code: protected void warpImageTaylor(GrayF32 before, GrayF32 flowX , GrayF32 flowY , GrayF32 after) {
  		interp.setBorder(FactoryImageBorder.single(before.getImageType().getImageClass(), BorderType.EXTENDED));
  		interp.setImage(before);
  
  		for( int y = 0; y < before.height; y++ ) {
  			int pixelIndex = y*before.width;
  			for (int x = 0; x < before.width; x++, pixelIndex++ ) {
  				float u = flowX.data[pixelIndex];
  				float v = flowY.data[pixelIndex];
  
  				float wx = x + u;
  				float wy = y + v;
  
  				after.data[pixelIndex] = interp.get(wx, wy);
  			}
  		}
  	}
docs: Takes the flow from the previous lower resolution layer and uses it to initialize the flow
  in the current layer.  Adjusts for change in image scale.