实现灰度值与彩色值之间的相互转化python代码

将RGB转为灰度值：

def rgb_to_gray(r, g, b):
    return 0.2989 * r + 0.5870 * g + 0.1140 * b

将灰度值转为RGB：

def gray_to_rgb(gray):
    return (gray, gray, gray)

将RGB转为HSV：

def rgb_to_hsv(r, g, b):
    r /= 255.0
    g /= 255.0
    b /= 255.0
    cmax = max(r, g, b)
    cmin = min(r, g, b)
    delta = cmax - cmin

    if delta == 0:
        hue = 0
    elif cmax == r:
        hue = ((g - b) / delta) % 6
    elif cmax == g:
        hue = (b - r) / delta + 2
    else:
        hue = (r - g) / delta + 4

    hue = round(hue * 60)

    if hue < 0:
        hue += 360

    saturation = 0 if cmax == 0 else delta / cmax
    value = cmax

    return (hue, saturation, value)

将HSV转为RGB：

def hsv_to_rgb(h, s, v):
    c = v * s
    x = c * (1 - abs((h / 60) % 2 - 1))
    m = v - c

    if h < 60:
        r, g, b = c, x, 0
    elif h < 120:
        r, g, b = x, c, 0
    elif h < 180:
        r, g, b = 0, c, x
    elif h < 240:
        r, g, b = 0, x, c
    elif h < 300:
        r, g, b = x, 0, c
    else:
        r, g, b = c, 0, x

    r, g, b = (r + m) * 255, (g + m) * 255, (b + m) * 255

    return (round(r), round(g), round(b))