code: public void process( T image1 , T image2 , ImageFlow output) {
  
  		InputSanityCheck.checkSameShape(image1,image2);
  
  		derivX.reshape(image1.width,image1.height);
  		derivY.reshape(image1.width,image1.height);
  		derivT.reshape(image1.width,image1.height);
  
  		averageFlow.reshape(output.width,output.height);
  
  		if( resetOutput )
  			output.fillZero();
  
  		computeDerivX(image1,image2,derivX);
  		computeDerivY(image1,image2,derivY);
  		computeDerivT(image1,image2,derivT);
  
  		findFlow(derivX,derivY,derivT,output);
  	}
docs: Computes dense optical flow from the first image's gradient and the difference between
  the second and the first image.
  
  @param image1 First image
  @param image2 Second image
  @param output Found dense optical flow