Method: Magick::Image#opaque_channel

Defined in:

ext/RMagick/rmimage.cpp

#opaque_channel(target, fill, invert = false, fuzz = self.fuzz, channel = Magick::AllChannels) ⇒ Magick::Image #opaque_channel(target, fill, invert, fuzz, *channels) ⇒ Magick::Image

Changes all pixels having the target color to the fill color. If invert is true, changes all the pixels that are not the target color to the fill color.

Overloads:

• #opaque_channel(target, fill, invert = false, fuzz = self.fuzz, channel = Magick::AllChannels) ⇒ Magick::Image

  Parameters:

  • target (Magick::Pixel, String) —

    the color name

  • fill (Magick::Pixel, String) —

    the color for filling

  • invert (Boolean) (defaults to: false) —

    If true, the target pixels are all the pixels that are not the target color. The default is the value of the target image’s fuzz attribute

  • fuzz (Numeric) (defaults to: self.fuzz) —

    Colors within this distance are considered equal to the target color.

  • channel (Magick::ChannelType) (defaults to: Magick::AllChannels) —

    a ChannelType arguments.

• #opaque_channel(target, fill, invert, fuzz, *channels) ⇒ Magick::Image

  Parameters:

  • target (Magick::Pixel, String) —

    the color name

  • fill (Magick::Pixel, String) —

    the color for filling

  • invert (Boolean) —

    If true, the target pixels are all the pixels that are not the target color. The default is the value of the target image’s fuzz attribute

  • fuzz (Numeric) —

    Colors within this distance are considered equal to the target color.

  • *channels (Magick::ChannelType) —

    one or more ChannelType arguments.

Returns:

• (Magick::Image) —

  a new image

# File 'ext/RMagick/rmimage.cpp', line 10239

VALUE
Image_opaque_channel(int argc, VALUE *argv, VALUE self)
{
    Image *image, *new_image;
    MagickPixel target_pp, fill_pp;
    ChannelType channels;
    double keep, fuzz;
    MagickBooleanType okay, invert = MagickFalse;
#if defined(IMAGEMAGICK_7)
    ExceptionInfo *exception;
#endif

    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 = (MagickBooleanType)RTEST(argv[2]);
        case 2:
            // Allow color name or Pixel
            Color_to_MagickPixel(image, &fill_pp, argv[1]);
            Color_to_MagickPixel(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;

#if defined(IMAGEMAGICK_7)
    exception = AcquireExceptionInfo();
    BEGIN_CHANNEL_MASK(new_image, channels);
    GVL_STRUCT_TYPE(OpaquePaintImage) args = { new_image, &target_pp, &fill_pp, invert, exception };
    void *ret = CALL_FUNC_WITHOUT_GVL(GVL_FUNC(OpaquePaintImage), &args);
    okay = static_cast<MagickBooleanType>(reinterpret_cast<intptr_t &>(ret));
    END_CHANNEL_MASK(new_image);
    new_image->fuzz = keep;
    rm_check_exception(exception, new_image, DestroyOnError);
    DestroyExceptionInfo(exception);
#else
    GVL_STRUCT_TYPE(OpaquePaintImageChannel) args = { new_image, channels, &target_pp, &fill_pp, invert };
    void *ret = CALL_FUNC_WITHOUT_GVL(GVL_FUNC(OpaquePaintImageChannel), &args);
    okay = static_cast<MagickBooleanType>(reinterpret_cast<intptr_t &>(ret));

    new_image->fuzz = keep;
    rm_check_image_exception(new_image, DestroyOnError);
#endif

    if (!okay)
    {
        // Force exception
        DestroyImage(new_image);
        rm_ensure_result(NULL);
    }

    return rm_image_new(new_image);
}