RGB to Other Color Space Conversion

cvtcolor() converts an image from one color space to another.

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Syntax :
C++:void cvtColor(InputArray src, OutputArray dst, int code, int dstCn=0 )

Parameter:
src   :– input image: 8-bit unsigned, 16-bit unsigned ( CV_16UC... ), or single-precision floating-point.
dst    :– output image of the same size and depth as src.
code  :– color space conversion code (see the description below).
dstCn :– number of channels in the destination image; if the parameter is 0, the number of the channels is derived automatically from src and code.

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As it has already been mentioned that the functions converts an image form one color space to another, there are various types of conversion possible.

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Transformation	Syntax
RGB to YCrCb	CV_RGB2YCrCb
BGR to YCrCb	CV_BGR2YCrCb
YCrCb to RGB	CV_YCrCb2RGB
YCrCb to BGR	CV_YCrCb2BGR

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Transformation	Syntax
RGB to HSV	CV_RGB2HSV
BGR to HSV	CV_BGR2HSV
HSV to RGB	CV_HSV2RGB
HSV to BGR	CV_HSV2BGR

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Transformation	Syntax
RGB to CIE L*a*b*	CV_RGB2Lab
BGR to CIE L*a*b*	CV_BGR2Lab
CIE L*a*b* to RGB	CV_Lab2RGB
CIE L*a*b* to BGR	CV_Lab2BGR

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Transformation	Syntax
RGB to CIE L*u*v*	CV_RGB2Luv
BGR to CIE L*u*v*	CV_BGR2Luv
CIE L*u*v* to RGB	CV_Luv2RGB
CIE L*u*v* to BGR	CV_Luv2BGR

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Transformation	Syntax
RGB to CIE XYZ	CV_RGB2XYZ
BGR to CIE XYZ	CV_BGR2XYZ
CIE XYZ to RGB	CV_XYZ2RGB
CIE XYZ to BGR	CV_XYZ2BGR

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//OpenCV C++ Code for ColorSpace Conversion
#include "opencv2/core/core.hpp"
#include "opencv2/highgui/highgui.hpp"
#include "opencv2/imgproc/imgproc.hpp"
#include "iostream"
 
using namespace cv;
 
int main( )
{
// char* imageName = argv[1];
 
 Mat image;
 image = imread( "C:\\Users\\arjun\\Desktop\\color-image.png", 1 );
 
 Mat RGB2GRAY_image;
 cvtColor( image, RGB2GRAY_image, CV_RGB2GRAY );
 
 Mat BGR2GRAY_image;
 cvtColor( image, BGR2GRAY_image, CV_BGR2GRAY );
 
 Mat RGB2YCrCb_image;
 cvtColor( image, RGB2YCrCb_image, CV_RGB2YCrCb );
 
 Mat BGR2YCrCb_image;
 cvtColor( image, BGR2YCrCb_image, CV_BGR2YCrCb );
 
 Mat RGB2HSV_image;
 cvtColor( image, RGB2HSV_image, CV_RGB2HSV );
 
 Mat BGR2HSV_image;
 cvtColor( image, BGR2HSV_image, CV_BGR2HSV );
 
 Mat RGB2Lab_image;
 cvtColor( image, RGB2Lab_image, CV_RGB2Lab );
 
 Mat BGR2Lab_image;
 cvtColor( image, BGR2Lab_image, CV_BGR2Lab );
 
 Mat RGB2Luv_image;
 cvtColor( image, RGB2Luv_image, CV_RGB2Luv );
 
  Mat BGR2Luv_image;
 cvtColor( image, BGR2Luv_image, CV_BGR2Luv );
 
 Mat RGB2XYZ_image;
 cvtColor( image, RGB2XYZ_image, CV_RGB2XYZ );
 
 Mat BGR2XYZ_image;
 cvtColor( image, BGR2XYZ_image, CV_BGR2XYZ );
 
 namedWindow( "original image", CV_WINDOW_AUTOSIZE );
imshow( "original image", image );
 
namedWindow( "RGB2GRAY image", CV_WINDOW_AUTOSIZE );
imshow( "RGB2GRAY image",RGB2GRAY_image );
imwrite( "C:\\Users\\arjun\\Desktop\\RGB2GRAY.jpg", RGB2GRAY_image );
 
namedWindow( "BGR2GRAY image", CV_WINDOW_AUTOSIZE );
imshow( "BGR2GRAY image", BGR2GRAY_image );
imwrite( "C:\\Users\\arjun\\Desktop\\BGR2GRAY.jpg", BGR2GRAY_image );
 
namedWindow( "RGB2YCrCb image", CV_WINDOW_AUTOSIZE );
imshow( "RGB2YCrCb image", RGB2YCrCb_image );
imwrite( "C:\\Users\\arjun\\Desktop\\RGB2YCrCb.jpg", RGB2YCrCb_image );
 
 
namedWindow( "BGR2YCrCb image", CV_WINDOW_AUTOSIZE );
imshow( "BGR2YCrCb image", BGR2YCrCb_image );
imwrite( "C:\\Users\\arjun\\Desktop\\BGR2YCrCb.jpg", BGR2YCrCb_image );
 
namedWindow( "RGB2HSV image", CV_WINDOW_AUTOSIZE );
imshow( "RGB2HSV image", RGB2HSV_image );
imwrite( "C:\\Users\\arjun\\Desktop\\RGB2HSV.jpg", RGB2HSV_image );
 
namedWindow( "BGR2HSV image", CV_WINDOW_AUTOSIZE );
imshow( "BGR2HSV image", BGR2HSV_image );
imwrite( "C:\\Users\\arjun\\Desktop\\BGR2HSV.jpg", BGR2HSV_image );
 
namedWindow( "RGB2Lab image", CV_WINDOW_AUTOSIZE );
imshow( "RGB2Lab image", RGB2Lab_image );
imwrite( "C:\\Users\\arjun\\Desktop\\RGB2Lab.jpg", RGB2Lab_image );
 
namedWindow( "BGR2Lab image", CV_WINDOW_AUTOSIZE );
imshow( "BGR2Lab image", BGR2Lab_image );
imwrite( "C:\\Users\\arjun\\Desktop\\BGR2Lab.jpg", BGR2Lab_image );
 
namedWindow( "RGB2Luv image", CV_WINDOW_AUTOSIZE );
imshow( "RGB2Luv image", RGB2Luv_image );
imwrite( "C:\\Users\\arjun\\Desktop\\RGB2Luv.jpg", RGB2Luv_image );
 
namedWindow( "BGR2Luv image", CV_WINDOW_AUTOSIZE );
imshow( "BGR2Luv image", BGR2Luv_image );
imwrite( "C:\\Users\\arjun\\Desktop\\BGR2Luv.jpg", BGR2Luv_image );
 
namedWindow( "RGB2XYZ image", CV_WINDOW_AUTOSIZE );
imshow( "RGB2XYZ image", RGB2XYZ_image );
imwrite( "C:\\Users\\arjun\\Desktop\\RGB2XYZ.jpg", RGB2XYZ_image );
 
namedWindow( "BGR2XYZ image", CV_WINDOW_AUTOSIZE );
imshow( "BGR2XYZ image", BGR2XYZ_image );
imwrite( "C:\\Users\\arjun\\Desktop\\BGR2XYZ.jpg", BGR2XYZ_image );
 
 waitKey(0);
 
 return 0;
}

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Original Image:

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RGB to Grey Image:

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BGR to Grey Image:

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RGB to YCrCb Image:

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BGR to YCrCb Image:

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RGB to HSV Image:

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BGR to HSV Image:

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RGB to Lab Image:

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BGR to Lab Image:

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RGB to Luv Image:

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BGR to Luv Image:

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RGB to XYZ Image:

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BGR to XYZ Image:

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