C# RGB和HSB相互转换

背景

最近做的项目中有这样一个场景，设置任意一种颜色，得到这种颜色偏深和偏浅的两种颜色。也就是说取该颜色同色系的深浅两种颜色。首先想到的是调节透明度，但效果不理想。后来尝试调节颜色亮度，发现这才是正解。但是.NET中不能直接改变Color的亮度，需要将Color转换成HSB模式，然后改变B的值调节亮度。调节亮度后需要再转换成我们熟悉的RGB模式才能使用。下面给出颜色转换方法。

代码

     /// <summary>
     /// 颜色转换帮助类
     /// </summary>
     public class ColorConversionHelper
     {
         /// <summary>
         ///  RGB转HSB
         /// </summary>
         /// <param name="red">红色值</param>
         /// <param name="green">绿色值</param>
         /// <param name="blue">蓝色值</param>
         /// <returns>返回：HSB值集合</returns>
         public static List<float> RGBtoHSB(int red, int green, int blue)
         {
             List<float> hsbList = new List<float>();
             System.Drawing.Color dColor = System.Drawing.Color.FromArgb(red, green, blue);
             hsbList.Add(dColor.GetHue());
             hsbList.Add(dColor.GetSaturation());
             hsbList.Add(dColor.GetBrightness());
             return hsbList;
         }

         /// <summary>
         /// HSB转RGB
         /// </summary>
         /// <param name="hue">色调</param>
         /// <param name="saturation">饱和度</param>
         /// <param name="brightness">亮度</param>
         /// <returns>返回：Color</returns>
         public static Color HSBtoRGB(float hue, float saturation, float brightness)
         {
             int r = , g = , b = ;
             if (saturation == )
             {
                 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 :
                         r = (int)(brightness * 255.0f + 0.5f);
                         g = (int)(t * 255.0f + 0.5f);
                         b = (int)(p * 255.0f + 0.5f);
                         break;
                     case :
                         r = (int)(q * 255.0f + 0.5f);
                         g = (int)(brightness * 255.0f + 0.5f);
                         b = (int)(p * 255.0f + 0.5f);
                         break;
                     case :
                         r = (int)(p * 255.0f + 0.5f);
                         g = (int)(brightness * 255.0f + 0.5f);
                         b = (int)(t * 255.0f + 0.5f);
                         break;
                     case :
                         r = (int)(p * 255.0f + 0.5f);
                         g = (int)(q * 255.0f + 0.5f);
                         b = (int)(brightness * 255.0f + 0.5f);
                         break;
                     case :
                         r = (int)(t * 255.0f + 0.5f);
                         g = (int)(p * 255.0f + 0.5f);
                         b = (int)(brightness * 255.0f + 0.5f);
                         break;
                     case :
                         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(), Convert.ToByte(r), Convert.ToByte(g), Convert.ToByte(b));
         }
     }

扩展阅读

http://stackoverflow.com/questions/4106363/converting-rgb-to-hsb-colors

http://my.oschina.net/soitravel/blog/79862