c# 颜色RGB到HSB互相转换

Posted 2020-08-28

  1 /// <summary>
  2         /// 色相，饱和度，亮度转换成rgb值
  3         /// </summary>
  4         /// <returns></returns>
  5         public static float[] HSB2RGB(float[] hsb)
  6         {
  7             if (hsb[0] == 360)
  8             {
  9                 hsb[0] = 0;
 10             }
 11             float[] rgb = new float[3];
 12             float r = 0;
 13             float g = 0;
 14             float b = 0;
 15 
 16             if (hsb[1] == 0)
 17             {
 18                 r = g = b = hsb[2];
 19             }
 20             else
 21             {
 22                 float sectorPos = hsb[0] / 60f;
 23                 int sectorNum = (int)Math.Floor(sectorPos);
 24                 float fractionalSector = sectorPos - sectorNum;
 25                 float p = hsb[2] * (1 - hsb[1]);
 26                 float q = hsb[2] * (1 - (hsb[1] * fractionalSector));
 27                 float t = hsb[2] * (1 - (hsb[1] * (1 - fractionalSector)));
 28                 switch (sectorNum)
 29                 {
 30                     case 0:
 31                         r = hsb[2];
 32                         g = t;
 33                         b = p;
 34                         break;
 35                     case 1:
 36                         r = q;
 37                         g = hsb[2];
 38                         b = p;
 39                         break;
 40                     case 2:
 41                         r = p;
 42                         g = hsb[2];
 43                         b = t;
 44                         break;
 45                     case 3:
 46                         r = p;
 47                         g = q;
 48                         b = hsb[2];
 49                         break;
 50                     case 4:
 51                         r = t;
 52                         g = p;
 53                         b = hsb[2];
 54                         break;
 55                     case 5:
 56                         r = hsb[2];
 57                         g = p;
 58                         b = q;
 59                         break;
 60                 }
 61 
 62             }
 63             return new float[] { r * 255, g * 255, b * 255 };
 64         }
 65         /// <summary>
 66         /// 将rgb类型的颜色转换为hsb
 67         /// </summary>
 68         /// <param name="rgb"></param>
 69         /// <returns></returns>
 70         public static float[] RGB2HSB(float[] rgb)
 71         {
 72             float[] hsb = new float[3];
 73             float r = rgb[0];
 74             float g = rgb[1];
 75             float b = rgb[2];
 76 
 77             float max = Math.Max(r, Math.Max(g, b));
 78             if (max <= 0)
 79             {
 80                 return hsb;
 81             }
 82             float min = Math.Min(r, Math.Min(g, b));
 83             float dif = max - min;
 84             if (max > min)
 85             {
 86                 if (g == max)
 87                 {
 88                     hsb[0] = (b - r) / dif * 60f + 120f;
 89                 }
 90                 else if (b == max)
 91                 {
 92                     hsb[0] = (r - g) / dif * 60f + 240f;
 93                 }
 94                 else if (b > g)
 95                 {
 96                     hsb[0] = (g - b) / dif * 60f + 360f;
 97                 }
 98                 else
 99                 {
100                     hsb[0] = (g - b) / dif * 60f;
101                 }
102                 if (hsb[0] < 0)
103                 {
104                     hsb[0] = hsb[0] + 360f;
105                 }
106             }
107             else
108             {
109                 hsb[0] = 0;
110             }
111             hsb[1] = dif / max;
112             hsb[2] = max / 255f;
113             return hsb;
114         }