Mine

	(let (
				(x-pos 0)
				(y-pos 0)
				)
		(while (< x-pos width)
			(while (< y-pos height)
				(if
					(pixels-equal
						image
						drawable
						0 0
						x-pos y-pos
					)
					(gimp-message "equal")
					(gimp-message "not equal")
				)
			)
		)
	)