#include <opencv4/opencv2/opencv.hpp>
#include <iostream>
int main(int argc, char** argv){
cv::Mat src = cv::imread("/home/long2double/Desktop/OpenCV_Study/source/lena.png");
if(src.empty()){
std::cout << "could not load image ...." << std::endl;
return -1;
}
cv::namedWindow("test opencv setup");
cv::imshow("test opencv setup", src);
cv::cvtColor(src, src, cv::COLOR_BGR2GRAY);
cv::Mat dst;
cv::equalizeHist(src, dst);
cv::imshow("dst", dst);
cv::waitKey();
}