将RGB颜色转换为HSB颜色

Question

我正在尝试将HSB颜色转换为RGB。我这样做的方式是

System.Windows.Media.Color winColor = value;
System.Drawing.Color drawColor = System.Drawing.Color.FromArgb(winColor.R, winColor.G, winColor.B);
Hue = (byte)(drawColor.GetHue()*255);
Saturation = (byte)(drawColor.GetSaturation()*255);
Luminosity = (byte)(drawColor.GetBrightness()*255);

我发现当我有FF0000的时候，它会被转换成H = 0, S = 255, L = 127，再转换成RGB FF0E0E。我想光度应该是120？还是说我把整个HSB的事情搞错了？当我在Photoshop中查看颜色选择器时，色调为0-360度，饱和度，亮度为0-100%。我的HSB值从0到255，我做错了吗？

Answer 1

此works...modified来自Java源代码。另一个答案仍然是HSL，这实际上是HSB到RGB (实际上是HSB/HSV到System.Windows.Media.Color作为我的返回类型)

    public static Color HSBtoRGB(float hue, float saturation, float brightness)
    {
        int r = 0, g = 0, b = 0;
        if (saturation == 0)
        {
            r = g = b = (int)(brightness * 255.0f + 0.5f);
        }
        else
        {
            float h = (hue - (float)Math.Floor(hue)) * 6.0f;
            float f = h - (float)Math.Floor(h);
            float p = brightness * (1.0f - saturation);
            float q = brightness * (1.0f - saturation * f);
            float t = brightness * (1.0f - (saturation * (1.0f - f)));
            switch ((int)h)
            {
                case 0:
                    r = (int)(brightness * 255.0f + 0.5f);
                    g = (int)(t * 255.0f + 0.5f);
                    b = (int)(p * 255.0f + 0.5f);
                    break;
                case 1:
                    r = (int)(q * 255.0f + 0.5f);
                    g = (int)(brightness * 255.0f + 0.5f);
                    b = (int)(p * 255.0f + 0.5f);
                    break;
                case 2:
                    r = (int)(p * 255.0f + 0.5f);
                    g = (int)(brightness * 255.0f + 0.5f);
                    b = (int)(t * 255.0f + 0.5f);
                    break;
                case 3:
                    r = (int)(p * 255.0f + 0.5f);
                    g = (int)(q * 255.0f + 0.5f);
                    b = (int)(brightness * 255.0f + 0.5f);
                    break;
                case 4:
                    r = (int)(t * 255.0f + 0.5f);
                    g = (int)(p * 255.0f + 0.5f);
                    b = (int)(brightness * 255.0f + 0.5f);
                    break;
                case 5:
                    r = (int)(brightness * 255.0f + 0.5f);
                    g = (int)(p * 255.0f + 0.5f);
                    b = (int)(q * 255.0f + 0.5f);
                    break;
            }
        }
        return Color.FromArgb(Convert.ToByte(255), Convert.ToByte(r), Convert.ToByte(g), Convert.ToByte(b));
    }

Answer 2

由于其他答案似乎对我不起作用(而且我也没有耐心看到发生了什么)，我将我的代码分享给HSV->RGB转换。它基于Wikipedia上的“交替HSV转换”一节，非常紧凑。

public static Color FromAhsv(byte alpha, float hue, float saturation, float value)
{
    if (hue < 0f || hue > 360f)
        throw new ArgumentOutOfRangeException(nameof(hue), hue, "Hue must be in the range [0,360]");
    if (saturation < 0f || saturation > 1f)
        throw new ArgumentOutOfRangeException(nameof(saturation), saturation, "Saturation must be in the range [0,1]");
    if (value < 0f || value > 1f)
        throw new ArgumentOutOfRangeException(nameof(value), value, "Value must be in the range [0,1]");

    int Component(int n)
    {
        var k = (n + hue / 60f) % 6;
        var c = value - value * saturation * Math.Max(Math.Min(Math.Min(k, 4 - k), 1), 0);
        var b = (int)Math.Round(c * 255);
        return b < 0 ? 0 : b > 255 ? 255 : b;
    }

    return Color.FromArgb(alpha, Component(5), Component(3), Component(1));
}