, &color, argv[0]);
            break;
        default:
            rb_raise(rb_eArgError, "wrong number of arguments (%d for 1 or 2)", argc);
            break;
    }

    new_image = rm_clone_image(image);

#if defined(HAVE_TRANSPARENTPAINTIMAGE)
    okay = TransparentPaintImage(new_image, &color, opacity, MagickFalse);
#else
    okay = PaintTransparentImage(new_image, &color, opacity);
#endif
    rm_check_image_exception(new_image, DestroyOnError);
    if (!okay)
    {
        // Force exception
        DestroyImage(new_image);
        rm_magick_error("TransparentPaintImage failed with no explanation", NULL);
    }

    return rm_image_new(new_image);
}


/*
    Method:     Image#transparent_chroma(low, high, opacity=TransparentOpacity, invert=false)
    Purpose:    Call TransparentPaintImageChroma (>= 6.4.5-6)
*/
VALUE
Image_transparent_chroma(int argc, VALUE *argv, VALUE self)
{
#if defined(HAVE_TRANSPARENTPAINTIMAGECHROMA)
    Image *image, *new_image;
    Quantum opacity = TransparentOpacity;
    MagickPixelPacket low, high;
    MagickBooleanType invert = MagickFalse;
    MagickBooleanType okay;

    image = rm_check_destroyed(self);

    switch (argc)
    {
        case 4:
            invert = RTEST(argv[3]);
        case 3:
            opacity = APP2QUANTUM(argv[2]);
        case 2:
            Color_to_MagickPixelPacket(image, &high, argv[1]);
            Color_to_MagickPixelPacket(image, &low, argv[0]);
            break;
        default:
            rb_raise(rb_eArgError, "wrong number of arguments (%d for 2, 3 or 4)", argc);
            break;
    }

    new_image = rm_clone_image(image);

    okay = TransparentPaintImageChroma(new_image, &low, &high, opacity, invert);
    rm_check_image_exception(new_image, DestroyOnError);
    if (!okay)
    {
        // Force exception
        DestroyImage(new_image);
        rm_magick_error("TransparentPaintImageChroma failed with no explanation", NULL);
    }

    return rm_image_new(new_image);
#else
    rm_not_implemented();
    return (VALUE)0;
    argc = argc;
    argv = argv;
    self = self;
#endif
}


/*
    Method:     Image#transparent_color
    Purpose:    Return the name of the transparent color as a String.
*/
VALUE
Image_transparent_color(VALUE self)
{
    Image *image = rm_check_destroyed(self);
    return rm_pixelpacket_to_color_name(image, &image->transparent_color);
}


/*
    Method:     Image#transparent_color=
    Purpose:    Set the the transparent color to the specified color spec.
*/
VALUE
Image_transparent_color_eq(VALUE self, VALUE color)
{
    Image *image = rm_check_frozen(self);
    Color_to_PixelPacket(&image->transparent_color, color);
    return self;
}


/*
 *  Method:     Image#transpose
 *              Image#transpose!
 *  Purpose:    Call TransposeImage
 */
VALUE
Image_transpose(VALUE self)
{
    (void) rm_check_destroyed(self);
    return crisscross(False, self, TransposeImage);
}


VALUE
Image_transpose_bang(VALUE self)
{
    (void) rm_check_frozen(self);
    return crisscross(True, self, TransposeImage);
}


/*
 *  Method:     Image#transverse
 *              Image#transverse!
 *  Purpose:    Call TransverseImage
 */
VALUE
Image_transverse(VALUE self)
{
    (void) rm_check_destroyed(self);
    return crisscross(False, self, TransverseImage);
}

VALUE
Image_transverse_bang(VALUE self)
{
    (void) rm_check_frozen(self);
    return crisscross(True, self, TransverseImage);
}


/*
 *  Method:     Image#trim, Image#trim!
 *  Purpose:    convenience front-end to CropImage
 *  Notes:      respects fuzz attribute
 */

static VALUE
trimmer(int bang, int argc, VALUE *argv, VALUE self)
{
    Image *image, *new_image;
    ExceptionInfo exception;
    int reset_page = 0;

    switch (argc)
    {
        case 1:
            reset_page = RTEST(argv[0]);
        case 0:
            break;
        default:
            rb_raise(rb_eArgError, "wrong number of arguments (expecting 0 or 1, got %d)", argc);
            break;
    }

    Data_Get_Struct(self, Image, image);

    GetExceptionInfo(&exception);
    new_image = TrimImage(image, &exception);
    rm_check_exception(&exception, new_image, DestroyOnError);

    (void) DestroyExceptionInfo(&exception);

    rm_ensure_result(new_image);

    if (reset_page)
    {
        ResetImagePage(new_image, "0x0+0+0");
    }

    if (bang)
    {
        UPDATE_DATA_PTR(self, new_image);
        (void) rm_image_destroy(image);
        return self;
    }

    return rm_image_new(new_image);
}


VALUE
Image_trim(int argc, VALUE *argv, VALUE self)
{
    (void) rm_check_destroyed(self);
    return trimmer(False, argc, argv, self);
}


VALUE
Image_trim_bang(int argc, VALUE *argv, VALUE self)
{
    (void) rm_check_frozen(self);
    return trimmer(True, argc, argv, self);
}


/*
    Method:     Image#gravity, gravity=
    Purpose:    Get/set the image gravity attribute
*/
VALUE Image_gravity(VALUE self)
{
    Image *image = rm_check_destroyed(self);
    return GravityType_new(image->gravity);
}


VALUE Image_gravity_eq(VALUE self, VALUE gravity)
{
    Image *image = rm_check_frozen(self);
    VALUE_TO_ENUM(gravity, image->gravity, GravityType);
    return gravity;
}


/*
    Method:     Image#image_type, image_type=
    Purpose:    Call GetImageType/SetImageType to get/set the image type
*/
VALUE Image_image_type(VALUE self)
{
    Image *image;
    ImageType type;
    ExceptionInfo exception;

    image = rm_check_destroyed(self);
    GetExceptionInfo(&exception);
    type = GetImageType(image, &exception);
    CHECK_EXCEPTION()

    (void) DestroyExceptionInfo(&exception);

    return ImageType_new(type);
}


VALUE Image_image_type_eq(VALUE self, VALUE image_type)
{
    Image *image;
    ImageType type;

    image = rm_check_frozen(self);
    VALUE_TO_ENUM(image_type, type, ImageType);
    SetImageType(image, type);
    return image_type;
}


/*
    Method:     Image#undefine(artifact)
    Purpose:    Call RemoveImageArtifact
    Note:       Normally a script should never call this method.
                See Image_define.
*/
VALUE
Image_undefine(VALUE self, VALUE artifact)
{
#if defined(HAVE_REMOVEIMAGEARTIFACT)
    Image *image;
    char *key;
    long key_l;

    image = rm_check_frozen(self);
    key = rm_str2cstr(artifact, &key_l);
    (void) RemoveImageArtifact(image, key);
    return self;
#else
    rm_not_implemented();
    artifact = artifact;
    self = self;
    return(VALUE)0;
#endif
}


/*
    Method:     Image#unique_colors
    Purpose:    Call UniqueImageColors
*/
VALUE
Image_unique_colors(VALUE self)
{
    Image *image, *new_image;
    ExceptionInfo exception;

    image = rm_check_destroyed(self);
    GetExceptionInfo(&exception);

    new_image = UniqueImageColors(image, &exception);
    rm_check_exception(&exception, new_image, DestroyOnError);
    (void) DestroyExceptionInfo(&exception);

    rm_ensure_result(new_image);

    return rm_image_new(new_image);
}


/*
    Method:     Image#units
    Purpose:    Get the resolution type field
*/
VALUE
Image_units(VALUE self)
{
    Image *image = rm_check_destroyed(self);
    return ResolutionType_new(image->units);
}


/*
    Method:     Image#units=
    Purpose:    Set the resolution type field
*/
VALUE
Image_units_eq(
              VALUE self,
              VALUE restype)
{
    ResolutionType units;
    Image *image = rm_check_frozen(self);

    VALUE_TO_ENUM(restype, units, ResolutionType);

    if (image->units != units)
    {
        switch (image->units)
        {
            case PixelsPerInchResolution:
                if (units == PixelsPerCentimeterResolution)
                {
                    image->x_resolution /= 2.54;
                    image->y_resolution /= 2.54;
                }
                break;

            case PixelsPerCentimeterResolution:
                if (units == PixelsPerInchResolution)
                {
                    image->x_resolution *= 2.54;
                    image->y_resolution *= 2.54;
                }
                break;

            default:
                // UndefinedResolution
                image->x_resolution = 0.0;
                image->y_resolution = 0.0;
                break;
        }

        image->units = units;
    }

    return self;
}


/*
    Method:     Image#unsharp_mask(radius=0.0, sigma=1.0, amount=1.0, threshold=0.05)
    Purpose:    sharpens an image. "amount" is the percentage of the difference
                between the original and the blur image that is added back into
                the original. "threshold" is the threshold in pixels needed to
                apply the diffence amount.
*/
static void
unsharp_mask_args(int argc, VALUE *argv, double *radius, double *sigma
                  , double *amount, double *threshold)
{
    switch (argc)
    {
        case 4:
            *threshold = NUM2DBL(argv[3]);
            if (*threshold < 0.0)
            {
                rb_raise(rb_eArgError, "threshold must be >= 0.0");
            }
        case 3:
            *amount = NUM2DBL(argv[2]);
            if (*amount <= 0.0)
            {
                rb_raise(rb_eArgError, "amount must be > 0.0");
            }
        case 2:
            *sigma = NUM2DBL(argv[1]);
            if (*sigma == 0.0)
            {
                rb_raise(rb_eArgError, "sigma must be != 0.0");
            }
        case 1:
            *radius = NUM2DBL(argv[0]);
            if (*radius < 0.0)
            {
                rb_raise(rb_eArgError, "radius must be >= 0.0");
            }
        case 0:
            break;

            // This case can't occur if we're called from Image_unsharp_mask_channel
            // because it has already raised an exception for the the argc > 4 case.
        default:
            rb_raise(rb_eArgError, "wrong number of arguments (%d for 0 to 4)", argc);
    }
}


VALUE
Image_unsharp_mask(int argc, VALUE *argv, VALUE self)
{
    Image *image, *new_image;
    double radius = 0.0, sigma = 1.0, amount = 1.0, threshold = 0.05;
    ExceptionInfo exception;

    image = rm_check_destroyed(self);

    unsharp_mask_args(argc, argv, &radius, &sigma, &amount, &threshold);

    GetExceptionInfo(&exception);
    new_image = UnsharpMaskImage(image, radius, sigma, amount, threshold, &exception);
    rm_check_exception(&exception, new_image, DestroyOnError);

    (void) DestroyExceptionInfo(&exception);

    rm_ensure_result(new_image);

    return rm_image_new(new_image);
}


/*
    Method:     Image#unsharp_mask_channel(radius, sigma, amount,threshold,
                                           channel=AllChannels)
    Purpose:    Call UnsharpMaskImageChannel
*/
VALUE
Image_unsharp_mask_channel(int argc, VALUE *argv, VALUE self)
{
    Image *image, *new_image;
    ChannelType channels;
    double radius = 0.0, sigma = 1.0, amount = 1.0, threshold = 0.05;
    ExceptionInfo exception;

    image = rm_check_destroyed(self);
    channels = extract_channels(&argc, argv);
    if (argc > 4)
    {
        raise_ChannelType_error(argv[argc-1]);
    }

    unsharp_mask_args(argc, argv, &radius, &sigma, &amount, &threshold);

    GetExceptionInfo(&exception);
    new_image = UnsharpMaskImageChannel(image, channels, radius, sigma, amount
                                        , threshold, &exception);
    rm_check_exception(&exception, new_image, DestroyOnError);

    (void) DestroyExceptionInfo(&exception);

    rm_ensure_result(new_image);

    return rm_image_new(new_image);
}


/*
  Method:   Image#vignette(horz_radius, vert_radius, radius, sigma);
  Purpose:  soften the edges of an image
  Notes:    The outer edges of the image are replaced by the background color.
*/
VALUE
Image_vignette(int argc, VALUE *argv, VALUE self)
{
    Image *image, *new_image;
    long horz_radius, vert_radius;
    double radius = 0.0, sigma = 10.0;
    ExceptionInfo exception;

    image = rm_check_destroyed(self);

    horz_radius = (long)(image->columns * 0.10 + 0.5);
    vert_radius = (long)(image->rows * 0.10 + 0.5);

    switch (argc)
    {
        case 4:
            sigma = NUM2DBL(argv[3]);
        case 3:
            radius = NUM2DBL(argv[2]);
        case 2:
            vert_radius = NUM2INT(argv[1]);
        case 1:
            horz_radius = NUM2INT(argv[0]);
        case 0:
            break;
        default:
            rb_raise(rb_eArgError, "wrong number of arguments (%d for 0 to 4)", argc);
            break;
    }

    GetExceptionInfo(&exception);

    new_image = VignetteImage(image, radius, sigma, horz_radius, vert_radius, &exception);
    rm_check_exception(&exception, new_image, DestroyOnError);

    (void) DestroyExceptionInfo(&exception);

    rm_ensure_result(new_image);

    return rm_image_new(new_image);
}


/*
  Method:   Image#virtual_pixel_method
  Purpose:  get the VirtualPixelMethod for the image
*/
VALUE
Image_virtual_pixel_method(VALUE self)
{
    Image *image;
    VirtualPixelMethod vpm;

    image = rm_check_destroyed(self);
    vpm = GetImageVirtualPixelMethod(image);
    rm_check_image_exception(image, RetainOnError);
    return VirtualPixelMethod_new(vpm);
}


/*
  Method:   Image#virtual_pixel_method=
  Purpose:  set the virtual pixel method for the image
*/
VALUE
Image_virtual_pixel_method_eq(VALUE self, VALUE method)
{
    Image *image;
    VirtualPixelMethod vpm;

    image = rm_check_frozen(self);
    VALUE_TO_ENUM(method, vpm, VirtualPixelMethod);
    (void) SetImageVirtualPixelMethod(image, vpm);
    rm_check_image_exception(image, RetainOnError);
    return self;
}


/*
  Method:   Image#watermark(mark, brightness=100.0, saturation=100.0
                          , [gravity,] x_off=0, y_off=0)
  Purpose:  add a watermark to an image
  Notes:    x_off and y_off can be negative, which means measure from the right/bottom
            of the target image.
*/
VALUE
Image_watermark(int argc, VALUE *argv, VALUE self)
{
    Image *image, *overlay, *new_image;
    double src_percent = 100.0, dst_percent = 100.0;
    long x_offset = 0L, y_offset = 0L;
    char geometry[20];
    volatile VALUE ovly;

    image = rm_check_destroyed(self);

    if (argc < 1)
    {
        rb_raise(rb_eArgError, "wrong number of arguments (%d for 2 to 6)", argc);
    }

    ovly = rm_cur_image(argv[0]);
    overlay = rm_check_destroyed(ovly);

    if (argc > 3)
    {
        get_composite_offsets(argc-3, &argv[3], image, overlay, &x_offset, &y_offset);
        // There must be 3 arguments left
        argc = 3;
    }

    switch (argc)
    {
        case 3:
            dst_percent = rm_percentage(argv[2]) * 100.0;
        case 2:
            src_percent = rm_percentage(argv[1]) * 100.0;
        case 1:
            break;
        default:
            rb_raise(rb_eArgError, "wrong number of arguments (%d for 2 to 6)", argc);
            break;
    }

    blend_geometry(geometry, sizeof(geometry), src_percent, dst_percent);
    (void) CloneString(&overlay->geometry, geometry);

    new_image = rm_clone_image(image);
    (void) CompositeImage(new_image, ModulateCompositeOp, overlay, x_offset, y_offset);

    rm_check_image_exception(new_image, DestroyOnError);

    return rm_image_new(new_image);
}


/*
  Method:   Image#wave(amplitude=25.0, wavelength=150.0)
  Purpose:  creates a "ripple" effect in the image by shifting the pixels
            vertically along a sine wave whose amplitude and wavelength is
            specified by the given parameters.
  Returns:  self
*/
VALUE
Image_wave(int argc, VALUE *argv, VALUE self)
{
    Image *image, *new_image;
    double amplitude = 25.0, wavelength = 150.0;
    ExceptionInfo exception;

    image = rm_check_destroyed(self);
    switch (argc)
    {
        case 2:
            wavelength = NUM2DBL(argv[1]);
        case 1:
            amplitude = NUM2DBL(argv[0]);
        case 0:
            break;
        default:
            rb_raise(rb_eArgError, "wrong number of arguments (%d for 0 to 2)", argc);
            break;
    }

    GetExceptionInfo(&exception);
    new_image = WaveImage(image, amplitude, wavelength, &exception);
    rm_check_exception(&exception, new_image, DestroyOnError);

    (void) DestroyExceptionInfo(&exception);

    rm_ensure_result(new_image);

    return rm_image_new(new_image);
}


/*
    Method:     Image#wet_floor(initial, rate)
    Purpose:    Construct a "wet floor" reflection.
    Notes:      `initial' is a number between 0 and 1, inclusive, that represents
                the initial level of transparency. Smaller numbers are less
                transparent than larger numbers. 0 is fully opaque. 1.0 is
                fully transparent. The default is 0.5.
                `rate' is the rate at which the initial level of transparency
                changes to complete transparency. The default is 1.0. Values
                larger than 1.0 cause the change to occur more rapidly. The
                resulting reflection will be shorter. Values smaller than 1.0
                cause the change to occur less rapidly. The resulting
                reflection will be taller. If the rate is exactly 0 then the
                amount of transparency doesn't change at all.
    Notes:      http://en.wikipedia.org/wiki/Wet_floor_effect
*/
VALUE
Image_wet_floor(int argc, VALUE *argv, VALUE self)
{
    Image *image, *reflection, *flip_image;
    const PixelPacket *p;
    PixelPacket *q;
    RectangleInfo geometry;
    long x, y, max_rows;
    double initial = 0.5;
    double rate = 1.0;
    double opacity, step;
    const char *func;
    ExceptionInfo exception;

    image = rm_check_destroyed(self);
    switch (argc)
    {
        case 2:
            rate = NUM2DBL(argv[1]);
        case 1:
            initial = NUM2DBL(argv[0]);
        case 0:
            break;
        default:
            rb_raise(rb_eArgError, "wrong number of arguments (%d for 0 to 2)", argc);
            break;
    }


    if (initial < 0.0 || initial > 1.0)
    {
        rb_raise(rb_eArgError, "Initial transparency must be in the range 0.0-1.0 (%g)", initial);
    }
    if (rate < 0.0)
    {
        rb_raise(rb_eArgError, "Transparency change rate must be >= 0.0 (%g)", rate);
    }

    initial *= TransparentOpacity;

    // The number of rows in which to transition from the initial level of
    // transparency to complete transparency. rate == 0.0 -> no change.
    if (rate > 0.0)
    {
        max_rows = (long)((double)image->rows) / (3.0 * rate);
        max_rows = (long)min((unsigned long)max_rows, image->rows);
        step =  (TransparentOpacity - initial) / max_rows;
    }
    else
    {
        max_rows = (long)image->rows;
        step = 0.0;
    }


    GetExceptionInfo(&exception);
    flip_image = FlipImage(image, &exception);
    CHECK_EXCEPTION();


    geometry.x = 0;
    geometry.y = 0;
    geometry.width = image->columns;
    geometry.height = max_rows;
    reflection = CropImage(flip_image, &geometry, &exception);
    DestroyImage(flip_image);
    CHECK_EXCEPTION();


    (void) SetImageStorageClass(reflection, DirectClass);
    rm_check_image_exception(reflection, DestroyOnError);


    reflection->matte = MagickTrue;
    opacity = initial;

    for (y = 0; y < max_rows; y++)
    {
        if (opacity > TransparentOpacity)
        {
            opacity = TransparentOpacity;
        }


#if defined(HAVE_GETVIRTUALPIXELS)
        p = GetVirtualPixels(reflection, 0, y, image->columns, 1, &exception);
#else
        p = AcquireImagePixels(reflection, 0, y, image->columns, 1, &exception);
#endif
        rm_check_exception(&exception, reflection, DestroyOnError);
        if (!p)
        {
            func = "AcquireImagePixels";
            goto error;
        }

#if defined(HAVE_QUEUEAUTHENTICPIXELS)
        q = QueueAuthenticPixels(reflection, 0, y, image->columns, 1, &exception);
#else
        q = SetImagePixels(reflection, 0, y, image->columns, 1);
#endif
        rm_check_exception(&exception, reflection, DestroyOnError);
        if (!q)
        {
            func = "SetImagePixels";
            goto error;
        }

        for (x = 0; x < (long) image->columns; x++)
        {
            q[x] = p[x];
            // Never make a pixel *less* transparent than it already is.
            q[x].opacity = max(q[x].opacity, (Quantum)opacity);
        }


#if defined(HAVE_SYNCAUTHENTICPIXELS)
        SyncAuthenticPixels(reflection, &exception);
        rm_check_exception(&exception, reflection, DestroyOnError);
#else
        SyncImagePixels(reflection);
        rm_check_image_exception(reflection, DestroyOnError);
#endif

        opacity += step;
    }


    (void) DestroyExceptionInfo(&exception);
    return rm_image_new(reflection);

    error:
    (void) DestroyExceptionInfo(&exception);
    (void) DestroyImage(reflection);
    rb_raise(rb_eRuntimeError, "%s failed on row %lu", func, y);
    return(VALUE)0;
}


/*
 *  Method:     Image#white_threshold(red_channel [, green_channel
 *                                    [, blue_channel [, opacity_channel]]]);
 *  Purpose:    Call WhiteThresholdImage
*/
VALUE
Image_white_threshold(int argc, VALUE *argv, VALUE self)
{
    return threshold_image(argc, argv, self, WhiteThresholdImage);
}


/*
   Copy the filename to the Info and to the Image. Add format
   prefix if necessary. This complicated code is necessary to handle filenames
   like the kind Tempfile.new produces, which have an "extension" in the form
   ".n", which confuses SetMagickInfo. So we don't use SetMagickInfo any longer.
*/
void add_format_prefix(Info *info, VALUE file)
{
    char *filename;
    long filename_l;
    const MagickInfo *magick_info, *magick_info2;
    ExceptionInfo exception;
    char magic[MaxTextExtent];
    size_t magic_l;
    size_t prefix_l;
    char *p;

    // Convert arg to string. If an exception occurs raise an error condition.
    file = rb_rescue(rb_String, file, file_arg_rescue, file);

    filename = rm_str2cstr(file, &filename_l);

    if (*info->magick == '\0')
    {
        memset(info->filename, 0, sizeof(info->filename));
        memcpy(info->filename, filename, (size_t)min(filename_l, MaxTextExtent-1));
        return;
    }

    // If the filename starts with a prefix, and it's a valid image format
    // prefix, then check for a conflict. If it's not a valid format prefix,
    // ignore it.
    p = memchr(filename, ':', (size_t)filename_l);
    if (p)
    {
        memset(magic, '\0', sizeof(magic));
        magic_l = p - filename;
        memcpy(magic, filename, magic_l);

        GetExceptionInfo(&exception);
        magick_info = GetMagickInfo(magic, &exception);
        CHECK_EXCEPTION();
        DestroyExceptionInfo(&exception);

        if (magick_info && magick_info->module)
        {
            // We have to compare the module names because some formats have
            // more than one name. JPG and JPEG, for example.
            GetExceptionInfo(&exception);
            magick_info2 = GetMagickInfo(info->magick, &exception);
            CHECK_EXCEPTION();
            DestroyExceptionInfo(&exception);

            if (magick_info2->module && strcmp(magick_info->module, magick_info2->module) != 0)
            {
                rb_raise(rb_eRuntimeError
                         , "filename prefix `%s' conflicts with output format `%s'"
                         , magick_info->name, info->magick);
            }

            // The filename prefix already matches the specified format.
            // Just copy the filename as-is.
            memset(info->filename, 0, sizeof(info->filename));
            filename_l = min((size_t)filename_l, sizeof(info->filename));
            memcpy(info->filename, filename, (size_t)filename_l);
            return;
        }
    }

    // The filename doesn't start with a format prefix. Add the format from
    // the image info as the filename prefix.

    memset(info->filename, 0, sizeof(info->filename));
    prefix_l = min(sizeof(info->filename)-1, strlen(info->magick));
    memcpy(info->filename, info->magick, prefix_l);
    info->filename[prefix_l++] = ':';

    filename_l = min(sizeof(info->filename) - prefix_l - 1, (size_t)filename_l);
    memcpy(info->filename+prefix_l, filename, (size_t)filename_l);
    info->filename[prefix_l+filename_l] = '\0';

    return;
}


/*
  Method:   Image#write(filename)
  Purpose:  Write the image to the file.
  Returns:  self
*/
VALUE
Image_write(VALUE self, VALUE file)
{
    Image *image;
    Info *info;
    volatile VALUE info_obj;

    image = rm_check_destroyed(self);

    info_obj = rm_info_new();
    Data_Get_Struct(info_obj, Info, info);

    if (TYPE(file) == T_FILE)
    {
        OpenFile *fptr;

        // Ensure file is open - raise error if not
        GetOpenFile(file, fptr);
        rb_io_check_writable(fptr);
        SetImageInfoFile(info, GetWriteFile(fptr));
        memset(image->filename, 0, sizeof(image->filename));
    }
    else
    {
        add_format_prefix(info, file);
        strcpy(image->filename, info->filename);
        SetImageInfoFile(info, NULL);
    }

    rm_sync_image_options(image, info);

    info->adjoin = MagickFalse;
    (void) WriteImage(info, image);
    rm_check_image_exception(image, RetainOnError);

    return self;
}


DEF_ATTR_ACCESSOR(Image, x_resolution, dbl)

DEF_ATTR_ACCESSOR(Image, y_resolution, dbl)


/*
    Static:     cropper
    Purpose:    determine if the argument list is
                    x, y, width, height
                or
                    gravity, width, height
                or
                    gravity, x, y, width, height
                If the 2nd or 3rd, compute new x, y values.

                The argument list can have a trailing true, false, or nil argument.
                If present and true, after cropping reset the page fields in the image.

                Call xform_image to do the cropping.
*/
static VALUE
cropper(int bang, int argc, VALUE *argv, VALUE self)
{
    volatile VALUE x, y, width, height;
    unsigned long nx = 0, ny = 0;
    unsigned long columns, rows;
    int reset_page = 0;
    GravityType gravity;
    MagickEnum *m_enum;
    Image *image;
    VALUE cropped;

    // Check for a "reset page" trailing argument.
    if (argc >= 1)
    {
        switch (TYPE(argv[argc-1]))
        {
            case T_TRUE:
                reset_page = 1;
                // fall thru
            case T_FALSE:
            case T_NIL:
                argc -= 1;
            default:
                break;
        }
    }

    switch (argc)
    {
        case 5:
            Data_Get_Struct(self, Image, image);

            VALUE_TO_ENUM(argv[0], gravity, GravityType);

            x      = argv[1];
            y      = argv[2];
            width  = argv[3];
            height = argv[4];

            nx      = NUM2ULONG(x);
            ny      = NUM2ULONG(y);
            columns = NUM2ULONG(width);
            rows    = NUM2ULONG(height);

            switch (gravity)
            {
                case NorthEastGravity:
                case EastGravity:
                case SouthEastGravity:
                    nx = image->columns - columns - nx;
                    break;
                case NorthGravity:
                case SouthGravity:
                case CenterGravity:
                case StaticGravity:
                    nx += image->columns/2 - columns/2;
                    break;
                default:
                    break;
            }
            switch (gravity)
            {
                case SouthWestGravity:
                case SouthGravity:
                case SouthEastGravity:
                    ny = image->rows - rows - ny;
                    break;
                case EastGravity:
                case WestGravity:
                case CenterGravity:
                case StaticGravity:
                    ny += image->rows/2 - rows/2;
                    break;
                case NorthEastGravity:
                case NorthGravity:
                    // Don't let these run into the default case
                    break;
                default:
                    Data_Get_Struct(argv[0], MagickEnum, m_enum);
                    rb_warning("gravity type `%s' has no effect", rb_id2name(m_enum->id));
                    break;
            }

            x = ULONG2NUM(nx);
            y = ULONG2NUM(ny);
            break;
        case 4:
            x      = argv[0];
            y      = argv[1];
            width  = argv[2];
            height = argv[3];
            break;
        case 3:

            // Convert the width & height arguments to unsigned longs.
            // Compute the x & y offsets from the gravity and then
            // convert them to VALUEs.
            VALUE_TO_ENUM(argv[0], gravity, GravityType);
            width   = argv[1];
            height  = argv[2];
            columns = NUM2ULONG(width);
            rows    = NUM2ULONG(height);

            Data_Get_Struct(self, Image, image);

            switch (gravity)
            {
                case ForgetGravity:
                case NorthWestGravity:
                    nx = 0;
                    ny = 0;
                    break;
                case NorthGravity:
                    nx = (image->columns - columns) / 2;
                    ny = 0;
                    break;
                case NorthEastGravity:
                    nx = image->columns - columns;
                    ny = 0;
                    break;
                case WestGravity:
                    nx = 0;
                    ny = (image->rows - rows) / 2;
                    break;
                case EastGravity:
                    nx = image->columns - columns;
                    ny = (image->rows - rows) / 2;
                    break;
                case SouthWestGravity:
                    nx = 0;
                    ny = image->rows - rows;
                    break;
                case SouthGravity:
                    nx = (image->columns - columns) / 2;
                    ny = image->rows - rows;
                    break;
                case SouthEastGravity:
                    nx = image->columns - columns;
                    ny = image->rows - rows;
                    break;
                case StaticGravity:
                case CenterGravity:
                    nx = (image->columns - columns) / 2;
                    ny = (image->rows - rows) / 2;
                    break;
            }

            x = ULONG2NUM(nx);
            y = ULONG2NUM(ny);
            break;
        default:
            if (reset_page)
            {
                rb_raise(rb_eArgError, "wrong number of arguments (%d for 4, 5, or 6)", argc);
            }
            else
            {
                rb_raise(rb_eArgError, "wrong number of arguments (%d for 3, 4, or 5)", argc);
            }
            break;
    }

    cropped = xform_image(bang, self, x, y, width, height, CropImage);
    if (reset_page)
    {
        Data_Get_Struct(cropped, Image, image);
        ResetImagePage(image, "0x0+0+0");
    }
    return cropped;
}


/*
    Static:     xform_image
    Purpose:    call one of the image transformation functions
    Returns:    a new image, or transformed self
*/
static VALUE
xform_image(int bang, VALUE self, VALUE x, VALUE y, VALUE width, VALUE height, xformer_t xformer)
{
    Image *image, *new_image;
    RectangleInfo rect;
    ExceptionInfo exception;

    Data_Get_Struct(self, Image, image);
    rect.x      = NUM2LONG(x);
    rect.y      = NUM2LONG(y);
    rect.width  = NUM2ULONG(width);
    rect.height = NUM2ULONG(height);

    GetExceptionInfo(&exception);

    new_image = (xformer)(image, &rect, &exception);

    // An exception can occur in either the old or the new images
    rm_check_image_exception(image, RetainOnError);
    rm_check_exception(&exception, new_image, DestroyOnError);

    (void) DestroyExceptionInfo(&exception);

    rm_ensure_result(new_image);

    if (bang)
    {
        UPDATE_DATA_PTR(self, new_image);
        (void) rm_image_destroy(image);
        return self;
    }

    return rm_image_new(new_image);

}


/*
    Extern:     extract_channels
    Purpose:    Remove all the ChannelType arguments from the
                end of the argument list.
    Returns:    A ChannelType value suitable for passing into
                an xMagick function. Returns DefaultChannels if
                no channel arguments were found. Returns the
                number of remaining arguments.
*/
ChannelType extract_channels(int *argc, VALUE *argv)
{
    volatile VALUE arg;
    ChannelType channels, ch_arg;

    channels = 0;
    while (*argc > 0)
    {
        arg = argv[(*argc)-1];

        // Stop when you find a non-ChannelType argument
        if (CLASS_OF(arg) != Class_ChannelType)
        {
            break;
        }
        VALUE_TO_ENUM(arg, ch_arg, ChannelType);
        channels |= ch_arg;
        *argc -= 1;
    }

    if (channels == 0)
    {
        channels = DefaultChannels;
    }

    return channels;
}


/*
    Extern:     raise_ChannelType_error
    Purpose:    raise TypeError when an non-ChannelType object
                is unexpectedly encountered
*/
void
raise_ChannelType_error(VALUE arg)
{
    rb_raise(rb_eTypeError, "argument must be a ChannelType value (%s given)"
             , rb_class2name(CLASS_OF(arg)));
}



/*
    Static:     call_trace_proc
    Purpose:    If Magick.trace_proc is not nil, build an argument
                list and call the proc.
*/
static void call_trace_proc(Image *image, const char *which)
{
    volatile VALUE trace;
    VALUE trace_args[4];

    if (rb_ivar_defined(Module_Magick, rm_ID_trace_proc) == Qtrue)
    {
        trace = rb_ivar_get(Module_Magick, rm_ID_trace_proc);
        if (!NIL_P(trace))
        {
            // Maybe the stack won't get extended until we need the space.
            char buffer[MaxTextExtent];
            int n;

            trace_args[0] = ID2SYM(rb_intern(which));

            build_inspect_string(image, buffer, sizeof(buffer));
            trace_args[1] = rb_str_new2(buffer);

            n = sprintf(buffer, "%p", (void *)image);
            buffer[n] = '\0';
            trace_args[2] = rb_str_new2(buffer+2);      // don't use leading 0x
            trace_args[3] = ID2SYM(THIS_FUNC());
            (void) rb_funcall2(trace, rm_ID_call, 4, (VALUE *)trace_args);
        }
    }

}


/*
    External:   rm_trace_creation
    Purpose:    should be obvious
*/
void rm_trace_creation(Image *image)
{
    call_trace_proc(image, "c");
}



/*
    External:   rm_image_destroy
    Purpose:    Called from GC when all references to the image have gone out
                of scope.
    Notes:      A NULL Image pointer indicates that the image has already been
                destroyed by Image#destroy!
*/
void rm_image_destroy(void *img)
{
    Image *image = (Image *)img;

    if (img != NULL)
    {
        call_trace_proc(image, "d");
        (void) DestroyImage(image);
    }
}

#to_blobObject

#to_colorObject

#transparentObject

#transparent_chromaObject

#transposeObject

#transpose!Object

#transverseObject

#transverse!Object

#trimObject

#trim!Object

#undefineObject

#unique_colorsObject

#unsharp_maskObject

#unsharp_mask_channelObject

#view(x, y, width, height) ⇒ Object

Construct a view. If a block is present, yield and pass the view object, otherwise return the view object.


1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
# File 'lib/RMagick.rb', line 1020

def view(x, y, width, height)
    view = View.new(self, x, y, width, height)

    if block_given?
        begin
            yield(view)
        ensure
            view.sync
        end
        return nil
    else
        return view
    end
end

#vignetteObject

#watermarkObject

#waveObject

#wet_floorObject

#white_thresholdObject

#writeObject