docs: public static <T extends ImageGray<T>>
  	T bitmapToGray( Bitmap input , T output , Class<T> imageType , byte[] storage) {
  		if( imageType == GrayF32.class )
  			return (T)bitmapToGray(input,(GrayF32)output,storage);
  		else if( imageType == GrayU8.class )
  			return (T)bitmapToGray(input,(GrayU8)output,storage);
  		else
  			throw new IllegalArgumentException("Unsupported BoofCV Image Type");
  		
  	}