常见的图像梯度算子:
一阶导数算子:
#include <opencv2/opencv.hpp>
#include <iostream>
using namespace cv;
using namespace std;
int main(int argc, char** argv)
{
Mat src = imread("f:/images/lena.jpg");
if (src.empty())
{
printf("Could not find the image!\n");
return -1;
}
namedWindow("input", WINDOW_AUTOSIZE);
imshow("input", src);
Mat grad_x, grad_y;
Mat result;
// robot
Mat robot_x = (Mat_<int>(2, 2) << 1, 0, 0, -1);
Mat robot_y = (Mat_<int>(2, 2) << 0, 1, -1, 0);
filter2D(src, grad_x, CV_32F, robot_x, Point(-1, -1), 0, BORDER_DEFAULT);
filter2D(src, grad_y, CV_32F, robot_y, Point(-1, -1), 0, BORDER_DEFAULT);
convertScaleAbs(grad_x, grad_x);
convertScaleAbs(grad_y, grad_y);
imshow("robot_x", grad_x);
imshow("robot_y", grad_y);
add(grad_x, grad_y, result);
imshow("robot_result", result);
// sobel
Sobel(src, grad_x, CV_32F, 1, 0, 3);
Sobel(src, grad_y, CV_32F, 0, 1, 3);
convertScaleAbs(grad_x, grad_x);
convertScaleAbs(grad_y, grad_y);
imshow("sobel_x", grad_x);
imshow("sobel_y", grad_y);
//add(grad_x, grad_y, result);
addWeighted(grad_x, 0.5, grad_y, 0.5, 0, result);
imshow("sobel_result", result);
// scharr
Scharr(src, grad_x, CV_32F, 1, 0, 3);
Scharr(src, grad_y, CV_32F, 0, 1, 3);
convertScaleAbs(grad_x, grad_x);
convertScaleAbs(grad_y, grad_y);
imshow("scharr_x", grad_x);
imshow("scharr_y", grad_y);
//add(grad_x, grad_y, result);
addWeighted(grad_x, 0.5, grad_y, 0.5, 0, result);
imshow("scharr_result", result);
waitKey(0);
destroyAllWindows();
return 0;
}