在x y的梯度上再求一次导数后相加便是散度。注意不要使用convertScaleAbs
int main(int argc, char*argv[])
{
cv::Mat IMG = cv::imread("./img.jpg", 1);
cv::Mat k = getStructuringElement(cv::MORPH_RECT, cv::Size(3, 3), cv::Point(-1, -1));
cv::Mat graySrc, grad_x, grad_y;
cv::Mat abs_grad_x, abs_grad_y;
cv::cvtColor(IMG, graySrc, cv::COLOR_BGR2GRAY);
//cv::GaussianBlur(graySrc, graySrc, cv::Size(3,3), 0, 0, 4);
// 计算x方向的散度
cv::Mat Sobel_x = (Mat_<char>(3, 3) << -1, 0, 1, -2, 0, 2, -1, 0, 1);
filter2D(graySrc, grad_x, CV_64FC1, Sobel_x, cv::Point(-1, -1), 0, 0);
filter2D(grad_x, grad_x, CV_64FC1, Sobel_x, cv::Point(-1, -1), 0, 0);
// Sobel(grad_x, grad_x, CV_32FC1, 1, 0, 3, 1, 0, cv::BORDER_DEFAULT);
//convertScaleAbs(grad_x, abs_grad_x);
// 计算y方向的散度
cv::Mat Sobel_y = (Mat_<char>(3, 3) << 1, 2, 1, 0, 0, 0, -1, -2, -1);
filter2D(graySrc, grad_y, CV_64FC1, Sobel_y, cv::Point(-1, -1), 0, 0);
filter2D(grad_y, grad_y, CV_64FC1, Sobel_y, cv::Point(-1, -1), 0, 0);
// Sobel(grad_y, grad_y, CV_32FC1, 0, 1, 3, 1, 0, cv::BORDER_DEFAULT);
//convertScaleAbs(grad_y, abs_grad_y);
// 合并散度
cv::Mat divImage;
addWeighted(grad_x, 0.5, grad_y, 0.5, 0, divImage);
//morphologyEx(divImage, divImage, cv::MORPH_OPEN, k);
morphologyEx(divImage, divImage, cv::MORPH_CLOSE, k);
cv::imwrite("dstGradientImage.jpg", divImage);
}