This is the code which i tried, only the coordinate values are printed but not the pixel values.
#include <iostream>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/imgproc/imgproc.hpp>
void onMouse( int event, int x, int y, int, void* );
using namespace cv;
Mat img = cv::imread("b.jpg", 0); // force grayscale
Mat thresh=Mat::zeros(img.size(),CV_8UC1);
int main(int argc, char **argv)
{
if(!img.data) {
std::cout << "File not found" << std::endl;
return -1;
}
threshold(img,binary,50,255,THRESH_TOZERO);
namedWindow("thresh");
setMouseCallback( "thresh", onMouse, 0 );
imshow("thresh",thresh);
}
void onMouse( int event, int x, int y, int, void* )
{
if( event != CV_EVENT_LBUTTONDOWN )
return;
Point pt = Point(x,y);
std::cout<<"x="<<pt.x<<"\t y="<<pt.y<<"\t value="<<thresh.at<uchar>(x,y)<<"\n";
}
I got the output as :-
The coordinate values are printed but the pixel values are not printed properly. What is the mistake i committed??
cout prints uchar's as characters, like the ones you see.
just wrap them with a cast to int for the printing:
cout << int( thresh.at<uchar>(y,x) )
also note, that it's at<uchar>(y,x), not x,y