docs: public static <In extends ImageGray,Out extends ImageGray>
  	Out checkDeclare(In input, Out output , Class<Out> typeOut) {
  		if (output == null) {
  			output = (Out) GeneralizedImageOps.createSingleBand(typeOut, input.width, input.height);
  		} else {
  			output.reshape(input.width, input.height);
  		}
  		return output;
  	}