如何将RGB颜色更改为HSV？

Question

如何将RGB颜色更改为HSV？在C#语言中.我没有任何外部库搜索非常快的方法.

Answer 1

注意Color.GetSaturation()并Color.GetBrightness()返回HSL值,而不是HSV.
以下代码演示了不同之处.

Color original = Color.FromArgb(50, 120, 200);
// original = {Name=ff3278c8, ARGB=(255, 50, 120, 200)}

double hue;
double saturation;
double value;
ColorToHSV(original, out hue, out saturation, out value);
// hue        = 212.0
// saturation = 0.75
// value      = 0.78431372549019607

Color copy = ColorFromHSV(hue, saturation, value);
// copy = {Name=ff3278c8, ARGB=(255, 50, 120, 200)}

// Compare that to the HSL values that the .NET framework provides: 
original.GetHue();        // 212.0
original.GetSaturation(); // 0.6
original.GetBrightness(); // 0.490196079

以下C#代码就是您想要的.它使用维基百科上描述的算法在RGB和HSV之间进行转换.范围为0 - 360表示hue,0 - 1表示saturation或value.

public static void ColorToHSV(Color color, out double hue, out double saturation, out double value)
{
    int max = Math.Max(color.R, Math.Max(color.G, color.B));
    int min = Math.Min(color.R, Math.Min(color.G, color.B));

    hue = color.GetHue();
    saturation = (max == 0) ? 0 : 1d - (1d * min / max);
    value = max / 255d;
}

public static Color ColorFromHSV(double hue, double saturation, double value)
{
    int hi = Convert.ToInt32(Math.Floor(hue / 60)) % 6;
    double f = hue / 60 - Math.Floor(hue / 60);

    value = value * 255;
    int v = Convert.ToInt32(value);
    int p = Convert.ToInt32(value * (1 - saturation));
    int q = Convert.ToInt32(value * (1 - f * saturation));
    int t = Convert.ToInt32(value * (1 - (1 - f) * saturation));

    if (hi == 0)
        return Color.FromArgb(255, v, t, p);
    else if (hi == 1)
        return Color.FromArgb(255, q, v, p);
    else if (hi == 2)
        return Color.FromArgb(255, p, v, t);
    else if (hi == 3)
        return Color.FromArgb(255, p, q, v);
    else if (hi == 4)
        return Color.FromArgb(255, t, p, v);
    else
        return Color.FromArgb(255, v, p, q);
}

Answer 2

您是否考虑过简单地使用System.Drawing命名空间？例如:

System.Drawing.Color color = System.Drawing.Color.FromArgb(red, green, blue);
float hue = color.GetHue();
float saturation = color.GetSaturation();
float lightness = color.GetBrightness();

请注意,这并不是您所要求的(请参阅HSL和HSV之间的差异,而Color类没有从HSL/HSV转换回来,但后者相当容易添加.

Answer 3

该EasyRGB有很多色彩空间转换。这是RGB->HSV 转换的代码。

Answer 4

这里有一个C实现:

http://www.cs.rit.edu/~ncs/color/t_convert.html

转换为C#应该非常简单,因为几乎没有函数被调用 - 只是计算.

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