code: private void selectCandidateTracks() {
  		// mark tracks in right frame that are active
  		List<PointTrack> activeRight = trackerRight.getActiveTracks(null);
  		for( PointTrack t : activeRight ) {
  			RightTrackInfo info = t.getCookie();
  			info.lastActiveList = tick;
  		}
  
  		int mutualActive = 0;
  		List<PointTrack> activeLeft = trackerLeft.getActiveTracks(null);
  		candidates.clear();
  		for( PointTrack left : activeLeft ) {
  			LeftTrackInfo info = left.getCookie();
  
  //			if( info == null || info.right == null ) {
  //				System.out.println("Oh Crap");
  //			}
  
  			// for each active left track, see if its right track has been marked as active
  			RightTrackInfo infoRight = info.right.getCookie();
  			if( infoRight.lastActiveList != tick ) {
  				continue;
  			}
  
  			// check epipolar constraint and see if it is still valid
  			if( stereoCheck.checkPixel(left, info.right) ) {
  				info.lastConsistent = tick;
  				candidates.add(left);
  			}
  			mutualActive++;
  		}
  
  //		System.out.println("Active Tracks: Left "+trackerLeft.getActiveTracks(null).size()+" right "+
  //				trackerRight.getActiveTracks(null).size());
  //		System.out.println("All Tracks:    Left "+trackerLeft.getAllTracks(null).size()+" right "+
  //				trackerRight.getAllTracks(null).size());
  //		System.out.println("Candidates = "+candidates.size()+" mutual active = "+mutualActive);
  	}
docs: Searches for tracks which are active and meet the epipolar constraints