OpenCV cvtColor

OpenCV cvtColor function convert image from one colour space to another, such as from BGR to Gray, BGR to RGB, BGR to HSV, also by default OpenCV imread load image in BGR mode.

C++ cvtColor function

    void cvtColor(InputArray src, OutputArray dst, int conv_code, int dstCn=0 )

Where,
     src ---> Input Image
     dst ---> Output Image
     conv_code --->conversion code(COLOR_BGR2GRAY,COLOR_BGR2HSV,COLOR_BGR2RGB etc..)
     dstCn ---> Number of channel in desensitisation image.

How to use cvtColor C++

Load Image from disk,

    Mat src = imread("flower.jpg",IMREAD_COLOR);
    if(! src.data )  {
       std::cout <<  "Could not open or find the image" << std::endl ;
        return -1;
    }
    imshow("src",src);

BGR To Gary

    Mat dst;
    cvtColor(src,dst,COLOR_BGR2GRAY);

BGR To HSV

    cvtColor(src,dst,COLOR_BGR2HSV);

BGR To RGB

    cvtColor(src,dst,COLOR_BGR2RGB);