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Diffstat (limited to 'libs/canvas/colorspace.cc')
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diff --git a/libs/canvas/colorspace.cc b/libs/canvas/colorspace.cc deleted file mode 100644 index 50cbac8fb1..0000000000 --- a/libs/canvas/colorspace.cc +++ /dev/null @@ -1,940 +0,0 @@ -/** - * @file colorspace.c - * @author Pascal Getreuer 2005-2010 <getreuer@gmail.com> - * - * == Summary == - * This file implements routines for color transformations between the spaces - * sRGB, Y'UV, Y'CbCr, Y'PbPr, Y'DbDr, Y'IQ, HSV, HSL, HSI, CIEXYZ, CIELAB, - * CIELUV, CIELCH, and CIECAT02 LMS. - * - * == Usage == - * First call GetColorTransform, specifying the source and destination color - * spaces as "dest<-src" or "src->dest". Then call ApplyColorTransform to - * perform the transform: -@code - double S[3] = {173, 0.8, 0.5}; - double D[3]; - colortransform Trans; - - if(!(GetColorTransform(&Trans, "HSI -> Lab"))) - { - printf("Invalid syntax or unknown color space\n"); - return; - } - - ApplyColorTransform(Trans, &D[0], &D[1], &D[2], S[0], S[1], S[2]); -@endcode - * "num" is a typedef defined at the beginning of colorspace.h that may be set - * to either double or float, depending on the application. - * - * Specific transformation routines can also be called directly. The following - * converts an sRGB color to CIELAB and then back to sRGB: -@code - double R = 0.85, G = 0.32, B = 0.5; - double L, a, b; - Rgb2Lab(&L, &a, &b, R, G, B); - Lab2Rgb(&R, &G, &B, L, a, b); -@endcode - * Generally, the calling syntax is -@code - Foo2Bar(&B0, &B1, &B2, F0, F1, F2); -@endcode - * where (F0,F1,F2) are the coordinates of a color in space "Foo" and - * (B0,B1,B2) are the transformed coordinates in space "Bar." For any - * transformation routine, its inverse has the sytax -@code - Bar2Foo(&F0, &F1, &F2, B0, B1, B2); -@endcode - * - * The conversion routines are consistently named with the first letter of a - * color space capitalized with following letters in lower case and omitting - * prime symbols. For example, "Rgb2Ydbdr" converts sRGB to Y'DbDr. For - * any transformation routine Foo2Bar, its inverse is Bar2Foo. - * - * All transformations assume a two degree observer angle and a D65 illuminant. - * The white point can be changed by modifying the WHITEPOINT_X, WHITEPOINT_Y, - * WHITEPOINT_Z definitions at the beginning of colorspace.h. - * - * == List of transformation routines == - * - Rgb2Yuv(double *Y, double *U, double *V, double R, double G, double B) - * - Rgb2Ycbcr(double *Y, double *Cb, double *Cr, double R, double G, double B) - * - Rgb2Jpegycbcr(double *Y, double *Cb, double *Cr, double R, double G, double B) - * - Rgb2Ypbpr(double *Y, double *Pb, double *Pr, double R, double G, double B) - * - Rgb2Ydbdr(double *Y, double *Db, double *Dr, double R, double G, double B) - * - Rgb2Yiq(double *Y, double *I, double *Q, double R, double G, double B) - * - Rgb2Hsv(double *H, double *S, double *V, double R, double G, double B) - * - Rgb2Hsl(double *H, double *S, double *L, double R, double G, double B) - * - Rgb2Hsi(double *H, double *S, double *I, double R, double G, double B) - * - Rgb2Xyz(double *X, double *Y, double *Z, double R, double G, double B) - * - Xyz2Lab(double *L, double *a, double *b, double X, double Y, double Z) - * - Xyz2Luv(double *L, double *u, double *v, double X, double Y, double Z) - * - Xyz2Lch(double *L, double *C, double *h, double X, double Y, double Z) - * - Xyz2Cat02lms(double *L, double *M, double *S, double X, double Y, double Z) - * - Rgb2Lab(double *L, double *a, double *b, double R, double G, double B) - * - Rgb2Luv(double *L, double *u, double *v, double R, double G, double B) - * - Rgb2Lch(double *L, double *C, double *h, double R, double G, double B) - * - Rgb2Cat02lms(double *L, double *M, double *S, double R, double G, double B) - * (Similarly for the inverse transformations.) - * - * It is possible to transform between two arbitrary color spaces by first - * transforming from the source space to sRGB and then transforming from - * sRGB to the desired destination space. For transformations between CIE - * color spaces, it is convenient to use XYZ as the intermediate space. This - * is the strategy used by GetColorTransform and ApplyColorTransform. - * - * == References == - * The definitions of these spaces and the many of the transformation formulas - * can be found in - * - * Poynton, "Frequently Asked Questions About Gamma" - * http://www.poynton.com/notes/colour_and_gamma/GammaFAQ.html - * - * Poynton, "Frequently Asked Questions About Color" - * http://www.poynton.com/notes/colour_and_gamma/ColorFAQ.html - * - * and Wikipedia articles - * http://en.wikipedia.org/wiki/SRGB - * http://en.wikipedia.org/wiki/YUV - * http://en.wikipedia.org/wiki/YCbCr - * http://en.wikipedia.org/wiki/YPbPr - * http://en.wikipedia.org/wiki/YDbDr - * http://en.wikipedia.org/wiki/YIQ - * http://en.wikipedia.org/wiki/HSL_and_HSV - * http://en.wikipedia.org/wiki/CIE_1931_color_space - * http://en.wikipedia.org/wiki/Lab_color_space - * http://en.wikipedia.org/wiki/CIELUV_color_space - * http://en.wikipedia.org/wiki/LMS_color_space - * - * == License (BSD) == - * Copyright (c) 2005-2010, Pascal Getreuer - * All rights reserved. - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions are met: - * - * - Redistributions of source code must retain the above copyright - * notice, this list of conditions and the following disclaimer. - * - Redistributions in binary form must reproduce the above copyright - * notice, this list of conditions and the following disclaimer in - * the documentation and/or other materials provided with the distribution. - * - * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" - * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE - * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE - * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE - * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR - * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF - * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS - * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN - * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) - * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE - * POSSIBILITY OF SUCH DAMAGE. - */ -#include <math.h> -#include <stdio.h> -#include <string.h> -#include <ctype.h> - -#include "canvas/colorspace.h" - -/** @brief Min of A and B */ -#define MIN(A,B) (((A) <= (B)) ? (A) : (B)) - -/** @brief Max of A and B */ -#define MAX(A,B) (((A) >= (B)) ? (A) : (B)) - -/** @brief Min of A, B, and C */ -#define MIN3(A,B,C) (((A) <= (B)) ? MIN(A,C) : MIN(B,C)) - -/** @brief Max of A, B, and C */ -#define MAX3(A,B,C) (((A) >= (B)) ? MAX(A,C) : MAX(B,C)) - -#ifndef M_PI -/** @brief The constant pi */ -#define M_PI 3.14159265358979323846264338327950288 -#endif - -/** - * @brief sRGB gamma correction, transforms R to R' - * http://en.wikipedia.org/wiki/SRGB - */ -#define GAMMACORRECTION(t) \ - (((t) <= 0.0031306684425005883) ? \ - (12.92*(t)) : (1.055*pow((t), 0.416666666666666667) - 0.055)) - -/** - * @brief Inverse sRGB gamma correction, transforms R' to R - */ -#define INVGAMMACORRECTION(t) \ - (((t) <= 0.0404482362771076) ? \ - ((t)/12.92) : pow(((t) + 0.055)/1.055, 2.4)) - -/** - * @brief CIE L*a*b* f function (used to convert XYZ to L*a*b*) - * http://en.wikipedia.org/wiki/Lab_color_space - */ -#define LABF(t) \ - ((t >= 8.85645167903563082e-3) ? \ - pow(t,0.333333333333333) : (841.0/108.0)*(t) + (4.0/29.0)) - -/** - * @brief CIE L*a*b* inverse f function - * http://en.wikipedia.org/wiki/Lab_color_space - */ -#define LABINVF(t) \ - ((t >= 0.206896551724137931) ? \ - ((t)*(t)*(t)) : (108.0/841.0)*((t) - (4.0/29.0))) - -/** @brief u'v' coordinates of the white point for CIE Lu*v* */ -#define WHITEPOINT_U ((4*WHITEPOINT_X) \ - /(WHITEPOINT_X + 15*WHITEPOINT_Y + 3*WHITEPOINT_Z)) -#define WHITEPOINT_V ((9*WHITEPOINT_Y) \ - /(WHITEPOINT_X + 15*WHITEPOINT_Y + 3*WHITEPOINT_Z)) - -/** @brief Enumeration of the supported color spaces */ -#define UNKNOWN_SPACE 0 -#define RGB_SPACE 1 -#define YUV_SPACE 2 -#define YCBCR_SPACE 3 -#define JPEGYCBCR_SPACE 4 -#define YPBPR_SPACE 5 -#define YDBDR_SPACE 6 -#define YIQ_SPACE 7 -#define HSV_SPACE 8 -#define HSL_SPACE 9 -#define HSI_SPACE 10 -#define XYZ_SPACE 11 -#define LAB_SPACE 12 -#define LUV_SPACE 13 -#define LCH_SPACE 14 -#define CAT02LMS_SPACE 15 - -#define NUM_TRANSFORM_PAIRS 18 - - - -/* - * == Linear color transformations == - * - * The following routines implement transformations between sRGB and - * the linearly-related color spaces Y'UV, Y'PbPr, Y'DbDr, and Y'IQ. - */ - - -/** - * @brief Convert sRGB to NTSC/PAL Y'UV Luma + Chroma - * - * @param Y, U, V pointers to hold the result - * @param R, G, B the input sRGB values - * - * Wikipedia: http://en.wikipedia.org/wiki/YUV - */ -void Rgb2Yuv(double *Y, double *U, double *V, double R, double G, double B) -{ - *Y = (double)( 0.299*R + 0.587*G + 0.114*B); - *U = (double)(-0.147*R - 0.289*G + 0.436*B); - *V = (double)( 0.615*R - 0.515*G - 0.100*B); -} - - -/** - * @brief Convert NTSC/PAL Y'UV to sRGB - * - * @param R, G, B pointers to hold the result - * @param Y, U, V the input YUV values - */ -void Yuv2Rgb(double *R, double *G, double *B, double Y, double U, double V) -{ - *R = (double)(Y - 3.945707070708279e-05*U + 1.1398279671717170825*V); - *G = (double)(Y - 0.3946101641414141437*U - 0.5805003156565656797*V); - *B = (double)(Y + 2.0319996843434342537*U - 4.813762626262513e-04*V); -} - - -/** @brief sRGB to Y'CbCr Luma + Chroma */ -void Rgb2Ycbcr(double *Y, double *Cb, double *Cr, double R, double G, double B) -{ - *Y = (double)( 65.481*R + 128.553*G + 24.966*B + 16); - *Cb = (double)(-37.797*R - 74.203*G + 112.0 *B + 128); - *Cr = (double)(112.0 *R - 93.786*G - 18.214*B + 128); -} - - -/** @brief Y'CbCr to sRGB */ -void Ycbcr2Rgb(double *R, double *G, double *B, double Y, double Cr, double Cb) -{ - Y -= 16; - Cb -= 128; - Cr -= 128; - *R = (double)(0.00456621004566210107*Y + 1.1808799897946415e-09*Cr + 0.00625892896994393634*Cb); - *G = (double)(0.00456621004566210107*Y - 0.00153632368604490212*Cr - 0.00318811094965570701*Cb); - *B = (double)(0.00456621004566210107*Y + 0.00791071623355474145*Cr + 1.1977497040190077e-08*Cb); -} - - -/** @brief sRGB to JPEG-Y'CbCr Luma + Chroma */ -void Rgb2Jpegycbcr(double *Y, double *Cb, double *Cr, double R, double G, double B) -{ - Rgb2Ypbpr(Y, Cb, Cr, R, G, B); - *Cb += (double)0.5; - *Cr += (double)0.5; -} - -/** @brief JPEG-Y'CbCr to sRGB */ -void Jpegycbcr2Rgb(double *R, double *G, double *B, double Y, double Cb, double Cr) -{ - Cb -= (double)0.5; - Cr -= (double)0.5; - Ypbpr2Rgb(R, G, B, Y, Cb, Cr); -} - - -/** @brief sRGB to Y'PbPr Luma (ITU-R BT.601) + Chroma */ -void Rgb2Ypbpr(double *Y, double *Pb, double *Pr, double R, double G, double B) -{ - *Y = (double)( 0.299 *R + 0.587 *G + 0.114 *B); - *Pb = (double)(-0.1687367*R - 0.331264*G + 0.5 *B); - *Pr = (double)( 0.5 *R - 0.418688*G - 0.081312*B); -} - - -/** @brief Y'PbPr to sRGB */ -void Ypbpr2Rgb(double *R, double *G, double *B, double Y, double Pb, double Pr) -{ - *R = (double)(0.99999999999914679361*Y - 1.2188941887145875e-06*Pb + 1.4019995886561440468*Pr); - *G = (double)(0.99999975910502514331*Y - 0.34413567816504303521*Pb - 0.71413649331646789076*Pr); - *B = (double)(1.00000124040004623180*Y + 1.77200006607230409200*Pb + 2.1453384174593273e-06*Pr); -} - - -/** @brief sRGB to SECAM Y'DbDr Luma + Chroma */ -void Rgb2Ydbdr(double *Y, double *Db, double *Dr, double R, double G, double B) -{ - *Y = (double)( 0.299*R + 0.587*G + 0.114*B); - *Db = (double)(-0.450*R - 0.883*G + 1.333*B); - *Dr = (double)(-1.333*R + 1.116*G + 0.217*B); -} - - -/** @brief SECAM Y'DbDr to sRGB */ -void Ydbdr2Rgb(double *R, double *G, double *B, double Y, double Db, double Dr) -{ - *R = (double)(Y + 9.2303716147657e-05*Db - 0.52591263066186533*Dr); - *G = (double)(Y - 0.12913289889050927*Db + 0.26789932820759876*Dr); - *B = (double)(Y + 0.66467905997895482*Db - 7.9202543533108e-05*Dr); -} - - -/** @brief sRGB to NTSC YIQ */ -void Rgb2Yiq(double *Y, double *I, double *Q, double R, double G, double B) -{ - *Y = (double)(0.299 *R + 0.587 *G + 0.114 *B); - *I = (double)(0.595716*R - 0.274453*G - 0.321263*B); - *Q = (double)(0.211456*R - 0.522591*G + 0.311135*B); -} - - -/** @brief Convert NTSC YIQ to sRGB */ -void Yiq2Rgb(double *R, double *G, double *B, double Y, double I, double Q) -{ - *R = (double)(Y + 0.9562957197589482261*I + 0.6210244164652610754*Q); - *G = (double)(Y - 0.2721220993185104464*I - 0.6473805968256950427*Q); - *B = (double)(Y - 1.1069890167364901945*I + 1.7046149983646481374*Q); -} - - - -/* - * == Hue Saturation Value/Lightness/Intensity color transformations == - * - * The following routines implement transformations between sRGB and - * color spaces HSV, HSL, and HSI. - */ - - -/** - * @brief Convert an sRGB color to Hue-Saturation-Value (HSV) - * - * @param H, S, V pointers to hold the result - * @param R, G, B the input sRGB values scaled in [0,1] - * - * This routine transforms from sRGB to the hexcone HSV color space. The - * sRGB values are assumed to be between 0 and 1. The output values are - * H = hexagonal hue angle (0 <= H < 360), - * S = C/V (0 <= S <= 1), - * V = max(R',G',B') (0 <= V <= 1), - * where C = max(R',G',B') - min(R',G',B'). The inverse color transformation - * is given by Hsv2Rgb. - * - * Wikipedia: http://en.wikipedia.org/wiki/HSL_and_HSV - */ -void Rgb2Hsv(double *H, double *S, double *V, double R, double G, double B) -{ - double Max = MAX3(R, G, B); - double Min = MIN3(R, G, B); - double C = Max - Min; - - - *V = Max; - - if(C > 0) - { - if(Max == R) - { - *H = (G - B) / C; - - if(G < B) - *H += 6; - } - else if(Max == G) - *H = 2 + (B - R) / C; - else - *H = 4 + (R - G) / C; - - *H *= 60; - *S = C / Max; - } - else - *H = *S = 0; -} - - -/** - * @brief Convert a Hue-Saturation-Value (HSV) color to sRGB - * - * @param R, G, B pointers to hold the result - * @param H, S, V the input HSV values - * - * The input values are assumed to be scaled as - * 0 <= H < 360, - * 0 <= S <= 1, - * 0 <= V <= 1. - * The output sRGB values are scaled between 0 and 1. This is the inverse - * transformation of Rgb2Hsv. - * - * Wikipedia: http://en.wikipedia.org/wiki/HSL_and_HSV - */ -void Hsv2Rgb(double *R, double *G, double *B, double H, double S, double V) -{ - double C = S * V; - double Min = V - C; - double X; - - - H -= 360*floor(H/360); - H /= 60; - X = C*(1 - fabs(H - 2*floor(H/2) - 1)); - - switch((int)H) - { - case 0: - *R = Min + C; - *G = Min + X; - *B = Min; - break; - case 1: - *R = Min + X; - *G = Min + C; - *B = Min; - break; - case 2: - *R = Min; - *G = Min + C; - *B = Min + X; - break; - case 3: - *R = Min; - *G = Min + X; - *B = Min + C; - break; - case 4: - *R = Min + X; - *G = Min; - *B = Min + C; - break; - case 5: - *R = Min + C; - *G = Min; - *B = Min + X; - break; - default: - *R = *G = *B = 0; - } -} - - -/** - * @brief Convert an sRGB color to Hue-Saturation-Lightness (HSL) - * - * @param H, S, L pointers to hold the result - * @param R, G, B the input sRGB values scaled in [0,1] - * - * This routine transforms from sRGB to the double hexcone HSL color space - * The sRGB values are assumed to be between 0 and 1. The outputs are - * H = hexagonal hue angle (0 <= H < 360), - * S = { C/(2L) if L <= 1/2 (0 <= S <= 1), - * { C/(2 - 2L) if L > 1/2 - * L = (max(R',G',B') + min(R',G',B'))/2 (0 <= L <= 1), - * where C = max(R',G',B') - min(R',G',B'). The inverse color transformation - * is given by Hsl2Rgb. - * - * Wikipedia: http://en.wikipedia.org/wiki/HSL_and_HSV - */ -void Rgb2Hsl(double *H, double *S, double *L, double R, double G, double B) -{ - double Max = MAX3(R, G, B); - double Min = MIN3(R, G, B); - double C = Max - Min; - - - *L = (Max + Min)/2; - - if(C > 0) - { - if(Max == R) - { - *H = (G - B) / C; - - if(G < B) - *H += 6; - } - else if(Max == G) - *H = 2 + (B - R) / C; - else - *H = 4 + (R - G) / C; - - *H *= 60; - *S = (*L <= 0.5) ? (C/(2*(*L))) : (C/(2 - 2*(*L))); - } - else - *H = *S = 0; -} - - -/** - * @brief Convert a Hue-Saturation-Lightness (HSL) color to sRGB - * - * @param R, G, B pointers to hold the result - * @param H, S, L the input HSL values - * - * The input values are assumed to be scaled as - * 0 <= H < 360, - * 0 <= S <= 1, - * 0 <= L <= 1. - * The output sRGB values are scaled between 0 and 1. This is the inverse - * transformation of Rgb2Hsl. - * - * Wikipedia: http://en.wikipedia.org/wiki/HSL_and_HSV - */ -void Hsl2Rgb(double *R, double *G, double *B, double H, double S, double L) -{ - double C = (L <= 0.5) ? (2*L*S) : ((2 - 2*L)*S); - double Min = L - 0.5*C; - double X; - - - H -= 360*floor(H/360); - H /= 60; - X = C*(1 - fabs(H - 2*floor(H/2) - 1)); - - switch((int)H) - { - case 0: - *R = Min + C; - *G = Min + X; - *B = Min; - break; - case 1: - *R = Min + X; - *G = Min + C; - *B = Min; - break; - case 2: - *R = Min; - *G = Min + C; - *B = Min + X; - break; - case 3: - *R = Min; - *G = Min + X; - *B = Min + C; - break; - case 4: - *R = Min + X; - *G = Min; - *B = Min + C; - break; - case 5: - *R = Min + C; - *G = Min; - *B = Min + X; - break; - default: - *R = *G = *B = 0; - } -} - - -/** - * @brief Convert an sRGB color to Hue-Saturation-Intensity (HSI) - * - * @param H, S, I pointers to hold the result - * @param R, G, B the input sRGB values scaled in [0,1] - * - * This routine transforms from sRGB to the cylindrical HSI color space. The - * sRGB values are assumed to be between 0 and 1. The output values are - * H = polar hue angle (0 <= H < 360), - * S = 1 - min(R',G',B')/I (0 <= S <= 1), - * I = (R'+G'+B')/3 (0 <= I <= 1). - * The inverse color transformation is given by Hsi2Rgb. - * - * Wikipedia: http://en.wikipedia.org/wiki/HSL_and_HSV - */ -void Rgb2Hsi(double *H, double *S, double *I, double R, double G, double B) -{ - double alpha = 0.5*(2*R - G - B); - double beta = 0.866025403784439*(G - B); - - - *I = (R + G + B)/3; - - if(*I > 0) - { - *S = 1 - MIN3(R,G,B) / *I; - *H = atan2(beta, alpha)*(180/M_PI); - - if(*H < 0) - *H += 360; - } - else - *H = *S = 0; -} - - -/** - * @brief Convert a Hue-Saturation-Intesity (HSI) color to sRGB - * - * @param R, G, B pointers to hold the result - * @param H, S, I the input HSI values - * - * The input values are assumed to be scaled as - * 0 <= H < 360, - * 0 <= S <= 1, - * 0 <= I <= 1. - * The output sRGB values are scaled between 0 and 1. This is the inverse - * transformation of Rgb2Hsi. - * - * Wikipedia: http://en.wikipedia.org/wiki/HSL_and_HSV - */ -void Hsi2Rgb(double *R, double *G, double *B, double H, double S, double I) -{ - H -= 360*floor(H/360); - - if(H < 120) - { - *B = I*(1 - S); - *R = I*(1 + S*cos(H*(M_PI/180))/cos((60 - H)*(M_PI/180))); - *G = 3*I - *R - *B; - } - else if(H < 240) - { - H -= 120; - *R = I*(1 - S); - *G = I*(1 + S*cos(H*(M_PI/180))/cos((60 - H)*(M_PI/180))); - *B = 3*I - *R - *G; - } - else - { - H -= 240; - *G = I*(1 - S); - *B = I*(1 + S*cos(H*(M_PI/180))/cos((60 - H)*(M_PI/180))); - *R = 3*I - *G - *B; - } -} - - -/* - * == CIE color transformations == - * - * The following routines implement transformations between sRGB and - * the CIE color spaces XYZ, L*a*b, L*u*v*, and L*C*H*. These - * transforms assume a 2 degree observer angle and a D65 illuminant. - */ - - -/** - * @brief Transform sRGB to CIE XYZ with the D65 white point - * - * @param X, Y, Z pointers to hold the result - * @param R, G, B the input sRGB values - * - * Poynton, "Frequently Asked Questions About Color," page 10 - * Wikipedia: http://en.wikipedia.org/wiki/SRGB - * Wikipedia: http://en.wikipedia.org/wiki/CIE_1931_color_space - */ -void Rgb2Xyz(double *X, double *Y, double *Z, double R, double G, double B) -{ - R = INVGAMMACORRECTION(R); - G = INVGAMMACORRECTION(G); - B = INVGAMMACORRECTION(B); - *X = (double)(0.4123955889674142161*R + 0.3575834307637148171*G + 0.1804926473817015735*B); - *Y = (double)(0.2125862307855955516*R + 0.7151703037034108499*G + 0.07220049864333622685*B); - *Z = (double)(0.01929721549174694484*R + 0.1191838645808485318*G + 0.9504971251315797660*B); -} - - -/** - * @brief Transform CIE XYZ to sRGB with the D65 white point - * - * @param R, G, B pointers to hold the result - * @param X, Y, Z the input XYZ values - * - * Official sRGB specification (IEC 61966-2-1:1999) - * Poynton, "Frequently Asked Questions About Color," page 10 - * Wikipedia: http://en.wikipedia.org/wiki/SRGB - * Wikipedia: http://en.wikipedia.org/wiki/CIE_1931_color_space - */ -void Xyz2Rgb(double *R, double *G, double *B, double X, double Y, double Z) -{ - double R1, B1, G1, Min; - - - R1 = (double)( 3.2406*X - 1.5372*Y - 0.4986*Z); - G1 = (double)(-0.9689*X + 1.8758*Y + 0.0415*Z); - B1 = (double)( 0.0557*X - 0.2040*Y + 1.0570*Z); - - Min = MIN3(R1, G1, B1); - - /* Force nonnegative values so that gamma correction is well-defined. */ - if(Min < 0) - { - R1 -= Min; - G1 -= Min; - B1 -= Min; - } - - /* Transform from RGB to R'G'B' */ - *R = GAMMACORRECTION(R1); - *G = GAMMACORRECTION(G1); - *B = GAMMACORRECTION(B1); -} - - -/** - * Convert CIE XYZ to CIE L*a*b* (CIELAB) with the D65 white point - * - * @param L, a, b pointers to hold the result - * @param X, Y, Z the input XYZ values - * - * Wikipedia: http://en.wikipedia.org/wiki/Lab_color_space - */ -void Xyz2Lab(double *L, double *a, double *b, double X, double Y, double Z) -{ - X /= WHITEPOINT_X; - Y /= WHITEPOINT_Y; - Z /= WHITEPOINT_Z; - X = LABF(X); - Y = LABF(Y); - Z = LABF(Z); - *L = 116*Y - 16; - *a = 500*(X - Y); - *b = 200*(Y - Z); -} - - -/** - * Convert CIE L*a*b* (CIELAB) to CIE XYZ with the D65 white point - * - * @param X, Y, Z pointers to hold the result - * @param L, a, b the input L*a*b* values - * - * Wikipedia: http://en.wikipedia.org/wiki/Lab_color_space - */ -void Lab2Xyz(double *X, double *Y, double *Z, double L, double a, double b) -{ - L = (L + 16)/116; - a = L + a/500; - b = L - b/200; - *X = WHITEPOINT_X*LABINVF(a); - *Y = WHITEPOINT_Y*LABINVF(L); - *Z = WHITEPOINT_Z*LABINVF(b); -} - - -/** - * Convert CIE XYZ to CIE L*u*v* (CIELUV) with the D65 white point - * - * @param L, u, v pointers to hold the result - * @param X, Y, Z the input XYZ values - * - * Wikipedia: http://en.wikipedia.org/wiki/CIELUV_color_space - */ -void Xyz2Luv(double *L, double *u, double *v, double X, double Y, double Z) -{ - double u1, v1, Denom; - - - if((Denom = X + 15*Y + 3*Z) > 0) - { - u1 = (4*X) / Denom; - v1 = (9*Y) / Denom; - } - else - u1 = v1 = 0; - - Y /= WHITEPOINT_Y; - Y = LABF(Y); - *L = 116*Y - 16; - *u = 13*(*L)*(u1 - WHITEPOINT_U); - *v = 13*(*L)*(v1 - WHITEPOINT_V); -} - - -/** - * Convert CIE L*u*v* (CIELUV) to CIE XYZ with the D65 white point - * - * @param X, Y, Z pointers to hold the result - * @param L, u, v the input L*u*v* values - * - * Wikipedia: http://en.wikipedia.org/wiki/CIELUV_color_space - */ -void Luv2Xyz(double *X, double *Y, double *Z, double L, double u, double v) -{ - *Y = (L + 16)/116; - *Y = WHITEPOINT_Y*LABINVF(*Y); - - if(L != 0) - { - u /= L; - v /= L; - } - - u = u/13 + WHITEPOINT_U; - v = v/13 + WHITEPOINT_V; - *X = (*Y) * ((9*u)/(4*v)); - *Z = (*Y) * ((3 - 0.75*u)/v - 5); -} - - -/** - * Convert CIE XYZ to CIE L*C*H* with the D65 white point - * - * @param L, C, H pointers to hold the result - * @param X, Y, Z the input XYZ values - * - * CIE L*C*H* is related to CIE L*a*b* by - * a* = C* cos(H* pi/180), - * b* = C* sin(H* pi/180). - */ -void Xyz2Lch(double *L, double *C, double *H, double X, double Y, double Z) -{ - double a, b; - - - Xyz2Lab(L, &a, &b, X, Y, Z); - *C = sqrt(a*a + b*b); - *H = atan2(b, a)*180.0/M_PI; - - if(*H < 0) - *H += 360; -} - -/** - * Convert CIE L*C*H* to CIE XYZ with the D65 white point - * - * @param X, Y, Z pointers to hold the result - * @param L, C, H the input L*C*H* values - */ -void Lch2Xyz(double *X, double *Y, double *Z, double L, double C, double H) -{ - double a = C * cos(H*(M_PI/180.0)); - double b = C * sin(H*(M_PI/180.0)); - - - Lab2Xyz(X, Y, Z, L, a, b); -} - - -/** @brief XYZ to CAT02 LMS */ -void Xyz2Cat02lms(double *L, double *M, double *S, double X, double Y, double Z) -{ - *L = (double)( 0.7328*X + 0.4296*Y - 0.1624*Z); - *M = (double)(-0.7036*X + 1.6975*Y + 0.0061*Z); - *S = (double)( 0.0030*X + 0.0136*Y + 0.9834*Z); -} - - -/** @brief CAT02 LMS to XYZ */ -void Cat02lms2Xyz(double *X, double *Y, double *Z, double L, double M, double S) -{ - *X = (double)( 1.096123820835514*L - 0.278869000218287*M + 0.182745179382773*S); - *Y = (double)( 0.454369041975359*L + 0.473533154307412*M + 0.072097803717229*S); - *Z = (double)(-0.009627608738429*L - 0.005698031216113*M + 1.015325639954543*S); -} - - -/* - * == Glue functions for multi-stage transforms == - */ - -void Rgb2Lab(double *L, double *a, double *b, double R, double G, double B) -{ - double X, Y, Z; - Rgb2Xyz(&X, &Y, &Z, R, G, B); - Xyz2Lab(L, a, b, X, Y, Z); -} - - -void Lab2Rgb(double *R, double *G, double *B, double L, double a, double b) -{ - double X, Y, Z; - Lab2Xyz(&X, &Y, &Z, L, a, b); - Xyz2Rgb(R, G, B, X, Y, Z); -} - - -void Rgb2Luv(double *L, double *u, double *v, double R, double G, double B) -{ - double X, Y, Z; - Rgb2Xyz(&X, &Y, &Z, R, G, B); - Xyz2Luv(L, u, v, X, Y, Z); -} - - -void Luv2Rgb(double *R, double *G, double *B, double L, double u, double v) -{ - double X, Y, Z; - Luv2Xyz(&X, &Y, &Z, L, u, v); - Xyz2Rgb(R, G, B, X, Y, Z); -} - -void Rgb2Lch(double *L, double *C, double *H, double R, double G, double B) -{ - double X, Y, Z; - Rgb2Xyz(&X, &Y, &Z, R, G, B); - Xyz2Lch(L, C, H, X, Y, Z); -} - - -void Lch2Rgb(double *R, double *G, double *B, double L, double C, double H) -{ - double X, Y, Z; - Lch2Xyz(&X, &Y, &Z, L, C, H); - Xyz2Rgb(R, G, B, X, Y, Z); -} - - -void Rgb2Cat02lms(double *L, double *M, double *S, double R, double G, double B) -{ - double X, Y, Z; - Rgb2Xyz(&X, &Y, &Z, R, G, B); - Xyz2Cat02lms(L, M, S, X, Y, Z); -} - - -void Cat02lms2Rgb(double *R, double *G, double *B, double L, double M, double S) -{ - double X, Y, Z; - Cat02lms2Xyz(&X, &Y, &Z, L, M, S); - Xyz2Rgb(R, G, B, X, Y, Z); -} |