Mat magX = Mat(src.rows, src.cols, CV_32F);

Mat magY = Mat(src.rows, src.cols, CV_32F);

Sobel(image, magX, CV_32F, 1, 0, 3);

Sobel(image, magY, CV_32F, 0, 1, 3);

// 計算斜率

Mat slopes = Mat(image.rows, image.cols, CV_32F);

divide(magY, magX, slopes);

// 計算每個點的梯度

Mat sum = Mat(image.rows, image.cols, CV_64F);

Mat prodX = Mat(image.rows, image.cols, CV_64F);

Mat prodY = Mat(image.rows, image.cols, CV_64F);

multiply(magX, magX, prodX);

multiply(magY, magY, prodY);

sum = prodX + prodY;

sqrt(sum, sum);