C++ opencv Histogram Equalization

#include "opencv2/highgui/highgui.hpp"
#include "opencv2/imgproc/imgproc.hpp"
#include <iostream>
#include <stdio.h>

using namespace cv;
using namespace std;


int main(int argc, char** argv)
{
Mat src, dst;

VideoCapture cap(0);
while (1)
{
cap >> src;
dst = src.clone();

/// Convert to grayscale
cvtColor(src, src, CV_BGR2GRAY);

/// Apply Histogram Equalization
equalizeHist(src, dst);

/// Display results
namedWindow("Original image", CV_WINDOW_AUTOSIZE);
namedWindow("equalized_window", CV_WINDOW_AUTOSIZE);

imshow("Original image", src);
imshow("equalized_window", dst);

if (waitKey(30) == 27)
break;
}
return 0;
}