First knowledge of opencv4.x --- image convolution

// Image convolution principle 
#include <stdio.h>
#include <iostream>
#include <string>
#include <opencv2\opencv.hpp>
using namespace std;
using namespace cv;
int main()
{
    
	Mat src = (cv::Mat_<float>(5, 5) <<
		1, 2, 3, 4, 5,
		6, 7, 8, 9, 10,
		11, 12, 13, 14, 15,
		16, 17, 18, 19, 20,
		21, 22, 23, 24, 25);// Enumeration assignment method , You have to put parentheses , Otherwise VS2017 Will report a mistake 
	Mat dst;
	Mat kernel = (cv::Mat_<float>(3, 3) <<
		1, 2, 1,
		0, 2, 0,
		1, 2, 1);
	kernel = kernel / 10;// Divide 10 Normalization , Prevent the pixel value from crossing the boundary after convolution 
	filter2D(src, dst, CV_32F, kernel);
	waitKey(0);
	return 0;
}

adopt Image Watch Plug in view Mat Variable data ：