c# - 如何将 RGB 颜色转换为 HSV？

Question

如何使用 C# 将 RGB 颜色转换为 HSV？
我在不使用任何外部库的情况下搜索了一种快速方法。

score 114 · Accepted Answer

请注意Color.GetSaturation()并Color.GetBrightness()返回 HSL 值，而不是 HSV。
下面的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# 代码是您想要的。它使用Wikipedia上描述的算法在 RGB 和 HSV 之间进行转换。范围为 0 - 360hue和 0 - 1 为saturationor 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);
}

score 26 · Accepted Answer

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，这并不完全符合您的要求（请参阅HSL 和 HSV 之间的差异，并且 Color 类没有从 HSL/HSV 转换回来，但后者相当容易添加.

score 6 · Accepted Answer

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，因为几乎没有调用任何函数 - 只是计算。

通过谷歌找到

score 6 · Accepted Answer

6

EasyRGB有许多色彩空间转换。这是RGB->HSV 转换的代码。

于 2012-10-09T21:45:58.197 回答

score 3 · Accepted Answer

这是从 BlaM 帖子中的 C 代码移植的 VB.net 版本，对我来说效果很好。

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，因为几乎没有调用任何函数 - 只是 > 计算。

Public Sub HSVtoRGB(ByRef r As Double, ByRef g As Double, ByRef b As Double, ByVal h As Double, ByVal s As Double, ByVal v As Double)
    Dim i As Integer
    Dim f, p, q, t As Double

    If (s = 0) Then
        ' achromatic (grey)
        r = v
        g = v
        b = v
        Exit Sub
    End If

    h /= 60 'sector 0 to 5
    i = Math.Floor(h)
    f = h - i 'factorial part of h
    p = v * (1 - s)
    q = v * (1 - s * f)
    t = v * (1 - s * (1 - f))

    Select Case (i)
        Case 0
            r = v
            g = t
            b = p
            Exit Select
        Case 1
            r = q
            g = v
            b = p
            Exit Select
        Case 2
            r = p
            g = v
            b = t
            Exit Select
        Case 3
            r = p
            g = q
            b = v
            Exit Select
        Case 4
            r = t
            g = p
            b = v
            Exit Select
        Case Else   'case 5:
            r = v
            g = p
            b = q
            Exit Select
    End Select
End Sub

score 0 · Accepted Answer

I've ended up here by having the same need.

Bellow I'm sharing the best and simpler solution I could find so far.
This is a modified answer from Greg's (found here); but with a humbler and understandable code.

For those who are learning I've added a few references that are worth checking for the sake of understanding.

References

Code

    /// <summary> Convert RGB Color to HSV. </summary>
    /// <param name="color"></param>
    /// <returns> A double[] Containing HSV Color Values. </returns>
    public double[] rgbToHSV(Color color)
    {
        double[] output = new double[3];

        double hue, saturation, 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;

        output[0] = hue;
        output[1] = saturation;
        output[2] = value;

        return output;
    }

score -1 · Accepted Answer

第一：确保你有一个颜色作为位图，像这样：

Bitmap bmp = (Bitmap)pictureBox1.Image.Clone();
paintcolor = bmp.GetPixel(e.X, e.Y);

（e 来自事件处理程序，它选择了我的颜色！）

What I did when I had this problem a whilke ago, I first got the rgba (red, green, blue and alpha) values. Next I created 3 floats: float hue, float saturation, float brightness. Then you simply do:

hue = yourcolor.Gethue;
saturation = yourcolor.GetSaturation;
brightness = yourcolor.GetBrightness;

The whole lot looks like this:

Bitmap bmp = (Bitmap)pictureBox1.Image.Clone();
            paintcolor = bmp.GetPixel(e.X, e.Y);
            float hue;
            float saturation;
            float brightness;
            hue = paintcolor.GetHue();
            saturation = paintcolor.GetSaturation();
            brightness = paintcolor.GetBrightness();

If you now want to display them in a label, just do:

yourlabelname.Text = hue.ToString;
yourlabelname.Text = saturation.ToString;
yourlabelname.Text = brightness.ToString;

Here you go, you now have RGB Values into HSV values :)

Hope this helps

c# - 如何将 RGB 颜色转换为 HSV？

7 回答 7

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