#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 */
	Mat src, src_gray;
	Mat dst, detected_edges;

	int edgeThresh = 1;
	int lowThreshold;
	int const max_lowThreshold = 100;
	int ratio = 3;
	int kernel_size = 3;
	char* window_name = "Edge Map";

	/**
	* @function CannyThreshold
	* @brief Trackbar callback - Canny thresholds input with a ratio 1:3
	*/
	void CannyThreshold(int, void*)
	{
		/// Reduce noise with a kernel 3x3
		blur(src, detected_edges, Size(3, 3));

		/// Canny detector
		Canny(detected_edges, detected_edges, lowThreshold, lowThreshold*ratio, kernel_size);

		/// Using Canny's output as a mask, we display our result
		dst = Scalar::all(0);

		src.copyTo(dst, detected_edges);
		imshow(window_name, dst);
	}


	/** @function main */
	int main(int argc, char** argv)
	{
		/// Load an image
		src = imread("d:/image/cameraman2.tif", IMREAD_GRAYSCALE);

			/// Create a matrix of the same type and size as src (for dst)
		dst.create(src.size(), src.type());


		/// Create a window
		namedWindow(window_name, CV_WINDOW_AUTOSIZE);

		/// Create a Trackbar for user to enter threshold
		createTrackbar("Min Threshold:", window_name, &lowThreshold, max_lowThreshold, CannyThreshold);

		/// Show the image
		CannyThreshold(0, 0);

		/// Wait until user exit program by pressing a key
		waitKey(0);

		return 0;
	
}
/** @function readme */