Get to know opencv4.x for the first time --- add Gaussian noise to the image

// Add Gaussian noise to the image 
#include <stdio.h>
#include <iostream>
#include <string>
#include <opencv2\opencv.hpp>
using namespace std;
using namespace cv;
int main()
{
    
	// The distribution probability density of noise in the image satisfies Gaussian distribution  
	Mat img = imread("person3.jpeg");// Read the three channel image 
	namedWindow(" Original picture ", WINDOW_NORMAL);
	imshow(" Original picture ", img);
	// Generate a size with the original image , Gaussian noise image of the same type 
	Mat noise = Mat::zeros(img.rows, img.cols, img.type());
	RNG rng;
	rng.fill(noise, RNG::NORMAL, 10, 20);// establish RNG Class is to be able to call fill The function is used to generate random numbers with Gaussian distribution 
	// Adding the noise image and the original image can produce Gaussian noise effect 
	img = img + noise;
	namedWindow(" Gauss diagram ", WINDOW_NORMAL);
	imshow(" Gauss diagram ", img);
	waitKey(0);
	return 0;
}