noise.h

#pragma once

#ifndef NOISE_H
#define NOISE_H
#include<iostream>
#include "opencv2/opencv.hpp"


using namespace std;
using namespace cv;

double generateGaussianNoise(double mu, double sigma)
{
	//定义小值
	const double epsilon = numeric_limits<double>::min();
	static double z0, z1;
	static bool flag = false;
	flag = !flag;
	//flag为假构造高斯随机变量X
	if (!flag)
		return z1 * sigma + mu;
	double u1, u2;
	//构造随机变量
	do
	{
		u1 = rand() * (1.0 / RAND_MAX);
		u2 = rand() * (1.0 / RAND_MAX);
	} while (u1 <= epsilon);
	//flag为真构造高斯随机变量
	z0 = sqrt(-2.0 * log(u1)) * cos(2 * CV_PI * u2);
	z1 = sqrt(-2.0 * log(u1)) * sin(2 * CV_PI * u2);
	return z0 * sigma + mu;
}

//为图像添加高斯噪声
Mat addGaussianNoise(Mat& srcImag)
{
	Mat dstImage = srcImag.clone();
	for (int i = 0; i < dstImage.rows; i++)
	{
		for (int j = 0; j < dstImage.cols; j++)
		{
			//添加高斯噪声
			dstImage.at<Vec3b>(i, j)[0] = saturate_cast<uchar>(dstImage.at<Vec3b>(i, j)[0] + generateGaussianNoise(2, 0.8) * 32);
			dstImage.at<Vec3b>(i, j)[1] = saturate_cast<uchar>(dstImage.at<Vec3b>(i, j)[1] + generateGaussianNoise(2, 0.8) * 32);
			dstImage.at<Vec3b>(i, j)[2] = saturate_cast<uchar>(dstImage.at<Vec3b>(i, j)[2] + generateGaussianNoise(2, 0.8) * 32);
		}
	}
	return dstImage;
}


//添加椒盐噪声
Mat addSaltNoise(const Mat srcImage, int n)
{
	Mat dstImage = srcImage.clone();
	for (int k = 0; k < n; k++)
	{
		//随机取值行列
		int i = rand() % dstImage.rows;
		int j = rand() % dstImage.cols;
		//图像通道判定
		if (dstImage.channels() == 1)
		{
			dstImage.at<uchar>(i, j) = 255;		//盐噪声
		}
		else
		{
			dstImage.at<Vec3b>(i, j)[0] = 255;
			dstImage.at<Vec3b>(i, j)[1] = 255;
			dstImage.at<Vec3b>(i, j)[2] = 255;
		}
	}
	for (int k = 0; k < n; k++)
	{
		//随机取值行列
		int i = rand() % dstImage.rows;
		int j = rand() % dstImage.cols;
		//图像通道判定
		if (dstImage.channels() == 1)
		{
			dstImage.at<uchar>(i, j) = 0;		//椒噪声
		}
		else
		{
			dstImage.at<Vec3b>(i, j)[0] = 0;
			dstImage.at<Vec3b>(i, j)[1] = 0;
			dstImage.at<Vec3b>(i, j)[2] = 0;
		}
	}
	return dstImage;
}

#endif