Opencv 3 installation, Difference between Frames and Averaging Frames

Find difference between frames

The following openCV code will help you to check changes between two frames and display result in a window.

CvCapture* capture;
	Mat pFrame;
	Mat cFrame;

	capture = cvCaptureFromAVI("video.avi");
	cvNamedWindow( "video", CV_WINDOW_AUTOSIZE );
	if( capture )
	{
		while( 1 )
		{
		    pFrame = cFrame.clone();
		    cFrame = cvQueryFrame( capture );
		 if( pFrame.empty() ){
		    pFrame=cFrame.clone();
		  }


		  if(cFrame.empty())
			  break;

		   Mat diff = cFrame-pFrame;
	       imshow( "video", diff );
	       waitKey(1);
	     }
	   }
	    cvDestroyWindow("video");

Averaging Specified Number of Frame in OpenCV

The following OpenCV code helps you to find average frame model for background subtraction purpose. This code is tested on EWAP pedestrian data set. An average frame is extracted and upload below.

//Add source of video and name
VideoCapture cap("myVid.avi");

if(!cap.isOpened()){
   cout<<"Capture Not Opened"<<endl; } 
//Number of frames to take average of 
  int count = 0; 
  const int width = cap.get(CV_CAP_PROP_FRAME_WIDTH); 
  const int height = cap.get(CV_CAP_PROP_FRAME_HEIGHT); 
  Mat frame, frame32f; 
  Mat resultframe = Mat::zeros(height,width,CV_32FC3); 
  while(1) { 
    cap>>frame;
	       
 if(frame.empty()){
    cout<<"Capture Finished"<
Average frame computed from EWAP dataset

Single frame extracted from EWAP dataset






																									
Tags:averaging frames, difference between frames, openCV installation