docs: public static <T extends ImageGray<T>>
  	DenseOpticalFlow<T> hornSchunckPyramid( @Nullable ConfigHornSchunckPyramid config , Class<T> imageType )
  	{
  		if( config == null )
  			config = new ConfigHornSchunckPyramid();
  
  		InterpolatePixelS<GrayF32> interpolate =
  				FactoryInterpolation.createPixelS(0,255,config.interpolation, BorderType.EXTENDED, GrayF32.class);
  
  		HornSchunckPyramid<T> alg = new HornSchunckPyramid<>(config, interpolate);
  
  		return new HornSchunckPyramid_to_DenseOpticalFlow<>(alg, imageType);
  	}