opencv--读取Mat像素点值

    Mat src = imread("1.jpg");
    int rows = src.rows;
    int cols = src.cols; 
    for (int i = 0; i < rows; i++)
    {
        uchar* d = src.ptr<uchar>(i);  //获取第i行的首地址
        for (int j = 0; j < cols; j++)
        {
            int b = d[j * 3];
            int g = d[j * 3 + 1];
            int r = d[j * 3 + 2];
        }
    }