Conversion formula between RGB and HSB

let's start by understanding some concepts:1.RGB is an additive color model that mixes different proportions of red/green/blue together to get a new color. The RGB color model is typically represented as:

2.HSB (HSV) expresses color through three elements of hue/saturation/brightness.

H (Hue): Indicates the type of color (for example, red, green, or yellow). The value range is 0-360. Each of these values represents a color.

S (saturation): saturation of the color. from 0 to 1. Sometimes also known as purity. (0 for grayscale, 1 for pure color)

B (brightness or Value): the degree of brightness of the color. from 0 to 1. (0 for Black, 1 for a specific saturation color)

The back address is an online tool for observing RGB to HSB conversions: http://web.bentley.edu/empl/c/ncarter/MA307/color-converter.html

It is convenient to use RGB to represent colors, but the RGB values of the two similar colors may be 108,000 of a difference. Using HSV (hue hue, saturation saturation, Value (brightness) lightness, or HSB) to represent colors is more in line with people's habits.

Conversion of RGB to HSV (HSB):

The conversion of the HSV (HSB) to RGB:

According to the above instructions, there are the following conversion formulas (Java code):

[Java] view Plaincopy

2. public static float[] RGB2HSB (int rgbr, int rgbg, int rgbb) {
4. Assert 0 <= rgbr && rgbr <= 255;
6. Assert 0 <= rgbg && rgbg <= 255;
8. Assert 0 <= rgbb && rgbb <= 255;
10. int[] RGB = new int[] {rgbr, RGBG, RGBB};
12. Arrays.sort (RGB);
14. int max = rgb[2];
16. int min = rgb[0];
20. float HSBB = max/255.0f;
22. float Hsbs = max = = 0? 0: (max-min)/(float) max;
26. float HSBH = 0;
28. if (max = = Rgbr && rgbg >= rgbb) {
30. HSBH = (RGBG-RGBB) * 60f/(Max-min) + 0;
32. } else if (max = = Rgbr && RGBG < RGBB) {
34. HSBH = (RGBG-RGBB) * 60f/(max-min) + 360;
36. } else if (max = = RGBG) {
38. HSBH = (RGBB-RGBR) * 60f/(max-min) + 120;
40. } else if (max = = RGBB) {
42. HSBH = (RGBR-RGBG) * 60f/(max-min) + 240;
44. }
48. return new float[] {HSBH, Hsbs, HSBB};
50. }
54. public static int[] Hsb2rgb (float h, float s, float v) {
56. Assert Float.compare (H, 0.0f) >= 0 && Float.compare (H, 360.0f) <= 0;
58. Assert Float.compare (S, 0.0f) >= 0 && Float.compare (S, 1.0f) <= 0;
60. Assert Float.compare (V, 0.0f) >= 0 && float.compare (V, 1.0f) <= 0;
64. float r = 0, g = 0, b = 0;
66. int i = (int) ((H/60)% 6);
68. float f = (h/60)-I;
70. float p = v * (1-s);
72. float q = v * (1-F * s);
74. float T = v * (1-(1-f) * s);
76. switch (i) {
78. Case 0:
80. R = V;
82. g = t;
84. b = P;
86. Break
88. Case 1:
90. R = q;
92. g = V;
94. b = P;
96. Break
98. Case 2:
100. r = P;
102. g = V;
104. b = t;
106. Break
108. Case 3:
110. r = P;
112. g = q;
114. b = V;
116. Break
118. Case 4:
120. R = t;
122. g = P;
124. b = V;
126. Break
128. Case 5:
130. R = V;
132. g = P;
134. b = q;
136. Break
138. Default
140. Break
142. }
144. return new int[] {(int) (R * 255.0), (int) (g * 255.0),
146. (int) (b * 255.0)};
148. }

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Conversion formula between RGB and HSB