docs: protected void interpolateFlowScale(int widthNew, int heightNew) {
  		// warping isn't done until later so use those images as temporary storage
  		GrayF32 enlargedU = warpDeriv2X;
  		GrayF32 enlargedV = warpDeriv2Y;
  
  		// use the previous low resolution flow estimate to initialize the new image
  		interpolateFlowScale(flowU, enlargedU);
  		interpolateFlowScale(flowV, enlargedV);
  
  		flowU.reshape(widthNew, heightNew);
  		flowV.reshape(widthNew, heightNew);
  
  		// save the initial flow values
  		flowU.setTo(enlargedU);
  		flowV.setTo(enlargedV);
  	}