[opencv]RGB与HSV颜色空间转换源码

Mat RGB2HSV(Mat src) {
    int row = src.rows;
    int col = src.cols;
    Mat dst(row, col, CV_32FC3);
    for (int i = 0; i < row; i++) {
        for (int j = 0; j < col; j++) {
            float b = src.at<Vec3b>(i, j)[0] / 255.0;
            float g = src.at<Vec3b>(i, j)[1] / 255.0;
            float r = src.at<Vec3b>(i, j)[2] / 255.0;
            float minn = min(r, min(g, b));
            float maxx = max(r, max(g, b));
            dst.at<Vec3f>(i, j)[2] = maxx; //V
            float delta = maxx - minn;
            float h, s;
            if (maxx != 0) {
                s = delta / maxx;
            }
            else {
                s = 0;
            }
            if (r == maxx) {
                h = (g - b) / delta;
            }
            else if (g == maxx) {
                h = 2 + (b - r) / delta;
            }
            else {
                h = 4 + (r - g) / delta;
            }
            h *= 60;
            if (h < 0)
                h += 360;
            dst.at<Vec3f>(i, j)[0] = h;
            dst.at<Vec3f>(i, j)[1] = s;
        }
    }
    return dst;
}

Mat HSV2RGB(Mat src) {
    int row = src.rows;
    int col = src.cols;
    Mat dst(row, col, CV_8UC3);
    float r, g, b, h, s, v;
    for (int i = 0; i < row; i++) {
        for (int j = 0; j < col; j++) {
            h = src.at<Vec3f>(i, j)[0];
            s = src.at<Vec3f>(i, j)[1];
            v = src.at<Vec3f>(i, j)[2];
            if (s == 0) {
                r = g = b = v;
            }
            else {
                h /= 60;
                int offset = floor(h);
                float f = h - offset;
                float p = v * (1 - s);
                float q = v * (1 - s * f);
                float t = v * (1 - s * (1 - f));
                switch (offset)
                {
                case 0: r = v; g = t; b = p; break;
                case 1: r = q; g = v; b = p; break;
                case 2: r = p; g = v; b = t; break;
                case 3: r = p; g = q; b = v; break;
                case 4: r = t; g = p; b = v; break;
                case 5: r = v; g = p; b = q; break;
                default:
                    break;
                }
            }
            dst.at<Vec3b>(i, j)[0] = int(b * 255);
            dst.at<Vec3b>(i, j)[1] = int(g * 255);
            dst.at<Vec3b>(i, j)[2] = int(r * 255);
        }
    }
    return dst;
}