对文件夹下所有图像做灰度转换，并做garma校正，产生不同的灰度亮度范围，方案用(13-14)

#pragma once
#include<stdio.h>
#include<opencv2/highgui/highgui.hpp>
#include<opencv2/core/core.hpp>
#include <cstdio>
#include <string>
#include <iostream>
#include <stdint.h>#include "opencv2/core.hpp"
#include <opencv2/opencv.hpp>
#include <math.h>
#include <io.h>
using namespace std;
using namespace cv;
#ifdef _DEBUG
#pragma comment(lib,"opencv_world340d.lib")
#else
#pragma comment(lib,"opencv_world340.lib")
#endif/*
1.读取整个文件夹中的所有图像
2.做灰度化处理，设置不同的灰度化方案，效果是，亮度不同
3.写入到不同的文件夹，文件夹命名不同
*/void getFiles(string path, vector<string>& files)
{intptr_t   hFile = 0;//intptr_t和uintptr_t是什么类型:typedef long int/ typedef unsigned long intstruct _finddata_t fileinfo;string p;if ((hFile = _findfirst(p.assign(path).append("\\*").c_str(), &fileinfo)) != -1)//assign方法可以理解为先将原字符串清空，然后赋予新的值作替换。{do{if ((fileinfo.attrib &  _A_SUBDIR))//是否为文件夹{if (strcmp(fileinfo.name, ".") != 0 && strcmp(fileinfo.name, "..") != 0)getFiles(p.assign(path).append("\\").append(fileinfo.name), files);//子文件夹下递归访问}else//非文件夹{files.push_back(p.assign(path).append("\\").append(fileinfo.name));}} while (_findnext(hFile, &fileinfo) == 0);_findclose(hFile);}
}void MyGammaCorrection(Mat& src, Mat& dst, float fGamma)
{CV_Assert(src.data);// accept only char type matricesCV_Assert(src.depth() != sizeof(uchar));// build look up tableunsigned char lut[256];for (int i = 0; i < 256; i++){lut[i] = saturate_cast<uchar>(pow((float)(i / 255.0), fGamma) * 255.0f);}dst = src.clone();const int channels = dst.channels();switch (channels){case 1:{MatIterator_<uchar> it, end;for (it = dst.begin<uchar>(), end = dst.end<uchar>(); it != end; it++)//*it = pow((float)(((*it))/255.0), fGamma) * 255.0;*it = lut[(*it)];break;}case 3:{MatIterator_<Vec3b> it, end;for (it = dst.begin<Vec3b>(), end = dst.end<Vec3b>(); it != end; it++){(*it)[0] = lut[((*it)[0])];(*it)[1] = lut[((*it)[1])];(*it)[2] = lut[((*it)[2])];}break;}}
}void RGBtoGray(string gallery_path, string form)
{vector<string> gallery_folders;getFiles(gallery_path, gallery_folders);int  nameNUM = 0;vector<string> image_list;for (int g = 0; g < gallery_folders.size(); g++) {if (gallery_folders[g].substr(gallery_folders[g].find_last_of(".") + 1) == form){//获取文件夹下指定格式(如jpg格式)的文件的路径(全路径)Mat src, OutMat;src = cv::imread(gallery_folders[g]);cv::cvtColor(src, src, CV_BGR2GRAY);//彩色转灰度MyGammaCorrection(src, src,1.0);vector<Mat> vHls;vHls.push_back(src);vHls.push_back(src);vHls.push_back(src);merge(vHls, OutMat);//输出要求依然是三通道，所以，构建一个三通道都是灰度图像的新图像imwrite(gallery_folders[g], OutMat);//写入到当前项目目录下             }}cout << "over";
}

调用方法：

void main()
{
//获得E:\\vincen\\OSG\\原始资料\\数据资料\\启明模型\\Models下面所有“jpg”格式文件，并做灰度转换和garma校正RGBtoGray("E:\\vincen\\OSG\\原始资料\\数据资料\\启明模型\\Models", "jpg");
}