Opencv learning log 29 -- gamma correction

Preface

This article focuses on opencv Image processing gamma Application of correction .

One 、gamma correction

// The first question is  gamma correction 
#include <opencv2/opencv.hpp>
#include <iostream>
#include<cmath>
using namespace cv;
using namespace std;

int main()
{
    
	cv::Mat dst;
	cv::Mat dstbin;
	cv::Mat dsttemp;
	cv::Mat finalpicture;
	cv::Mat src = imread("C://Users//john//Desktop//1.jpg");
	cv::Mat srcgray = imread("C://Users//john//Desktop//1.jpg", 0);
	int i, j;
	//cout << sizeof(srcgray) << endl; 538 478
	int row = srcgray.rows;
	int col = srcgray.cols;
	cout << row << endl;
	cout << col << endl;
	int size = row*col;
// double sum = 0;
// cout << 1 / 0.5 << endl;

	float lut[256];//  Definition table 
	float r =0.4;
	for (i = 0; i <= 255; i++)
	{
    
	
		lut[i] =float( i )/float(255);

	}
	float secondlut[256];
	for (i = 0; i <= 255; i++)
	{
    

	
		secondlut[i] = pow(lut[i], r);
	}
	for (int j = 0; j < row; j++)  // Read total gray value 
	{
    
		for (int i = 0; i < col; i++)
		{
    
			uchar average = srcgray.at<uchar>(j, i);
			srcgray.at<uchar>(j, i) = secondlut[average]*255;
		}
	}
	//(x/sum)~r*255
	cout << sum << endl;

	cv::imshow("srcgray", srcgray);
	cv::imshow("final", src);
	waitKey(0);
}

summary

1. The code can run directly , If you don't understand, you can leave a message .
2. Missing material pictures , Follow up, thank you .