如何在pygame中制作Surface的灰度副本？

Question

在pygame中,我有一个表面:

im = pygame.image.load('foo.png').convert_alpha()
im = pygame.transform.scale(im, (64, 64))

如何获取图像的灰度副本,或将图像数据转换为灰度？我有笨蛋.

Answer 1

使用Surfarray,并使用numpy或Numeric过滤它:

def grayscale(self, img):
    arr = pygame.surfarray.array3d(img)
    #luminosity filter
    avgs = [[(r*0.298 + g*0.587 + b*0.114) for (r,g,b) in col] for col in arr]
    arr = numpy.array([[[avg,avg,avg] for avg in col] for col in avgs])
    return pygame.surfarray.make_surface(arr)