Convert RGB <-> YUV

rgb_yuv.py

def rgb_y(r, g, b):
    return ((66 * r + 129 * g + 25 * b + 128) >> 8) + 16

def rgb_u(r, g, b):
    return ((-38 * r - 74 * g + 112 * b + 128) >> 8) + 128

def rgb_v(r, g, b):
    return ((112 * r - 94 * g - 18 * b + 128) >> 8) + 128

def yuv_r(y, u, v):
    r = (298 * (y - 16) + 409 * (v - 128) + 128) >> 8

    return min(max(0, r), 255)

def yuv_g(y, u, v):
    g = (298 * (y - 16) - 100 * (u - 128) - 208 * (v - 128) + 128) >> 8

    return min(max(0, g), 255)

def yuv_b(y, u, v):
    b = (298 * (y - 16) + 516 * (u - 128) + 128) >> 8

    return min(max(0, b), 255)

r = 190
g = 0
b = 0

y = rgb_y(r, g, b)
u = rgb_u(r, g, b)
v = rgb_v(r, g, b)

print("RGB({}, {}, {}) -> YUV({}, {}, {})".format(r, g, b, y, u, v))

r = yuv_r(y, u, v)
g = yuv_g(y, u, v)
b = yuv_b(y, u, v)

print("YUV({}, {}, {}) -> RGB({}, {}, {})".format(y, u, v, r, g, b))