ShowMouseClick.cc

#include "opencv2/highgui/highgui.hpp"
#include <iostream>

using namespace std;
using namespace cv;

void CallBackFunc(int event, int x, int y, int flags, void* userdata)
{
     if  ( event == EVENT_LBUTTONDOWN )
     {
          cout << "Left button clicked " << x << " " << y << endl;
     }
     else if  ( event == EVENT_RBUTTONDOWN )
     {
          cout << "Right button clicked " << x << " " << y << endl;
     }
     else if  ( event == EVENT_MBUTTONDOWN )
     {
          cout << "Middle button is clicked " << x << " " << y << endl;
     }
     else if (flags == CV_EVENT_FLAG_LBUTTON)
     {
          cout << "Mouse move over the window " << x << " " << y << endl;
     }
}

int main(int argc, char** argv)
{
     // Read image from file 
     Mat img = imread(string(argv[1]));
      //if fail to read the image
     if ( img.empty() ) 
     { 
          cout << "Error loading the image" << endl;
          return -1; 
     }
      //Create a window
     namedWindow("My Window", 1);
      //set the callback function for any mouse event
     setMouseCallback("My Window", CallBackFunc, NULL);
      //show the image
     imshow("My Window", img);
      // Wait until user press some key
     waitKey(0);
      return 0;
}