code: public static <I extends ImageGray<I>, O extends ImageGray<O>>
  	void filter(ImagePyramid<I> input, FilterImageInterface<I, O> filter, O[] output )
  	{
  		for( int i = 0; i < input.getNumLayers(); i++ ) {
  			I imageIn = input.getLayer(i);
  			filter.process(imageIn,output[i]);
  		}
  	}
docs: <p>
  Runs an image filter through each layer in the pyramid.
  </p>
  
  <p>
  It is assumed that the output has the same scales as the input.  If not
  initialized then it will be initialized.  If already initialized it is
  assumed to be setup for the same input image size.
  </p>
  
  @param input Input pyramid.
  @param filter Filter being applied to the pyramid.
  @param output Output pyramid where filter results are saved.