opencv - How to capture image from video when right button of mouse is clicked in open cv c++ -

i working open cv , facing problem in capturing image video. basic need when video running in open cv ,as click right button of mouse program should capture image video image should saved @ location. after on saved image have perform further image processing. please 1 me.

this simple. need mouse callback, write image, , running clip, therefore code question.

#include <iostream> #include <string> #include <sstream> #include <opencv2/core/core.hpp> #include <opencv2/highgui/highgui.hpp>    cv::mat currentframe;   static void onmouse( int event, int x, int y, int, void* )  {     static int count(0);     if ( event == cv::event_rbuttondown ) {        std::stringstream ss;       ss << count;       std::string countstr = ss.str();       std::string imagename = "image_" + countstr;       std::string fullpath = "/home/xxxx/" + imagename + ".jpg";       cv::imwrite( fullpath, currentframe );       std::cout << " image has been saved " << std::endl;       ++count;    }  }  int main() {      std::string clipfullpath = "/home/xxxx/drop.avi";     cv::videocapture clip(clipfullpath);            if ( !clip.isopened() ){         std::cout  << "error: not open  video: " << std::endl;         return -1;     }       cv::namedwindow("display", cv_window_autosize);     cv::setmousecallback("display", onmouse, 0 );      for(;;){         clip >> currentframe;            if ( currentframe.empty() )                break;                  cv::imshow("display", currentframe);         cv::waitkey(30);      }     return 0; } 

you need -std=c++11 std::to_string(). if want save image through gui window, think need library such qt supports functionality.

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edited: op needs capturing frames webcam rather video.

this code question in comment.

#include <iostream> #include <cstdlib> #include <string> #include <sstream> #include "opencv2/core/core.hpp" #include "opencv2/highgui/highgui.hpp"   cv::mat frame;   static void onmouse( int event, int x, int y, int, void* )  {     static int count(0);     if ( event == cv::event_rbuttondown ) {        std::stringstream ss;       ss << count;       std::string countstr = ss.str();       std::string imagename = "image_" + countstr;       std::string fullpath = imagename + ".jpg"; // save current directory       cv::imwrite( fullpath, frame );       std::cout << " image has been saved " << std::endl;       ++count;    } }   int main() {     // access default webcam      cv::videocapture cap(0);       // double check webcam before start reading.      if ( !cap.isopened() ){          std::cerr  << "cannot open webcam " << std::endl;         exit (exit_failure);     }      cv::namedwindow("webcam",cv_window_autosize);     cv::setmousecallback("webcam", onmouse, 0 );      while ( true ){         // acquire frame         cap >> frame;         // safety checking         if ( !frame.data ){           std::cerr << "cannot acquire frame webcam " << std::endl;             break;        }         cv::imshow("webcam", frame);          if ( cv::waitkey(30) == 27){         std::cout << "esc key pressed" << std::endl;         break;         }     }      return 0; }  

the images saved in directory of executable file. in terminal command (i.e. i'm using mac , opencv 2.4.11 )

g++ main.cpp -o main -i/opt/local/include -l/opt/local/lib -lopencv_highgui.2.4.11 -lopencv_core.2.4.11