Go 我相信我正确地在 sRGB 和线性 RGB 之间进行了转换，那么为什么深色的结果看起来更糟呢

在研究了the Wikipedia entry on sRGB个之后，我实现了一组函数来帮助进行 colored颜色 转换:

import "math"

// https://en.wikipedia.org/wiki/SRGB#Transformation

var byteDecoded [256]float32 = func() (floats [256]float32) {
    for i := 0; i < 256; i++ {
        floats[i] = float32(i) / 255
    }
    return floats
}()

// Standard returns the sRGB color space value in range [0.0-1.0] for v, assuming v is in linear RGB in range [0.0-1.0].
func Standard(v float32) float32 {
    if v <= 0.0031308 {
        return v * 12.92
    }
    return float32(1.055*math.Pow(float64(v), 1.0/2.4) - 0.055)
}

// Standardb returns the sRGB color space value in range [0-255] for v, assuming v is in linear RGB in range [0.0-1.0].
func Standardb(v float32) uint8 {
    if v >= 1 {
        return 255
    }
    if v <= 0 {
        return 0
    }
    return uint8(Standard(v)*255 + 0.5)
}

// Linear returns the linear RGB color space value in range [0.0-1.0] for v, assuming v is in sRGB in range [0.0-1.0].
func Linear(v float32) float32 {
    if v <= 0.04045 {
        return v * (1.0 / 12.92)
    }
    return float32(math.Pow((float64(v)+0.055)/1.055, 2.4))
}

// Linearb returns the linear RGB color space value in range [0.0-1.0] for b, assuming b is in sRGB in range [0-255].
func Linearb(b uint8) float32 {
    return Linear(byteDecoded[b])
}

然后我玩了一些结果.

log.Printf("Half of sRGB 255 calculated in linear RGB is %d", Standardb(Linearb(255)/2))
prints Half of sRGB 255 calculated in linear RGB is 188.

然后我做了这个:

Top half: checkerboarded red (255, 0, 0) and green (0, 255, 0) pixels.
Lower left: naive mixdown by division with 2 (128, 128, 0).
Lower right: (188, 188, 0)

下半部分显示了上半部分在两个轴上缩小50%时的两种不同try .由于上半部分是全绿色和全红色像素的交错，缩小比例必须将半红色和半绿色相加在一起，其值是我之前计算的(188).

右下角与我的普通消费者显示器上的上半部分非常匹配，所以看起来整个转换数学都解决了.

但深色又如何呢？

log.Printf("Half of sRGB 64 calculated in linear RGB is %d", Standardb(Linearb(64)/2))
prints Half of sRGB 64 calculated in linear RGB is 44.

我做的和以前一样:

Top half: checkerboarded dark red (64, 0, 0) and dark green (0, 64, 0) pixels.
Lower left: naive mixdown by division with 2 (32, 32, 0).
Lower right: (44, 44, 0)

这一次，在我的显示器上，朴素(不正确)的方法与上半部分几乎完美匹配，而我在右下角努力计算的值看起来太亮了.

我是不是搞错了？或者，这只是消费者显示设备上预期的错误程度？