code: public boolean process(ImagePyramid<I> image , Rectangle2D_F64 targetRectangle ) {
  
  		boolean success = true;
  		updateCurrent(image);
  
  		// create feature tracks
  		spawnGrid(targetRectangle);
  
  		// track features while computing forward/backward error and NCC error
  		if( !trackFeature() )
  			success = false;
  
  		// makes the current image into a previous image
  		setCurrentToPrevious();
  
  		return success;
  	}
docs: Creates several tracks inside the target rectangle and compuets their motion
  
  @param image Most recent video image.
  @param targetRectangle Location of target in previous frame. Not modified.
  @return true if tracking was successful or false if not