c++ opencv color map rgb conversion hsv channel separation

// An highlighted block
Mat img_hsv;
    cvtColor(img, img_hsv, COLOR_BGR2HSV);
    vector<Mat> hsvSplit;
    split(img_hsv, hsvSplit);
    Mat h1 = hsvSplit[0];
    Mat h2 = hsvSplit[1];
    Mat h3 = hsvSplit[2];

img

img_hsv

h1

h2

h3