python rgb转整数 如何在Python中将RGB转换为CMYK和反之亦然？

If I had a RGB decimal such as 255, 165, 0, what could I do to convert this to CMYK?

For example:

>>> red, green, blue = 255, 165, 0

>>> rgb_to_cmyk(red, green, blue)

(0, 35, 100, 0)

解决方案

Here's a Python port of a Javascript implementation.

cmyk_scale = 100

def rgb_to_cmyk(r,g,b):

if (r == 0) and (g == 0) and (b == 0):

# black

return 0, 0, 0, cmyk_scale

# rgb [0,255] -> cmy [0,1]

c = 1 - r / 255.

m = 1 - g / 255.

y = 1 - b / 255.

# extract out k [0,1]

min_cmy = min(c, m, y)

c = (c - min_cmy) / (1 - min_cmy)

m = (m - min_cmy) / (1 - min_cmy)

y = (y - min_cmy) / (1 - min_cmy)

k = min_cmy

# rescale to the range [0,cmyk_scale]

return c*cmyk_scale, m*cmyk_scale, y*cmyk_scale, k*cmyk_scale