mitkColorConversions.cpp
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00001 /*========================================================================= 00002 00003 Program: Medical Imaging & Interaction Toolkit 00004 Language: C++ 00005 Date: $Date$ 00006 Version: $Revision$ 00007 00008 Copyright (c) German Cancer Research Center, Division of Medical and 00009 Biological Informatics. All rights reserved. 00010 See MITKCopyright.txt or https://www.mitk.org/copyright.html for details. 00011 00012 This software is distributed WITHOUT ANY WARRANTY; without even 00013 the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR 00014 PURPOSE. See the above copyright notices for more information. 00015 00016 =========================================================================*/ 00017 00018 #include<mitkColorConversions.h> 00019 00020 namespace mitk { 00021 00022 namespace ColorConversions { 00023 00024 /* 00025 Convert HSV color to RGB color (pseudocode from wikipedia) 00026 00027 H from 0 to 360 00028 S from 0 to 1 00029 V from 0 to 1 00030 00031 R, G, and B from 0 to 1 00032 */ 00033 void Hsv2Rgb(float h, float s, float v, float& r, float& g, float& b) 00034 { 00035 if (s == 0.0) 00036 { 00037 r = g = b = v; // gray 00038 return; 00039 } 00040 00041 int Hi = (int)( h / 60.0 ) % 6; 00042 if (h >= 360 ) Hi = 6; 00043 00044 float f = (float)(h / 60.0 - (float)Hi); 00045 float p = (float)(v * (1.0 - s)); 00046 float q = (float)(v * (1.0 - s * f)); 00047 float t = (float)(v * (1.0 - s * (1.0 - f))); 00048 00049 switch (Hi) 00050 { 00051 case 0: case 6: r = v; g = t; b = p; break; 00052 case 1: r = q; g = v; b = p; break; 00053 case 2: r = p; g = v; b = t; break; 00054 case 3: r = p; g = q; b = v; break; 00055 case 4: r = t; g = p; b = v; break; 00056 case 5: r = v; g = p; b = q; break; 00057 } 00058 } 00059 /* 00060 Convert RGB color to HSV color 00061 00062 R from 0 to 1 00063 G from 0 to 1 00064 B from 0 to 1 00065 00066 H from 0 to 360 and -1 for undefined color (pure white) 00067 S from 0 to 1 00068 V from 0 to 1 00069 */ 00070 void Rgb2Hsv(float r, float g, float b, float &h, float &s, float &v) 00071 { 00072 /* r = r/255; 00073 b = b/255; 00074 g = g/255;*/ 00075 00076 float mn=r,mx=r; 00077 int maxVal=0; 00078 00079 if (g > mx){ mx=g;maxVal=1;} 00080 if (b > mx){ mx=b;maxVal=2;} 00081 if (g < mn) mn=g; 00082 if (b < mn) mn=b; 00083 00084 float delta = mx - mn; 00085 00086 v = mx; 00087 if( mx != 0 ) 00088 s = delta / mx; 00089 else 00090 { 00091 s = 0; 00092 h = 0; 00093 return; 00094 } 00095 if (s==0.0f) 00096 { 00097 h=-1; 00098 return; 00099 } 00100 else 00101 { 00102 switch (maxVal) 00103 { 00104 case 0:{h = ( g - b ) / delta;break;} // yel < h < mag 00105 case 1:{h = 2 + ( b - r ) / delta;break;} // cyan < h < yel 00106 case 2:{h = 4 + ( r - g ) / delta;break;} // mag < h < cyan 00107 } 00108 } 00109 00110 h *= 60; 00111 if( h < 0 ) h += 360; 00112 } 00113 00114 } // ColorConversion 00115 00116 } // mitk 00117
