code: public static GrayU16 convert(GrayF32 input, GrayU16 output) {
  		if (output == null) {
  			output = new GrayU16(input.width, input.height);
  		} else {
  			output.reshape(input.width,input.height);
  		}
  
  		// threaded code is not significantly faster here
  		ImplConvertImage.convert(input, output);
  
  		return output;
  	}
docs: <p>
  Converts an {@link boofcv.struct.image.GrayF32} into a {@link boofcv.struct.image.GrayU16}.
  </p>
  
  @param input Input image which is being converted. Not modified.
  @param output (Optional) The output image.  If null a new image is created. Modified.
  @return Converted image.