. Canny Edge Detector

#include “opencv2/imgproc.hpp”
#include “opencv2/highgui.hpp”
#include

using namespace cv;

Mat src, src_gray;
Mat dst, detected_edges;
int lowThreshold = 0;
const int max_lowThreshold = 100;
const int ratio = 3;
const int kernel_size = 3;
const char* window_name = “Edge Map”;
static void CannyThreshold(int, void*)
{
blur( src_gray, detected_edges, Size(3,3) );
Canny( detected_edges, detected_edges, lowThreshold, lowThreshold*ratio, kernel_size );
dst = Scalar::all(0);
src.copyTo( dst, detected_edges);
imshow( window_name, dst );
}

int main( int argc, char** argv )
{

src = imread( samples::findFile( "../test.jpg" ), IMREAD_COLOR ); // Load an image
if( src.empty() )
{
std::cout << "Could not open or find the image!\n" << std::endl;
return -1;
}
dst.create( src.size(), src.type() );
cvtColor( src, src_gray, COLOR_BGR2GRAY );
namedWindow( window_name, WINDOW_AUTOSIZE );
createTrackbar( "Min Threshold:", window_name, &lowThreshold, max_lowThreshold, CannyThreshold );
CannyThreshold(0, 0);
waitKey(0);
return 0;

}