#include <stdio.h>
#include <iostream> 
#include "opencv2/core/core.hpp"
#include "opencv2/highgui/highgui.hpp"
#include <opencv2/opencv.hpp>
#include "opencv2/imgcodecs.hpp"

using namespace cv;
/** @function main */

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

using namespace cv;
using namespace std;

/// Global variables
Mat src, src_gray;
int thresh = 200;
int max_thresh = 255;

char* source_window = "Source image";
char* corners_window = "Corners detected";

/// Function header
void cornerHarris_demo(int, void*);

/** @function main */
int main(int argc, char** argv)
{
	/// Load source image and convert it to gray
	src = imread("d:/image/cameraman2.tif", IMREAD_GRAYSCALE);

//	src = imread("d:/image/checkerboard.png", IMREAD_GRAYSCALE);
	src_gray = src;

	/// Create a window and a trackbar
	namedWindow(source_window, CV_WINDOW_AUTOSIZE);
	createTrackbar("Threshold: ", source_window, &thresh, max_thresh, cornerHarris_demo);
	imshow(source_window, src);

	cornerHarris_demo(0, 0);

	waitKey(0);
	return(0);
}

/** @function cornerHarris_demo */
void cornerHarris_demo(int, void*)
{

	Mat dst, dst_norm, dst_norm_scaled;
	dst = Mat::zeros(src.size(), CV_32FC1);

	/// Detector parameters
	int blockSize = 2;
	int apertureSize = 3;
	double k = 0.04;

	/// Detecting corners
	cornerHarris(src_gray, dst, blockSize, apertureSize, k, BORDER_DEFAULT);

	/// Normalizing
	normalize(dst, dst_norm, 0, 255, NORM_MINMAX, CV_32FC1, Mat());
	convertScaleAbs(dst_norm, dst_norm_scaled);

	/// Drawing a circle around corners
	for (int j = 0; j < dst_norm.rows; j++)
	{
		for (int i = 0; i < dst_norm.cols; i++)
		{
			if ((int)dst_norm.at<float>(j, i) > thresh)
			{
				circle(dst_norm_scaled, Point(i, j), 5, Scalar(0), 2, 8, 0);
			}
		}
	}
	/// Showing the result
	namedWindow(corners_window, CV_WINDOW_AUTOSIZE);
	imshow(corners_window, dst_norm_scaled);
}
/** @function readme */