【C#】RGB,CMYK,HSB各种颜色表示的转换

ゝ一世哀愁。 2022-04-10 09:13 365阅读 0赞

一、表示颜色的方式有很多种，如RGB，CMYK，HSB，Hex等等

1、RGB：这种表示颜色由三原色构成，通过红，绿，蓝三种颜色分量的不同，组合成不同的颜色，例如，100%红+100%绿混合可以得到黄色，红绿蓝三种颜色叠加可以得到白色，基本上屏幕显示色彩都采用这种方式

![06142205-6dcc78f5159c4c88a5c2689b99e6b6b4.png][]

2、CMYK：也称作印刷色彩模式，是一种依靠反光的色彩模式，主要用于印刷，和RGB类似，CMY是3种印刷油墨名称的首字母：青色Cyan、品红色Magenta、黄色Yellow。而K取的是black最后一个字母，之所以不取首字母，是为了避免与蓝色(Blue)混淆。从理论上来说，只需要CMY三种油墨就足够了，它们三个加在一起就应该得到黑色。但是由于目前制造工艺还不能造出高纯度的油墨，CMY相加的结果实际是一种暗红色。

![06142533-b3aa61d06f25476582ce109c9e7b0274.png][]

3、HSB：通过色相（hues），饱和度（saturation），亮度（brightness）来表示颜色

![06142658-0ad3cc21914749cd975f509c9baca4f5.png][]

二、下面说说关于各种颜色之间的转换

1、RGB与CMYK之间的转换

public static void RGB2CMYK(int red, int green, int blue, out double c, out double m, out double y, out double k)
            {
                c = (double)(255 - red) / 255;
                m = (double)(255 - green) / 255;
                y = (double)(255 - blue) / 255;
    
                k = (double)Math.Min(c, Math.Min(m, y));
                if (k == 1.0)
                {
                    c = m = y = 0;
                }
                else
                {
                    c = (c - k) / (1 - k);
                    m = (m - k) / (1 - k);
                    y = (y - k) / (1 - k);
                }
            }
            public static void CMYK2RGB(double c, double m, double y, double k, out int r, out int g, out int b)
            {
                r = Convert.ToInt32((1.0 - c) * (1.0 - k) * 255.0);
                g = Convert.ToInt32((1.0 - m) * (1.0 - k) * 255.0);
                b = Convert.ToInt32((1.0 - y) * (1.0 - k) * 255.0);
            }

2、RGB与HSB之间的转换

public static void RGB2HSB(int red, int green, int blue, out double hue, out double sat, out double bri)
            {
                double r = ((double)red / 255.0);
                double g = ((double)green / 255.0);
                double b = ((double)blue / 255.0);
    
                double max = Math.Max(r, Math.Max(g, b));
                double min = Math.Min(r, Math.Min(g, b));
    
                hue = 0.0;
                if (max == r && g >= b)
                {
                    if (max - min == 0) hue = 0.0;
                    else hue = 60 * (g - b) / (max - min);
                }
                else if (max == r && g < b)
                {
                    hue = 60 * (g - b) / (max - min) + 360;
                }
                else if (max == g)
                {
                    hue = 60 * (b - r) / (max - min) + 120;
                }
                else if (max == b)
                {
                    hue = 60 * (r - g) / (max - min) + 240;
                }
    
                sat = (max == 0) ? 0.0 : (1.0 - ((double)min / (double)max));
                bri = max;
            }
            public static void HSB2RGB(double hue, double sat, double bri, out int red, out int green ,out int blue)
            {
                double r = 0;
                double g = 0;
                double b = 0;
    
                if (sat == 0)
                {
                    r = g = b = bri;
                }
                else
                {
                    // the color wheel consists of 6 sectors. Figure out which sector you're in.
                    double sectorPos = hue / 60.0;
                    int sectorNumber = (int)(Math.Floor(sectorPos));
                    // get the fractional part of the sector
                    double fractionalSector = sectorPos - sectorNumber;
    
                    // calculate values for the three axes of the color. 
                    double p = bri * (1.0 - sat);
                    double q = bri * (1.0 - (sat * fractionalSector));
                    double t = bri * (1.0 - (sat * (1 - fractionalSector)));
    
                    // assign the fractional colors to r, g, and b based on the sector the angle is in.
                    switch (sectorNumber)
                    {
                        case 0:
                            r = bri;
                            g = t;
                            b = p;
                            break;
                        case 1:
                            r = q;
                            g = bri;
                            b = p;
                            break;
                        case 2:
                            r = p;
                            g = bri;
                            b = t;
                            break;
                        case 3:
                            r = p;
                            g = q;
                            b = bri;
                            break;
                        case 4:
                            r = t;
                            g = p;
                            b = bri;
                            break;
                        case 5:
                            r = bri;
                            g = p;
                            b = q;
                            break;
                    }
                }
                red = Convert.ToInt32(r * 255);
                green = Convert.ToInt32(g * 255);
                blue = Convert.ToInt32(b * 255); ;
            }

3、RGB与十六进制Hex表示的转换

public static string RGB2Hex(int r, int g, int b)
            {
                return String.Format("#{0:x2}{1:x2}{2:x2}", (int)r, (int)g, (int)b);
            }
            public static Color Hex2Color(string hexColor)
            {
                string r, g, b;
    
                if (hexColor != String.Empty)
                {
                    hexColor = hexColor.Trim();
                    if (hexColor[0] == '#') hexColor = hexColor.Substring(1, hexColor.Length - 1);
    
                    r = hexColor.Substring(0, 2);
                    g = hexColor.Substring(2, 2);
                    b = hexColor.Substring(4, 2);
    
                    r = Convert.ToString(16 * GetIntFromHex(r.Substring(0, 1)) + GetIntFromHex(r.Substring(1, 1)));
                    g = Convert.ToString(16 * GetIntFromHex(g.Substring(0, 1)) + GetIntFromHex(g.Substring(1, 1)));
                    b = Convert.ToString(16 * GetIntFromHex(b.Substring(0, 1)) + GetIntFromHex(b.Substring(1, 1)));
    
                    return Color.FromArgb(Convert.ToInt32(r), Convert.ToInt32(g), Convert.ToInt32(b));
                }
    
                return Color.Empty;
            }
            private static int GetIntFromHex(string strHex)
            {
                switch (strHex)
                {
                    case ("A"):
                        {
                            return 10;
                        }
                    case ("B"):
                        {
                            return 11;
                        }
                    case ("C"):
                        {
                            return 12;
                        }
                    case ("D"):
                        {
                            return 13;
                        }
                    case ("E"):
                        {
                            return 14;
                        }
                    case ("F"):
                        {
                            return 15;
                        }
                    default:
                        {
                            return int.Parse(strHex);
                        }
                }
            }

转换算法摘自：[http://www.codeproject.com/Articles/19045/Manipulating-colors-in-NET-Part-1][http_www.codeproject.com_Articles_19045_Manipulating-colors-in-NET-Part-1]

[06142205-6dcc78f5159c4c88a5c2689b99e6b6b4.png]: /images/20220401/8412afe2359a4bff8dae3e3be564c17b.png
[06142533-b3aa61d06f25476582ce109c9e7b0274.png]: /images/20220401/b4b0375f440f4294bf2fd7448becc83b.png
[06142658-0ad3cc21914749cd975f509c9baca4f5.png]: /images/20220401/6d6c4c6fee1e475fa565bd2170d80e42.png
[http_www.codeproject.com_Articles_19045_Manipulating-colors-in-NET-Part-1]: http://www.codeproject.com/Articles/19045/Manipulating-colors-in-NET-Part-1