/**

 * @function EqualizeHist_Demo.cpp

 * @brief Demo code for equalizeHist function

 * @author OpenCV team

 */

#include "opencv2/highgui/highgui.hpp"

#include "opencv2/imgproc/imgproc.hpp"

#include <iostream>

#include <stdio.h>

using namespace cv;

using namespace std;

/**

 * @function main

 */

int main( int, char** argv )

{

  Mat src;

  const char* equalized_window = "Equalized Image";

  /// Load image

  src = imread( argv[1], 0 ); // load grayscale

  if( !src.data )

    { cout<<"Usage: ./Histogram_Demo <path_to_image>"<<endl;

      return -1;

    }

  CV_Assert(src.rows >= 250 && src.cols >= 250);

  cv::Mat roi(src, cv::Rect(200,200,50,50));

  cv::Mat dst;

  /// Apply Histogram Equalization

  equalizeHist( roi, dst );

  /// Display results

  namedWindow( equalized_window, CV_WINDOW_AUTOSIZE );

  imshow( equalized_window, dst );

  /// Wait until user exits the program

  waitKey(0);

  cv::imwrite("dst.png", dst);

  return 0;

}