Class: OpenCV::CvScalar

Inherits:
Object
  • Object
show all
Defined in:
ext/opencv/cvscalar.cpp,
ext/opencv/cvscalar.cpp

Overview

Element-value of one pixel. OpenCV supports the image of 4-channels in the maximum. Therefore, CvScalar has 4-values.

C structure is here, very simple.

typdef struct CvScalar {
  double val[4];
} CvScalar;

If obtain CvScalar-object from the method of CvMat(or IplImage), the channel outside the range is obtained as all 0.

image = IplImage::load("opencv.jpg")  #=> 3-channel 8bit-depth BGR image
pixel = image[10, 20]                 #=> Get pixel value of (10, 20) of image. pixel is CvScalar-object.
blue, green, red = pixel[0], pixel[1], pixel[2]
# pixel[3] always 0.

CvColor is alias of CvScalar.

Constant Summary collapse

Black = 
cCvScalar::new_object(cvScalar(0x0,0x0,0x0))
Silver = 
cCvScalar::new_object(cvScalar(0x0c,0x0c,0x0c))
Gray = 
cCvScalar::new_object(cvScalar(0x80,0x80,0x80))
White = 
cCvScalar::new_object(cvScalar(0xff,0xff,0xff))
Maroon = 
cCvScalar::new_object(cvScalar(0x0,0x0,0x80))
Red = 
cCvScalar::new_object(cvScalar(0x0,0x0,0xff))
Purple = 
cCvScalar::new_object(cvScalar(0x80,0x0,0x80))
Fuchsia = 
cCvScalar::new_object(cvScalar(0xff,0x0,0xff))
Green = 
cCvScalar::new_object(cvScalar(0x0,0x80,0x0))
Lime = 
cCvScalar::new_object(cvScalar(0x0,0xff,0x0))
Olive = 
cCvScalar::new_object(cvScalar(0x0,0x80,0x80))
Yellow = 
cCvScalar::new_object(cvScalar(0x0,0xff,0xff))
cCvScalar::new_object(cvScalar(0x80,0x0,0x0))
Blue = 
cCvScalar::new_object(cvScalar(0xff,0x0,0x0))
Teal = 
cCvScalar::new_object(cvScalar(0x80,0x80,0x0))
Aqua = 
cCvScalar::new_object(cvScalar(0xff,0xff,0x0))

Instance Method Summary collapse

Constructor Details

#new([d1][,d2][,d3][,d4]) ⇒ Object

Create new Scalar. Argument should be Fixnum (or nil as 0).



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# File 'ext/opencv/cvscalar.cpp', line 58

VALUE
rb_initialize(int argc, VALUE *argv, VALUE self)
{
  VALUE val[4];
  rb_scan_args(argc, argv, "04", &val[0], &val[1], &val[2], &val[3]);
  CvScalar* self_ptr = CVSCALAR(self);
  for (int i = 0; i < 4; ++i) {
    self_ptr->val[i] = NIL_P(val[i]) ? 0 : NUM2DBL(val[i]);
  }
  return self;
}

Instance Method Details

#[](index) ⇒ Object

Return value of index dimension.



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# File 'ext/opencv/cvscalar.cpp', line 76

VALUE
rb_aref(VALUE self, VALUE index)
{
  int idx = NUM2INT(index);
  if (idx < 0 || idx >= 4) {
    rb_raise(rb_eIndexError, "scalar index should be 0...4");
  }
  return rb_float_new(CVSCALAR(self)->val[idx]);
}

#[]=(index, value) ⇒ Object

Set value of index dimension to value



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# File 'ext/opencv/cvscalar.cpp', line 92

VALUE
rb_aset(VALUE self, VALUE index, VALUE value)
{
  int idx = NUM2INT(index);
  if (idx < 0 || idx >= 4) {
    rb_raise(rb_eIndexError, "scalar index should be 0...4");
  }
  CVSCALAR(self)->val[idx] = NUM2DBL(value);
  return self;
}

#sub(val[,mask]) ⇒ Object Also known as: -

Return new CvScalar if val is CvScalar or compatible object.

self[I] - val[I]

Or return new CvMat if val is CvMat or subclass.



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# File 'ext/opencv/cvscalar.cpp', line 111

VALUE
rb_sub(int argc, VALUE *argv, VALUE self)
{
  VALUE val, mask;
  rb_scan_args(argc, argv, "11", &val, &mask);
  if (rb_obj_is_kind_of(val, cCvMat::rb_class())) {
    CvArr *val_ptr = CVARR(val);
    VALUE dest = Qnil;
    try {
      dest = cCvMat::new_object(cvGetSize(val_ptr), cvGetElemType(val_ptr));
      cvSubRS(val_ptr, *CVSCALAR(self), CVARR(dest), MASK(mask));
    }
    catch (cv::Exception& e) {
      raise_cverror(e);
    }
    return dest;
  }
  else {
    CvScalar *src = CVSCALAR(self);
    CvScalar scl = VALUE_TO_CVSCALAR(val);
    return new_object(cvScalar(src->val[0] - scl.val[0],
                               src->val[1] - scl.val[1],
                               src->val[2] - scl.val[2],
                               src->val[3] - scl.val[3]));
  }
}

#to_ary ⇒ Array Also known as: to_a

Return values by Array.

Returns:

  • (Array) 


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# File 'ext/opencv/cvscalar.cpp', line 164

VALUE
rb_to_ary(VALUE self)
{
  return rb_ary_new3(4,
		     rb_aref(self, INT2FIX(0)),
		     rb_aref(self, INT2FIX(1)),
		     rb_aref(self, INT2FIX(2)),
		     rb_aref(self, INT2FIX(3)));
}

#to_s ⇒ "<OpeCV::CvScalar:#selff[0]}

Return values by String.

Returns:

  • ("<OpeCV::CvScalar:#selff[0]}) 


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# File 'ext/opencv/cvscalar.cpp', line 144

VALUE
rb_to_s(VALUE self)
{
  const int i = 6;
  VALUE str[i];
  str[0] = rb_str_new2("<%s:%g,%g,%g,%g>");
  str[1] = rb_str_new2(rb_class2name(CLASS_OF(self)));
  str[2] = rb_aref(self, INT2FIX(0));
  str[3] = rb_aref(self, INT2FIX(1));
  str[4] = rb_aref(self, INT2FIX(2));
  str[5] = rb_aref(self, INT2FIX(3));
  return rb_f_sprintf(i, str);
}