1.RGB是⼀种加⾊模型,就是将不同⽐例的Red/Green/Blue混合在⼀起得到新颜⾊.通常RGB颜⾊模型表⽰为:
2.HSB(HSV) 通过⾊相/饱和度/亮度三要素来表达颜⾊. H(Hue):表⽰颜⾊的类型(例如红⾊,绿⾊或者黄⾊).取值范围为0—360.其中每⼀个值代表⼀种颜⾊.
S(Saturation):颜⾊的饱和度.从0到1.有时候也称为纯度.(0表⽰灰度图,1表⽰纯的颜⾊)
B(Brightness or Value):颜⾊的明亮程度.从0到1.(0表⽰⿊⾊,1表⽰特定饱和度的颜⾊)
⽤RGB来表⽰颜⾊虽然⽅便,但是两个相近的颜⾊的RGB值却可能相差⼗万⼋千⾥。⽤HSV(Hue⾊相、Saturation饱和度、Value(Brightness)明度,也叫HSB)来表⽰颜⾊就⽐较符合⼈们的习惯。
RGB到HSV(HSB)的转换:
HSV(HSB)到RGB的转换:
根据以上说明,有以下转换公式(Java代码):
[java]
01. public static float[] rgb2hsb(int rgbR, int rgbG, int rgbB) {
02. assert0 <= rgbR && rgbR <= 255;
03. assert0 <= rgbG && rgbG <= 255;
04. assert0 <= rgbB && rgbB <= 255;
05. int[] rgb = new int[] { rgbR, rgbG, rgbB };
06. Arrays.sort(rgb);
07. int max = rgb[2];
08. int min = rgb[0];
09.
代码转换10. float hsbB = max / 255.0f;
11. float hsbS = max == 0 ? 0 : (max - min) / (float) max;
12.
13. float hsbH = 0;
14. if (max == rgbR && rgbG >= rgbB) {
15. hsbH = (rgbG - rgbB) * 60f / (max - min) + 0;
16. } else if (max == rgbR && rgbG < rgbB) {
17. hsbH = (rgbG - rgbB) * 60f / (max - min) + 360;
18. } else if (max == rgbG) {
19. hsbH = (rgbB - rgbR) * 60f / (max - min) + 120;
20. } else if (max == rgbB) {
21. hsbH = (rgbR - rgbG) * 60f / (max - min) + 240;
22. }
23.
24. return new float[] { hsbH, hsbS, hsbB };
25. }
26.
27. public static int[] hsb2rgb(float h, float s, float v) {
28. assert Floatpare(h, 0.0f) >= 0 && Floatpare(h, 360.0f) <= 0;
29. assert Floatpare(s, 0.0f) >= 0 && Floatpare(s, 1.0f) <= 0;
30. assert Floatpare(v, 0.0f) >= 0 && Floatpare(v, 1.0f) <= 0;
31.
32. float r = 0, g = 0, b = 0;
33. int i = (int) ((h / 60) % 6);
34. float f = (h / 60) - i;
35. float p = v * (1 - s);
36. float q = v * (1 - f * s);
37. float t = v * (1 - (1 - f) * s);
38. switch (i) {
39. case0:
40. r = v;
41. g = t;
42. b = p;
43. break;
44. case1:
45. r = q;
46. g = v;
47. b = p;
48. break;
49. case2:
50. r = p;
51. g = v;
52. b = t;
53. break;
54. case3:
55. r = p;
56. g = q;
57. b = v;
58. break;
59. case4:
60. r = t;
61. g = p;
62. b = v;
63. break;
64. case5:
65. r = v;
66. g = p;
67. b = q;
68. break;
69. default:
70. break;
71. }
72. return new int[] { (int) (r * 255.0), (int) (g * 255.0),
73. (int) (b * 255.0) };
01. }
02. 原⽂链接:blog.csdn/xhhjin/article/details/7020449