第2章颜色空间变换 (征求意见稿) 清华大学计算机科学与技术系 智能技术与系统国家重点实验室 林福宗 2001年10月20日 附录:部分颜色空间转换参考程序 1.RGB和HSV 2.HLS/HSB和RGB 3.HSI和RGB 4. CIE XYZ和 CIELAB 5. CIE XYZ和RGB 1.RGB和HSV RGB→HsV ①执行RGB→HSⅤ( Travis)算法的C++参考程序 本客幸客水凇涂*称水客水客水水客 s Written by: Christopher Aagaard Course: CIS 540-Software Engineering Project I This is an alternate RGB to hsv conversion function ightly different algor *http://www.realtime.ru/wwwboard/messages/120.html * (note that if s=0, H is undefined and set to O) #include <math. h> /*here for compilation purposes only */ / here for compilation purposes only*/ int main(void)(retum 0 double*rgb2hsvALT(double *rgb)i double *hsy= new double double R, G, B double H, s, v 1
1 第 2 章 颜色空间变换 (征求意见稿) 清华大学计算机科学与技术系 智能技术与系统国家重点实验室 林福宗 2001 年 10 月 20 日 附录：部分颜色空间转换参考程序 1. RGB 和 HSV 2. HLS/HSB 和 RGB 3. HSI 和 RGB 4. CIE XYZ 和 CIELAB 5. CIE XYZ 和 RGB --------------------------------------------------------- 1. RGB 和 HSV (1) RGB→HSV ① 执行 RGB→HSV(Travis)算法的 C++参考程序 /************************************************* * Written by: Christopher Aagaard * Course: CIS 540 - Software Engineering Project 1 * * This is an alternate RGB to HSV conversion function. * It uses a slightly different algorithm from: * http://www.realtime.ru/wwwboard/messages/120.html * (Travis) * (note that if S=0, H is undefined and set to 0) */ #include <math.h> /*here for compilation purposes only*/ int main(void){return 0;} /* here for compilation purposes only*/ int main(void){return 0;} double* rgb2hsvALT(double *rgb) { double *hsv = new double[3]; double R, G, B; double R1, G1, B1; double H, S, V;
R=rgb[0 G=rgb(1: B-rgb[21 if( max<G)(max=G; i if( max<B)(max=B; I if(min>G)(min=; if(min>B)(min=B j if( max! =0)(S=delta/max; i if(S==0)(H=0; /*H is undefined"/ if(delta!=0)( RI=( GI=(max-G)/delta Bl=(max-B)/delta else(RI=Gl=bl=0; if(r==max & G==min)(H=5+Bl else if(R==max & Gl=min)(HI-Gl else if(G-max & B=min)(H=RI+; else if (G==max & B!=min)(H=3-Bl else if(R==max)(H3+GI else(H=5-Rl; /*converts to degrees so S and V are on the range [0, 1] *and H is on the range [0, 360]. */ HH*60 hsv[o=H hsv[l]=S; hsv[2]=V; return hsy. ②执行RGB→HSⅤ( Foley and vanDam)算法的C++参考程序 /*****本**本****幸********家***幸****亲幸本 Converts a rgb value to a hsv value Takes an array of length 3 containing RGB values s Returns an array of lenght 3 containing the converted HSV values 2
2 double max, min, delta; R=rgb[0]; G=rgb[1]; B=rgb[2]; max=R; if(max<G) {max=G;} if(max<B) {max=B;} min=R; if(min>G) {min=G;} if(min>B) {min=B;} delta=max-min; V=max; if(max!=0) {S=delta/max;} else{S=0;} if(S==0) {H=0;} /*H is undefined*/ else { if(delta!=0) { R1=(max-R)/delta; G1=(max-G)/delta; B1=(max-B)/delta; } else{R1=G1=B1=0;} } if(R==max && G==min) {H=5+B1;} else if (R==max && G!=min) {H=1-G1;} else if (G==max && B==min) {H=R1+1;} else if (G==max && B!=min) {H=3-B1;} else if (R==max) {H=3+G1;} else {H=5-R1;} /*converts to degrees so S and V are on the range [0,1] *and H is on the range [0,360].*/ H=H*60; hsv[0]=H; hsv[1]=S; hsv[2]=V; return hsv; } ② 执行 RGB→HSV (Foley and VanDam)算法的 C++参考程序 /********************************************************** * Converts a RGB value to a HSV value. * Takes an array of length 3 containing RGB values. * Returns an array of lenght 3 containing the converted HSV values
*H- between 0 and 360 (if s=0, H is undefined) * v- between 0 and 1 Algorithm translated to c++ from http://www.realtime.ru/wwwboard/messages/120.html * Foley and VanDam #include <math. h> rgb2hsw( double *rgb)( double * hsv new double 31 double H,S, V double max; /*max of RGB* double min: /min of rGB* double delta:/ R=rgb[0]: G=rgb[1]: B-rgb(2] R if( B max)(max=B n=R: if(G<min)(min=G if( B<min)(min=B; j if( max I=0)(S=(max-min)/max, i if(S==0)(H=0; /undefined* if(max=R)(H(G-B)/delta, 3 if( max=G)(H2+(B-R)/delta if( max-B)(H4+(R-G)/delta, H=H60 ifH<0){HH360;} v[]=H; hsv[l]=S; hsv(2]=V, return hsy: (引自:htp/www.cis.ksuedu/-steam200
3 * H - between 0 and 360 (if S=0, H is undefined) * S - between 0 and 1 * V - between 0 and 1 * * Algorithm translated to C++ from: * http://www.realtime.ru/wwwboard/messages/120.html * (Foley and VanDam) */ #include <math.h> double* rgb2hsv(double *rgb) { double R, G, B; double *hsv = new double[3]; double H, S, V; double max; /*max of RGB*/ double min; /*min of RGB*/ double delta; /*max-min*/ R=rgb[0]; G=rgb[1]; B=rgb[2]; max=R; if(G>max) {max=G;} if(B>max) {max=B;} min=R; if(G<min) {min=G;} if(B<min) {min=B;} V=max; if(max != 0) {S=(max-min)/max;} else {S=0;} if(S == 0) {H=0;} /*undefined*/ else { delta=max-min; if(max==R) {H=(G-B)/delta;} if(max==G) {H=2+(B-R)/delta;} if(max==B) {H=4+(R-G)/delta;} } H=H*60; if(H<0) {H=H+360;} hsv[0]=H; hsv[1]=S; hsv[2]=V; return hsv; } (引自：http://www.cis.ksu.edu/~seteam20/)
(2)HsV→RGB ①执行HSV→RGB( Travis)算法的C++参考程序 /****幸**幸春本****幸本本***春春本本***春本本春率本***幸 This is an alternate conversion of a hsv value to a rgb value s Takes an array of length 3 containing HsV values Returns an array of lenght 3 containing the converted RGB values Algorithm translated to C++ from *http://www.realtime.ru/wwwboard/messages/120.html double* hsv2rgbalT(double * hsv)i double* rgb= new double[31 double H s, v double hex. main colour. sub color double varl. var 2. var3 Hhsvlol: S=hsv[l: V=hsv(21 hex=H/360: /*convert h degrees to a hexagon section * main colour=(int hex sub colour=hex-main colour varl=(l-S)"V var2=(1-(S*sub colour))*V, var3=(1-(S*(l colour)))* if( main colour=0)(R=V, G=var 3: B-var1 if( main colour=1)(R=var 2 G=V B-var1 if( main colour=2)(R=varl; G=V B-var3 if( main colour=3)(R=varl; G=var2, B-V;) main colour- :4)(R=var 3: G=var1; B-V, 3 if( main colour=5)(R=V G=varl: B-var 2: 1 rgb[0]=R; rgb[1=G; rgb[2]=B, return rgb, ②执行HSⅤ→RGB( Foley and VanDam)算法的C++参考程序 称水客客客水客水客*客水*客水***水水客水水*客*客*容水*客水客水客水凇客水客 Converts a hSv value to a rgB value Takes an array of length 3 containing HSV values Returns an array of lenght 3 containing the converted RGB values
4 (2) HSV→RGB ① 执行 HSV→RGB(Travis)算法的 C++参考程序 /************************************************************* * This is an alternate conversion of a HSV value to a RGB value. * Takes an array of length 3 containing HSV values. * Returns an array of lenght 3 containing the converted RGB values. * * Algorithm translated to C++ from: * http://www.realtime.ru/wwwboard/messages/120.html * (Travis) */ double* hsv2rgbALT(double *hsv) { double* rgb = new double[3]; double H, S, V; double R, G, B; double hex, main_colour, sub_colour; double var1, var2, var3; H=hsv[0]; S=hsv[1]; V=hsv[2]; hex=H/360; /*convert H degrees to a hexagon section*/ main_colour=(int)hex; sub_colour=hex-main_colour; var1=(1-S)*V; var2=(1-(S*sub_colour))*V; var3=(1-(S*(1-sub_colour)))*V; if(main_colour==0) {R=V; G=var3; B=var1;} if(main_colour==1) {R=var2; G=V; B=var1;} if(main_colour==2) {R=var1; G=V; B=var3;} if(main_colour==3) {R=var1; G=var2; B=V; } if(main_colour==4) {R=var3; G=var1; B=V; } if(main_colour==5) {R=V; G=var1; B=var2;} rgb[0]=R; rgb[1]=G; rgb[2]=B; return rgb; } ② 执行 HSV→RGB (Foley and VanDam)算法的 C++参考程序 /**************************************************** * Converts a HSV value to a RGB value. * Takes an array of length 3 containing HSV values. * Returns an array of lenght 3 containing the converted RGB values
Algorithm translated to C++ from s/120 htr double rgb= new double[31 double r, g, B, double H s, v ouble i f, p, g, t if(s==0 & H=0)(R=G=B-V; )/*if S=0 and H is undefined*/ ifH=360){H=0; oor(h) p=V(1-S) if(F=0)(R=V, G=t; B-p; i 珉F=1){R=q,G=V,Bp;} 珉F=2){R=p,G=V,B=t} if(F=)(R=p: G=q: B-V, if(F-4)(R=t; G=p: B-V;; if(F=5)(R=V, G=p: B-q) 2.HLS/HSB和RGB **称*客水*客水*客客水水客水*水*水*水*客水**客客水*涂客水水*客*水*客水客水**水客水*水客水*客水*宗*客水农水 The hsl model is in some fashion a boosted hsv model. Even if it's based on the Ostwald system, created around 1930(not sure: maybe it was 1931). It forms a s dodecahedron formed by two Hexcone base to base, with one sharp point black, and s with the other white. IT has some disadvantages since the purity of color not at max value but at its half (=0.5). It makes it a little harder to use with the common 3 axis(sliders if you use Mac or Windows)H, L, S. By the way: H is for Hue, L for lightness. Lightness of 1=white, 0=black and S is still *涂*水*客水容水**水容水*客水*涂**水**客**水*客***客***水水*客**水*水***客水*****幸 function value(nl, n2, hue real): real
5 * Algorithm translated to C++ from: * http://www.realtime.ru/wwwboard/messages/120.html * (Foley and VanDam) */ double* hsv2rgb(double *hsv) { double *rgb = new double[3]; double R, G, B; double H, S, V; double i, f, p, q, t; H=hsv[0]; S=hsv[1]; V=hsv[2]; if(S==0 && H==0) {R=G=B=V;} /*if S=0 and H is undefined*/ if(H==360) {H=0;} H=H/60; i=floor(H); f=H-i; p=V*(1-S); q=V*(1-(S*f)); t=V*(1-(S*(1-f))); if(i==0) {R=V; G=t; B=p;} if(i==1) {R=q; G=V; B=p;} if(i==2) {R=p; G=V; B=t;} if(i==3) {R=p; G=q; B=V;} if(i==4) {R=t; G=p; B=V;} if(i==5) {R=V; G=p; B=q;} rgb[0]=R; rgb[1]=G; rgb[2]=B; return rgb; } 2. HLS/HSB 和 RGB ********************************************************************* * The HSL model is in some fashion a boosted HSV model. Even if it's based on the * Ostwald system, created around 1930 (not sure: maybe it was 1931). It forms a * dodecahedron formed by two Hexcone base to base, with one sharp point black, and * with the other white. IT has some disadvantages since the purity of color is * not at max value but at its half ( = 0.5). It makes it a little harder to use * with the common 3 axis (sliders if you use Mac or Windows) H,L,S. By the way: H * is for Hue, L for lightness. Lightness of 1=white, 0=black and S is still * saturation. ********************************************************************* function value(n1,n2,hue :real) : real;