def to_grayscale_depth(self):
        """ Converts to a grayscale and depth (G-D) image. """
        gray = self.color.to_grayscale()
        return GdImage.from_grayscale_and_depth(gray, self.depth)
def to_grayscale_depth ( self ) : gray = self . color . to_grayscale ( ) return GdImage . from_grayscale_and_depth ( gray , self . depth )
Converts to a grayscale and depth (G-D) image.