colorspace.h

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/****************************************************************************
* VCGLib                                                            o o     *
* Visual and Computer Graphics Library                            o     o   *
*                                                                _   O  _   *
* Copyright(C) 2006                                                \/)\/    *
* Visual Computing Lab                                            /\/|      *
* ISTI - Italian National Research Council                           |      *
*                                                                    \      *
* All rights reserved.                                                      *
*                                                                           *
* This program is free software; you can redistribute it and/or modify      *
* it under the terms of the GNU General Public License as published by      *
* the Free Software Foundation; either version 2 of the License, or         *
* (at your option) any later version.                                       *
*                                                                           *
* This program is distributed in the hope that it will be useful,           *
* but WITHOUT ANY WARRANTY; without even the implied warranty of            *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the             *
* GNU General Public License (http://www.gnu.org/licenses/gpl.txt)          *
* for more details.                                                         *
*                                                                           *
****************************************************************************/

#ifndef __VCGLIB_COLORSPACE
#define __VCGLIB_COLORSPACE

#include <vcg/space/color4.h>
#include<algorithm>

namespace vcg
{

template <typename T>
class ColorSpace
{

// definitions
public:

    enum ConeResponse   {       BRADFORD = 0,   VON_KRIES = 1, XYZ_SCALING = 2};

    enum Illuminant
    {
        VCG_ILLUMINANT_A = 0,
        VCG_ILLUMINANT_B = 1,
        VCG_ILLUMINANT_C = 2,
        VCG_ILLUMINANT_D50 = 3,
        VCG_ILLUMINANT_D55 = 4,
        VCG_ILLUMINANT_D65 = 5,
        VCG_ILLUMINANT_D75 = 6,
        VCG_ILLUMINANT_E = 7,
        VCG_ILLUMINANT_INVALID = 8
    };

    enum RGBSpaces
    {
        ADOBE_RGB = 0,
        APPLE_RGB = 1,
        BEST_RGB = 2,
        BETA_RGB = 3,
        BRUCE_RGB = 4,
        CIE_RGB = 5,
        COLOR_MATCH = 6,
        DON_RGB4 = 7,
        ECI_RGB = 8,
        EKTA_SPACE = 9,
        NTSC_RGB = 10,
        PAL_RGB = 11,
        PROPHOTO = 12,
        SMPTE_C = 13,
        SRGB = 14,
        WIDE_GAMUT = 15
    };

// private methods
private:

    static double CIE_EPSILON()
    {
        return 0.008856;  // Intent of the CIE Standard --> 216/24389
    }

    static double CIE_KI()
    {
        return 903.3;     // Intent of the CIE Standard --> 24389/27
    }

    static double RGB2XYZ(int index)
    {
        // RGB WORKING SPACE DATA (RGB TO XYZ CONVERSION MATRIX)
        //
        //  144 elements (16 RGB spaces x matrices of 3 x 3)
        //
        static double RGB_TO_XYZ[]=
        {
            // Adobe RGB (1998)  (ref. D65)
            0.576700, 0.297361,  0.0270328,
            0.185556, 0.627355,  0.0706879,
            0.188212, 0.0752847, 0.991248,

            // Apple RGB  (ref. D65)
            0.449695, 0.244634,  0.0251829,
            0.316251, 0.672034,  0.141184,
            0.18452,  0.0833318, 0.922602,

            // BestRGB  (ref. D50)
            0.632670, 0.228457,  0.000000,
            0.204556, 0.737352,  0.00951424,
            0.126995, 0.0341908, 0.815696,

            // Beta RGB  (ref. D50)
            0.671254, 0.303273,  0.000000,
            0.174583, 0.663786,  0.040701,
            0.118383, 0.0329413, 0.784509,

            // BruceRGB  (ref. D65)
            0.467384, 0.240995,  0.0219086,
            0.294454, 0.683554,  0.0736135,
            0.188629, 0.0754517, 0.993447,

            // CIE  (ref. E)
            0.488718, 0.176204,  0.000000,
            0.310680, 0.812985,  0.0102048,
            0.200602, 0.0108109, 0.989795,

            // ColorMatch  (ref. D50)
            0.509344, 0.274884,  0.0242545,
            0.320907, 0.658132,  0.108782,
            0.133969, 0.0669845, 0.692174,

            // DonRGB4  (ref. D50)
            0.645771,   0.278350,   0.00371134,
            0.193351,   0.687970,   0.0179862,
            0.125098,   0.0336802,  0.803513,

            // ECI  (ref. D50)
            0.650204, 0.320250,  0.000000,
            0.178077, 0.602071,  0.0678390,
            0.135938, 0.0776791, 0.757371,

            // Ekta Space PS5  (ref. D50)
            0.593891,  0.260629,   0.000000,
            0.272980,  0.734946,   0.0419970,
            0.0973486, 0.00442493, 0.783213,

            // NTSC  (ref. C)
            0.606734, 0.298839, 0.000000,
            0.173564, 0.586811, 0.0661196,
            0.200112, 0.114350, 1.11491,

            // PAL / SECAM  (ref. D65)
            0.430587, 0.222021,  0.0201837,
            0.341545, 0.706645,  0.129551,
            0.178336, 0.0713342, 0.939234,

            // ProPhoto  (ref. D50)
            0.797675,  0.288040, 0.000000,
            0.135192,  0.711874, 0.000000,
            0.0313534, 0.000086, 0.825210,

            // SMPTE-C  (ref. D65)
            0.393555, 0.212395,  0.0187407,
            0.365253, 0.701049,  0.111932,
            0.191659, 0.0865558, 0.958297,

            // sRGB  (ref. D65)
            0.412424, 0.212656,  0.0193324,
            0.357579, 0.715158,  0.119193,
            0.180464, 0.0721856, 0.950444,

            // WideGamut  (ref. D50)
            0.716105, 0.258187,  0.000000,
            0.100930, 0.724938,  0.0517813,
            0.147186, 0.0168748, 0.773429

        };

        return RGB_TO_XYZ[index];
    }

    static double XYZ2RGB(int index)
    {
        // RGB WORKING SPACE DATA (XYZ TO RGB CONVERSION MATRIX)
        //
        //  144 elements (16 RGB spaces x matrices of 3 x 3)
        //
        static double XYZ_TO_RGB[]=
        {
            // Adobe RGB (1998)  (ref. D65)
            2.04148,   -0.969258,   0.0134455,
            -0.564977,   1.87599,  -0.118373,
            -0.344713,   0.0415557,  1.01527,

            // Apple RGB  (ref. D65)
            2.95176, -1.0851,   0.0854804,
            -1.28951, 1.99084,  -0.269456,
            -0.47388, 0.0372023,   1.09113,

            // BestRGB  (ref. D50)
            1.75526,  -0.544134,   0.00634681,
            -0.483679, 1.50688,  -0.0175762,
            -0.253000, 0.0215528, 1.22570,

            // Beta RGB  (ref. D50)
            1.68323,   -0.771023, 0.0400012,
            -0.428236, 1.70656,  -0.0885376,
            -0.236018, 0.0446899, 1.27236,

            // BruceRGB  (ref. D65)
            2.74566,  -0.969257,   0.0112707,
            -1.13589,  1.87599,  -0.113959,
            -0.435057, 0.0415557, 1.01311,

            // CIE  (ref. E)
            2.37067,  -0.513885,  0.00529818,
            -0.900040, 1.42530,  -0.0146949,
            -0.470634, 0.0885814, 1.00940,

            // ColorMatch  (ref. D50)
            2.64229,  -1.11198,   0.0821698,
            -1.22343,  2.05902,  -0.280725,
            -0.393014, 0.0159614, 1.45599,

            // DonRGB4  (ref. D50)
            1.76039,  -0.712629,   0.00782072,
            -0.488120, 1.65274,  -0.0347411,
            -0.253613, 0.0416715, 1.24477,

            // ECI  (ref. D50)
            1.78276,   -0.959362,  0.0859318,
            -0.496985,  1.94780,  -0.174467,
            -0.269010, -0.0275807, 1.32283,

            // Ekta Space PS5  (ref. D50)
            2.00438,  -0.711029,   0.0381263,
            -0.730484, 1.62021,  -0.0868780,
            -0.245005,  0.0792227, 1.27254,

            // NTSC  (ref. C)
            1.91049,   -0.984310,  0.0583744,
            -0.532592,  1.99845,  -0.118518,
            -0.288284, -0.0282980, 0.898611,

            // PAL / SECAM  (ref. D65)
            3.06313,   -0.969258,   0.0678674,
            -1.39328,   1.87599,  -0.228821,
            -0.475788,  0.0415557, 1.06919,

            // ProPhoto  (ref. D50)
            1.34594,   -0.544599,   0.000000,
            -0.255608,  1.50817,   0.000000,
            -0.0511118, 0.0205351, 1.21181,

            // SMPTE-C  (ref. D65)
            3.50570,   -1.06906,   0.0563117,
            -1.73964,   1.97781,  -0.196994,
            -0.544011,  0.0351720, 1.05005,

            // sRGB  (ref. D65)
            3.24071,  -0.969258,   0.0556352,
            -1.53726,  1.87599,   -0.203996,
            -0.498571, 0.0415557,  1.05707,

            // WideGamut  (ref. D50)
            1.46281,  -0.521793,   0.0349342,
            -0.184062, 1.44724,   -0.0968931,
            -0.274361, 0.0677228,  1.28841

        };

        return XYZ_TO_RGB[index];
    }

    static double CA(int index)
    {
        // CHROMATIC ADAPTATION MATRIX
        //
        //  196 (8 x 8 illuminants x 3 cone response) matrices of 3 x 3 elements
        //
        static double CAmatrix[]=
        {
            // A -> A
            1.0, 0.0, 0.0,
            0.0, 1.0, 0.0,
            0.0, 0.0, 1.0,

            1.0, 0.0, 0.0,
            0.0, 1.0, 0.0,
            0.0, 0.0, 1.0,

            1.0, 0.0, 0.0,
            0.0, 1.0, 0.0,
            0.0, 0.0, 1.0,

            // A -> B (Bradford)
            0.890600, -0.097037, 0.054012,
            -0.082873, 1.075262, -0.091063,
            0.268563, 0.088084, 2.486772,

            // A -> B (Von Kries)
            0.957515, -0.018042, 0.000000,
            -0.164247, 1.018522, 0.000000,
            0.290746, 0.003635, 2.397466,

            // A -> B (XYZ scaling)
            0.902065, 0.000000, 0.000000,
            0.000000, 1.000000, 0.000000,
            0.000000, 0.000000, 2.397474,

            // A -> C (Bradford)
            0.853036, -0.123884, 0.091195,
            -0.113032, 1.085373, -0.155374,
            0.440458, 0.142587, 3.477780,

            // A -> C (Von Kries)
            0.941839, -0.024699, 0.000000,
            -0.224854, 1.025358,  0.000000,
            0.480676, 0.004974, 3.322435,

            // A -> C (XYZ scaling)
            0.892678, 0.000000, 0.000000,
            0.000000, 1.000000, 0.000000,
            0.000000, 0.000000, 3.322447,

            // A -> D50 (Bradford)
            0.878034, -0.111621, 0.050313,
            -0.091487, 1.092265, -0.083964,
            0.257070, 0.085312, 2.402220,

            // A -> D50 (Von Kries)
            0.953214, -0.019868, 0.000000,
            -0.180875, 1.020397, 0.000000,
            0.276267, 0.004004, 2.321454,

            // A -> D50 (XYZ scaling)
            0.877936, 0.000000, 0.000000,
            0.000000, 1.000000, 0.000000,
            0.000000, 0.000000, 2.321462,

            // A -> D55 (Bradford)
            0.864256, -0.122489, 0.061011,
            -0.102279, 1.098455, -0.102340,
            0.307550, 0.101476, 2.689914,

            // A -> D55 (Von Kries)
            0.947636, -0.022237, 0.000000,
            -0.202440, 1.022829, 0.000000,
            0.331718, 0.004481, 2.590505,

            // A -> D55 (XYZ Scaling)
            0.870670, 0.000000, 0.000000,
            0.000000, 1.000000, 0.000000,
            0.000000, 0.000000, 2.590514,

            // A -> D65 (Bradford)
            0.844763, -0.136524, 0.080011,
            -0.117903, 1.103952, -0.135190,
            0.395490, 0.129376, 3.196569,

            // A -> D65 (Von Kries)
            0.939518, -0.025685, 0.000000,
            -0.233826, 1.026369, 0.000000,
            0.428852, 0.005174, 3.063452,

            // A -> D65 (XYZ Scaling)
            0.865414, 0.000000, 0.000000,
            0.000000, 1.000000, 0.000000,
            0.000000, 0.000000, 3.063462,

            // A -> D75 (Bradford)
            0.830991, -0.145710,  0.095536,
            -0.129133,  1.106062, -0.162123,
            0.466601,  0.151821,  3.608682,

            // A -> D75 (Von Kries)
            0.933660, -0.028172, 0.000000,
            -0.256474, 1.028923, 0.000000,
            0.507632, 0.005674, 3.447762,

            // A -> D75 (XYZ Scaling)
            0.864434,  0.000000,  0.000000,
            0.000000,  1.000000,  0.000000,
            0.000000,  0.000000,  3.447773,

            // A -> E (Bradford)
            0.881682, -0.100560,  0.071051,
            -0.090783,  1.070733, -0.120888,
            0.344476,  0.111711,  2.933736,

            // A -> E (Von Kries)
            0.953314, -0.019826, 0.000000,
            -0.180491, 1.020355, 0.000000,
            0.375531, 0.003993, 2.813168,

            // A -> E (XYZ Scaling)
            0.910515, 0.000000, 0.000000,
            0.000000, 1.000000, 0.000000,
            0.000000, 0.000000, 2.813177,

            // B ->     A (Bradford)
            1.138867,  0.104490, -0.020910,
            0.077128,  0.934300,  0.032538,
            -0.125725, -0.044379,  0.403234,

            // B -> A (Von Kries)
            1.047555, 0.018556, 0.000000,
            0.168937, 0.984806, 0.000000,
            -0.127296, -0.003743, 0.417104,

            // B -> A (XYZ Scaling)
            1.108567, 0.000000, 0.000000,
            0.000000, 1.000000, 0.000000,
            0.000000, 0.000000, 0.417106,

            // B -> B
            1.0, 0.0, 0.0,
            0.0, 1.0, 0.0,
            0.0, 0.0, 1.0,

            1.0, 0.0, 0.0,
            0.0, 1.0, 0.0,
            0.0, 0.0, 1.0,

            1.0, 0.0, 0.0,
            0.0, 1.0, 0.0,
            0.0, 0.0, 1.0,

            // B -> C (Bradford)
            0.950475, -0.030658,  0.014905,
            -0.025481,  1.009149, -0.024973,
            0.075375,  0.024904,  1.397787,

            // B -> C (Von Kries)
            0.982455, -0.006847, 0.000000,
            -0.062331, 1.005606, 0.000000,
            0.081442, 0.001380, 1.385807,

            // B -> C (XYZ Scaling)
            0.989593, 0.000000, 0.000000,
            0.000000, 1.000000, 0.000000,
            0.000000, 0.000000, 1.385811,

            // B -> D50 (Bradford)
            0.985029, -0.014775, -0.001704,
            -0.009391,  1.014671,  0.003596,
            -0.002672, -0.000039,  0.966056,

            // B -> D50 (Von Kries)
            0.995186, -0.001879, 0.000000,
            -0.017098, 1.001537, 0.000000,
            -0.005430, 0.000380, 0.968292,

            // B -> D50 (XYZ Scaling)
            0.973252, 0.000000, 0.000000,
            0.000000, 1.000000, 0.000000,
            0.000000, 0.000000, 0.968295,

            // B -> D55 (Bradford)
            0.967155, -0.026843,  0.002545,
            -0.018894,  1.020141, -0.003387,
            0.019895,  0.007571,  1.081535,

            // B -> D55 (Von Kries)
            0.988943, -0.004315,  0.000000,
            -0.039278, 1.003532,  0.000000,
            0.018490,  0.000871,  1.080514,

            // B -> D55 (XYZ Scaling)
            0.965197, 0.000000, 0.000000,
            0.000000, 1.000000, 0.000000,
            0.000000, 0.000000, 1.080518,

            // B -> D65 (Bradford)
            0.941484, -0.042836,  0.010157,
            -0.032134,  1.025102, -0.016128,
            0.058499,  0.020341,  1.284904,

            // B -> D65 (Von Kries)
            0.979857, -0.007861, 0.000000,
            -0.071558, 1.006436, 0.000000,
            0.060156, 0.001586, 1.277783,

            // B -> D65 (XYZ Scaling)
            0.959370, 0.000000, 0.000000,
            0.000000, 1.000000, 0.000000,
            0.000000, 0.000000, 1.277788,

            // B -> D75 (Bradford)
            0.923139, -0.053546, 0.016407,
            -0.041374, 1.027096, -0.026684,
            0.089403, 0.030453, 1.450325,

            // B -> D75 (Von Kries)
            0.973300, -0.010419, 0.000000,
            -0.094851, 1.008531, 0.000000,
            0.093846, 0.002101, 1.438081,

            // B -> D75 (XYZ Scaling)
            0.958283, 0.000000, 0.000000,
            0.000000, 1.000000, 0.000000,
            0.000000, 0.000000, 1.438086,

            // B -> E (Bradford)
            0.987430, -0.004980, 0.006942,
            -0.005608, 0.996265, -0.012009,
            0.032084, 0.010171, 1.179413,

            // B -> E (Von kries)
            0.995299, -0.001835, 0.000000,
            -0.016702, 1.001503, 0.000000,
            0.035959, 0.000370, 1.173388,

            // B -> E (XYZ Scaling)
            1.009367, 0.000000, 0.000000,
            0.000000, 1.000000, 0.000000,
            0.000000, 0.000000, 1.173392,

            // C ->     A (Bradford)
            1.203987, 0.140744, -0.025283,
            0.102952, 0.928000, 0.038760,
            -0.156705, -0.055873, 0.289153,

            // C -> A (Von Kries)
            1.067896, 0.025724, 0.000000,
            0.234191, 0.980909, 0.000000,
            -0.154849, -0.005190, 0.300982,

            // C -> A (XYZ Scaling)
            1.120225, 0.000000, 0.000000,
            0.000000, 1.000000, 0.000000,
            0.000000, 0.000000, 0.300983,

            // C -> B (Bradford)
            1.053816,   0.032278, -0.010661,
            0.025192,   0.991268,  0.017441,
            -0.057275, -0.019402,  0.715681,

            // C -> B (Von Kries)
            1.018301,   0.006933, 0.000000,
            0.063126,   0.994853, 0.000000,
            -0.059908, -0.001398, 0.721597,

            // C -> B (XYZ Scaling)
            1.010516, 0.000000, 0.000000,
            0.000000, 1.000000, 0.000000,
            0.000000, 0.000000, 0.721599,

            // C -> C
            1.0, 0.0, 0.0,
            0.0, 1.0, 0.0,
            0.0, 0.0, 1.0,

            1.0, 0.0, 0.0,
            0.0, 1.0, 0.0,
            0.0, 0.0, 1.0,

            1.0, 0.0, 0.0,
            0.0, 1.0, 0.0,
            0.0, 0.0, 1.0,

            // C -> D50 (Bradford)
            1.037765, 0.017182, -0.011978,
            0.015460, 1.005438, 0.020371,
            -0.058148, -0.018868, 0.691416,

            // C -> D50 (Von Kries)
            1.013279, 0.005031, 0.000000,
            0.045808, 0.996264, 0.000000,
            -0.063514, -0.001014, 0.698718,

            // C -> D50 (XYZ Scaling)
            0.983487, 0.000000, 0.000000,
            0.000000, 1.000000, 0.000000,
            0.000000, 0.000000, 0.698721,

            // C -> D55 (Bradford)
            1.018382, 0.004560, -0.008957,
            0.005982, 1.010689, 0.015570,
            -0.040789, -0.012837, 0.773954,

            // C -> D55 (Von Kries)
            1.006768, 0.002564, 0.000000,
            0.023348, 0.998095, 0.000000,
            -0.045848, -0.000516, 0.779698,

            // C -> D55 (XYZ Scaling)
            0.975347, 0.000000, 0.000000,
            0.000000, 1.000000, 0.000000,
            0.000000, 0.000000, 0.779701,

            // C -> D65 (Bradford)
            0.990490, -0.012269, -0.003515,
            -0.007115, 1.015427, 0.006679,
            -0.011434, -0.002878, 0.919313,

            // C -> D65 (Von Kries)
            0.997291, -0.001026, 0.000000,
            -0.009340, 1.000760, 0.000000,
            -0.015193, 0.000208, 0.922047,

            // C -> D65 (XYZ Scaling)
            0.969459, 0.000000, 0.000000,
            0.000000, 1.000000, 0.000000,
            0.000000, 0.000000, 0.922050,

            // C -> D75 (Bradford)
            0.970531, -0.023599,  0.000967,
            -0.016198, 1.017309, -0.000743,
            0.011914,  0.004934,  1.037548,

            // C -> D75 (Von Kries)
            0.990453, -0.003617, 0.000000,
            -0.032927, 1.002683, 0.000000,
            0.009543, 0.000730, 1.037718,

            // C -> D75 (XYZ Scaling)
            0.968360, 0.000000, 0.000000,
            0.000000, 1.000000, 0.000000,
            0.000000, 0.000000, 1.037721,

            // C -> E (Bradford)
            1.040046, 0.026802, -0.005645,
            0.019876, 0.987617, 0.008842,
            -0.033485, -0.011765, 0.843919,

            // C -> E (Von Kries)
            1.013396, 0.005075, 0.000000,
            0.046208, 0.996233, 0.000000,
            -0.033655, -0.001024, 0.846716,

            // C -> E (XYZ Scaling)
            1.019981, 0.000000, 0.000000,
            0.000000, 1.000000, 0.000000,
            0.000000, 0.000000, 0.846719,

            // D50 ->   A (Bradford)
            1.157264,   0.119830, -0.020050,
            0.087174,   0.922061,  0.030403,
            -0.126938, -0.045569,  0.417348,

            // D50 -> A (Von Kries)
            1.052976, 0.020503, 0.000000,
            0.186659, 0.983644, 0.000000,
            -0.125633, -0.004137, 0.430762,

            // D50 -> A (XYZ Scaling)
            1.139034, 0.000000, 0.000000,
            0.000000, 1.000000, 0.000000,
            0.000000, 0.000000, 0.430763,

            // D50 -> B (Bradford)
            1.015344, 0.014785, 0.001735,
            0.009388, 0.985677, -0.003652,
            0.002809, 0.000081, 1.035142,

            // D50 -> B (Von Kries)
            1.004871, 0.001885, 0.000000,
            0.017164, 0.998496, 0.000000,
            0.005627, -0.000381, 1.032740,

            // D50 -> B (XYZ Scaling)
            1.027483, 0.000000, 0.000000,
            0.000000, 1.000000, 0.000000,
            0.000000, 0.000000, 1.032743,

            // D50 -> C (Bradford)
            0.964813, -0.016165,  0.017191,
            -0.016469,  0.994317, -0.029580,
            0.080692,  0.025774,  1.446947,

            // D50 -> C (Von Kries)
            0.987122, -0.004985, 0.000000,
            -0.045378, 1.003977, 0.000000,
            0.089662, 0.001004, 1.431183,

            // D50 -> C (XYZ Scaling)
            1.016791, 0.000000, 0.000000,
            0.000000, 1.000000, 0.000000,
            0.000000, 0.000000, 1.431187,

            // D50 -> D50
            1.0, 0.0, 0.0,
            0.0, 1.0, 0.0,
            0.0, 0.0, 1.0,

            1.0, 0.0, 0.0,
            0.0, 1.0, 0.0,
            0.0, 0.0, 1.0,

            1.0, 0.0, 0.0,
            0.0, 1.0, 0.0,
            0.0, 0.0, 1.0,

            // D50 -> D55 (Bradford)
            0.981751, -0.012159, 0.004411,
            -0.009617, 1.005251, -0.007265,
            0.023309, 0.007844, 1.119548,

            // D50 -> D55 (Von Kries)
            0.993685, -0.002444,  0.000000,
            -0.022249, 1.001949,  0.000000,
            0.024676,  0.000493,  1.115894,

            // D50 -> D55 (XYZ Scaling)
            0.991724, 0.000000, 0.000000,
            0.000000, 1.000000, 0.000000,
            0.000000, 0.000000, 1.115898,

            // D50 -> D65 (Bradford)
            0.955556, -0.028302, 0.012305,
            -0.023049, 1.009944, -0.020494,
            0.063197, 0.021018, 1.330084,

            // D50 -> D65 (Von Kries)
            0.984494, -0.006002, 0.000000,
        -0.054637, 1.004788, 0.000000,
            0.067667, 0.001210, 1.319622,

            // D50 -> D65 (XYZ Scaling)
            0.985737, 0.000000, 0.000000,
            0.000000, 1.000000, 0.000000,
            0.000000, 0.000000, 1.319627,

            // D50 -> D75 (Bradford)
            0.936847, -0.039129, 0.018781,
            -0.032442, 1.011771, -0.031445,
            0.095135, 0.031456, 1.501335,

            // D50 -> D75 (Von Kries)
            0.977862, -0.008569, 0.000000,
            -0.078007, 1.006836, 0.000000,
            0.102432, 0.001727, 1.485168,

            // D50 -> D75 (XYZ Scaling)
            0.984620, 0.000000, 0.000000,
            0.000000, 1.000000, 0.000000,
            0.000000, 0.000000, 1.485174,

            // D50 -> E (Bradford)
            1.002553, 0.009691, 0.008918,
            0.003624, 0.981912, -0.016079,
            0.035984, 0.010595, 1.220878,

            // D50 -> E (Von Kries)
            1.000115, 0.000044, 0.000000,
            0.000401, 0.999965, 0.000000,
            0.042744, -0.000010, 1.211809,

            // D50 -> E (XYZ Scaling)
            1.037108, 0.000000, 0.000000,
            0.000000, 1.000000, 0.000000,
            0.000000, 0.000000, 1.211813,

            // D55 -> A (Bradford)
            1.180601, 0.133653, -0.021693,
            0.097012, 0.918163, 0.032732,
            -0.138643, -0.049919, 0.373005,

            // D55 -> A (Von Kries)
            1.060184, 0.023049, 0.000000,
            0.209842, 0.982241, 0.000000,
            -0.136121, -0.004650, 0.386023,

            // D55 -> A (XYZ Scaling)
            1.148540, 0.000000, 0.000000,
            0.000000, 1.000000, 0.000000,
            0.000000, 0.000000, 0.386024,

            // D55 -> B (Bradford)
            1.034540, 0.027239, -0.002349,
            0.019098, 0.980736, 0.003026,
            -0.019163, -0.007366, 0.924635,

            // D55 -> B (Von Kries)
            1.011356, 0.004348, 0.000000,
            0.039593, 0.996649, 0.000000,
            -0.017339, -0.000878, 0.925479,

            // D55 -> B (XYZ Scaling)
            1.036058, 0.000000, 0.000000,
            0.000000, 1.000000, 0.000000,
            0.000000, 0.000000, 0.925482,

            // D55 -> C (Bradford)
            0.982433, -0.004287,  0.011457,
            -0.006610, 0.989199, -0.019977,
            0.051668,  0.016181,  1.292341,

            // D55 -> C (Von Kries)
            0.993339, -0.002552, 0.000000,
            -0.023228, 1.001966, 0.000000,
            0.058394, 0.000514, 1.282539,

            // D55 -> C (XYZ Scaling)
            1.025276, 0.000000, 0.000000,
            0.000000, 1.000000, 0.000000,
            0.000000, 0.000000, 1.282543,

            // D55 -> D50 (Bradford)
            1.018803, 0.012353, -0.003934,
            0.009594, 0.994842, 0.006418,
            -0.021278, -0.007227, 0.893255,

            // D55 -> D50 (Von Kries)
            1.006412, 0.002455, 0.000000,
            0.022357, 0.998107, 0.000000,
            -0.022266, -0.000495, 0.896136,

            // D55 -> D50 (XYZ Scaling)
            1.008345, 0.000000, 0.000000,
            0.000000, 1.000000, 0.000000,
            0.000000, 0.000000, 0.896140,

            // D55 -> D55
            1.0, 0.0, 0.0,
            0.0, 1.0, 0.0,
            0.0, 0.0, 1.0,

            1.0, 0.0, 0.0,
            0.0, 1.0, 0.0,
            0.0, 0.0, 1.0,

            1.0, 0.0, 0.0,
            0.0, 1.0, 0.0,
            0.0, 0.0, 1.0,

            // D55 -> D65 (Bradford)
            0.972990, -0.016440, 0.007051,
            -0.013357, 1.004598, -0.011734,
            0.036285, 0.012078, 1.187991,

            // D55 -> D65 (Von Kries)
            0.990671, -0.003573, 0.000000,
            -0.032527, 1.002753, 0.000000,
            0.038746, 0.000720, 1.182565,

            // D55 -> D65 (XYZ Scaling)
            0.993963, 0.000000, 0.000000,
            0.000000, 1.000000, 0.000000,
            0.000000, 0.000000, 1.182570,

            // D55 -> D75 (Bradford)
            0.953688, -0.027490, 0.012840,
            -0.022677, 1.006379, -0.021468,
            0.065280, 0.021618, 1.340903,

            // D55 -> D75 (Von Kries)
            0.983939, -0.006152, 0.000000,
            -0.056002, 1.004740, 0.000000,
            0.070060, 0.001240, 1.330918,

            // D55 -> D75 (XYZ Scaling)
            0.992836, 0.000000, 0.000000,
            0.000000, 1.000000, 0.000000,
            0.000000, 0.000000, 1.330923,

            // D55 -> E (Bradford)
            1.021308, 0.021962,  0.004085,
            0.013455, 0.977009, -0.008075,
            0.010784, 0.002161,  1.090481,

            // D55 -> E (Von Kries)
            1.006527, 0.002499, 0.000000,
            0.022756, 0.998075, 0.000000,
            0.016037, -0.000505, 1.085950,

            // D55 -> E (XYZ Scaling)
            1.045763, 0.000000, 0.000000,
            0.000000, 1.000000, 0.000000,
            0.000000, 0.000000, 1.085953,

            // D65 -> A (Bradford)
            1.216371, 0.153235, -0.023966,
            0.110931, 0.915343, 0.035935,
            -0.154983, -0.056006, 0.314346,

            // D65 -> A (Von kries)
            1.071049, 0.026803, 0.000000,
            0.244014, 0.980413, 0.000000,
            -0.150348, -0.005408, 0.326427,

            // D65 -> A (XYZ Scaling)
            1.155516, 0.000000, 0.000000,
            0.000000, 1.000000, 0.000000,
            0.000000, 0.000000, 0.326428,

            // D65 -> B (Bradford)
            1.064164, 0.044624, -0.007852,
            0.032589, 0.976635, 0.012001,
            -0.048965, -0.017493, 0.778436,

            // D65 -> B (Von Kries)
            1.021142, 0.007975, 0.000000,
            0.072613, 0.994171, 0.000000,
            -0.048164, -0.001609, 0.782600,

            // D65 -> B (XYZ Scaling)
            1.042351, 0.000000, 0.000000,
            0.000000, 1.000000, 0.000000,
            0.000000, 0.000000, 0.782603,

            // D65 -> C (Bradford)
            1.009732, 0.012211, 0.003772,
            0.006993, 0.984871, -0.007129,
            0.012581, 0.003235, 1.087795,

            // D65 -> C (Von Kries)
            1.002728, 0.001028, 0.000000,
            0.009367, 0.999248, 0.000000,
            0.016519, -0.000208, 1.084536,

            // D65 -> C (XYZ Scaling)
            1.031503, 0.000000, 0.000000,
            0.000000, 1.000000, 0.000000,
            0.000000, 0.000000, 1.084540,

            // D65 -> D50 (Bradford)
            1.047835, 0.029556, -0.009238,
            0.022897, 0.990481, 0.015050,
            -0.050147, -0.017056, 0.752034,

            // D65 -> D50 (Von Kries)
            1.016089, 0.006069, 0.000000,
            0.055260, 0.995564, 0.000000,
            -0.052154, -0.001224, 0.757788,

            // D65 -> D50 (XYZ Scaling)
            1.014470, 0.000000, 0.000000,
            0.000000, 1.000000, 0.000000,
            0.000000, 0.000000, 0.757790,

            // D65 -> D55 (Bradford)
            1.028213, 0.016898, -0.005936,
            0.013304, 0.995522, 0.009754,
            -0.031540, -0.010637, 0.841840,

            // D65 -> D55 (Von Kries)
            1.009537, 0.003597, 0.000000,
            0.032756, 0.997370, 0.000000,
            -0.033098, -0.000726, 0.845614,

            // D65 -> D55 (XYZ Scaling)
            1.006074, 0.000000, 0.000000,
            0.000000, 1.000000, 0.000000,
            0.000000, 0.000000, 0.845616,

            // D65 -> D65
            1.0, 0.0, 0.0,
            0.0, 1.0, 0.0,
            0.0, 0.0, 1.0,

            1.0, 0.0, 0.0,
            0.0, 1.0, 0.0,
            0.0, 0.0, 1.0,

            1.0, 0.0, 0.0,
            0.0, 1.0, 0.0,
            0.0, 0.0, 1.0,

            // D65 -> D75 (Bradford)
            0.979823, -0.011388,  0.004880,
            -0.009251, 1.001719, -0.008121,
            0.025117,  0.008361,  1.128649,

            // D65 -> D75 (Von Kries)
            0.993120, -0.002596, 0.000000,
            -0.023629, 1.001897, 0.000000,
            0.026719, 0.000523, 1.125446,

            // D65 -> D75 (XYZ Scaling)
            0.998867, 0.000000, 0.000000,
            0.000000, 1.000000, 0.000000,
            0.000000, 0.000000, 1.125450,

            // D65 -> E (Bradford)
            1.050285, 0.039078, -0.002409,
            0.027087, 0.972947, 0.002652,
            -0.023276, -0.009266, 0.917968,

            // D65 -> E (Von kries)
            1.016207, 0.006113, 0.000000,
            0.055662, 0.995532, 0.000000,
            -0.019769, -0.001234, 0.918297,

            // D65 -> E (XYZ Scaling)
            1.052114, 0.000000, 0.000000,
            0.000000, 1.000000, 0.000000,
            0.000000, 0.000000, 0.918300,

            // D75 -> A (Bradford)
            1.243649, 0.167322, -0.025407,
            0.120882, 0.914830, 0.037899,
            -0.165889, -0.060122, 0.278800,

            // D75 -> A (Von Kries)
            1.079173, 0.029548, 0.000000,
            0.269008, 0.979254, 0.000000,
            -0.159335, -0.005962, 0.290041,

            // D75 -> A (XYZ Scaling)
            1.156827, 0.000000, 0.000000,
            0.000000, 1.000000, 0.000000,
            0.000000, 0.000000, 0.290042,

            // D75 -> B (Bradford)
            1.086904, 0.056997, -0.011247,
            0.042021, 0.975291, 0.017469,
            -0.067883, -0.023992, 0.689828,

            // D75 -> B (Von Kries)
            1.028470, 0.010625, 0.000000,
            0.096735, 0.992539, 0.000000,
            -0.067258, -0.002144, 0.695366,

            // D75 -> B (XYZ Scaling)
            1.043533, 0.000000, 0.000000,
            0.000000, 1.000000, 0.000000,
            0.000000, 0.000000, 0.695369,

            // D75 -> C (Bradford)
            1.030774,   0.023916, -0.000943,
            0.016405,   0.983362,  0.000688,
            -0.011913, -0.004951,  0.963819,

            // D75 -> C (Von Kries)
            1.009762, 0.003643, 0.000000,
            0.033168, 0.997442, 0.000000,
            -0.009311, -0.000735,  0.963647,

            // D75 -> C (XYZ Scaling)
            1.032673, 0.000000, 0.000000,
            0.000000, 1.000000, 0.000000,
            0.000000, 0.000000, 0.963650,

            // D75 -> D50 (Bradford)
            1.070127, 0.041775, -0.012512,
            0.032186, 0.988978, 0.020311,
            -0.068484, -0.023368, 0.666442,

            // D75 -> D50 (Von Kries)
            1.023337, 0.008709, 0.000000,
            0.079295, 0.993884, 0.000000,
            -0.070673, -0.001757, 0.673320,

            // D75 -> D50 (XYZ Scaling)
            1.015620, 0.000000, 0.000000,
            0.000000, 1.000000, 0.000000,
            0.000000, 0.000000, 0.673322,

            // D75 -> D55 (Bradford)
            1.049904, 0.028885, -0.009591,
            0.022560, 0.993940, 0.015697,
            -0.051476, -0.017431, 0.745981,

            // D75 -> D55 (Von Kries)
            1.016680, 0.006225, 0.000000,
            0.056676, 0.995628, 0.000000,
            -0.053572, -0.001255, 0.751356,

            // D75 -> D55 (XYZ Scaling)
            1.007215, 0.000000, 0.000000,
            0.000000, 1.000000, 0.000000,
            0.000000, 0.000000, 0.751359,

            // D75 -> D65 (Bradford)
            1.020813, 0.011641, -0.004330,
            0.009243, 0.998329, 0.007144,
            -0.022785, -0.007655, 0.886059,

            // D75 -> D65 (Von Kries)
            1.006992, 0.002609, 0.000000,
            0.023758, 0.998167, 0.000000,
            -0.023919, -0.000526,  0.888531,

            // D75 -> D65 (XYZ Scaling)
            1.001134, 0.000000, 0.000000,
            0.000000, 1.000000, 0.000000,
            0.000000, 0.000000, 0.888534,

            // D75 -> D75
            1.0, 0.0, 0.0,
            0.0, 1.0, 0.0,
            0.0, 0.0, 1.0,

            1.0, 0.0, 0.0,
            0.0, 1.0, 0.0,
            0.0, 0.0, 1.0,

            1.0, 0.0, 0.0,
            0.0, 1.0, 0.0,
            0.0, 0.0, 1.0,

            // D75 -> E (Bradford)
            1.072560, 0.051258, -0.006403,
            0.036583, 0.971617, 0.009183,
            -0.044763, -0.016548, 0.813408,

            // D75 -> E (Von Kries)
            1.023456, 0.008754, 0.000000,
            0.079698, 0.993854, 0.000000,
        -0.041900, -0.001766, 0.815937,

            // D75 -> E (XYZ Scaling)
            1.053308, 0.000000, 0.000000,
            0.000000, 1.000000, 0.000000,
            0.000000, 0.000000, 0.815940,

            // E ->     A (Bradford)
            1.154755, 0.110892, -0.023397,
            0.082246, 0.937839, 0.036653,
            -0.138722, -0.048732, 0.342214,

            // E -> A (Von Kries)
            1.052848, 0.020457, 0.000000,
            0.186247, 0.983669, 0.000000,
            -0.140810, -0.004127, 0.355469,

            // E -> A (XYZ Scaling)
            1.098280, 0.000000, 0.000000,
            0.000000, 1.000000, 0.000000,
            0.000000, 0.000000, 0.355470,

            // E -> B (Bradford)
            1.012951, 0.005123, -0.005910,
            0.005370, 1.003671, 0.010188,
            -0.027601, -0.008795, 0.847953,

            // E -> B (Von Kries)
            1.004757, 0.001841, 0.000000,
            0.016766, 0.998529, 0.000000,
            -0.030798, -0.000371, 0.852227,

            // E -> B (XYZ Scaling)
            0.990720, 0.000000, 0.000000,
            0.000000, 1.000000, 0.000000,
            0.000000, 0.000000, 0.852230,

            // E -> C (Bradford)
            0.962209, -0.026032, 0.006709,
            -0.019703, 1.012944, -0.010744,
            0.037905, 0.013088, 1.185066,

            // E -> C (Von Kries)
            0.987012, -0.005028, 0.000000,
            -0.045772, 1.004013, 0.000000,
            0.039174, 0.001014, 1.181026,

            // E -> C (XYZ Scaling)
            0.980410, 0.000000, 0.000000,
            0.000000, 1.000000, 0.000000,
            0.000000, 0.000000, 1.181030,

            // E -> D50 (Bradford)
            0.997754, -0.009768, -0.007417,
            -0.004163, 1.018316, 0.013442,
            -0.029371, -0.008549, 0.819186,

            // E -> D50 (Von Kries)
            0.999887, -0.000044, 0.000000,
            -0.000393, 1.000033, 0.000000,
            -0.035270, 0.000010, 0.825207,

            // E -> D50 (XYZ Scaling)
            0.964220, 0.000000, 0.000000,
            0.000000, 1.000000, 0.000000,
            0.000000, 0.000000, 0.825210,

            // E -> D55 (Bradford)
            0.979467, -0.022009, -0.003832,
            -0.013568, 1.023820, 0.007632,
            -0.009659, -0.001811, 0.917050,

            // E -> D55 (Von Kries)
            0.993574, -0.002488, 0.000000,
            -0.022644, 1.001984, 0.000000,
            -0.014684, 0.000503, 0.920847,

            // E -> D55 (XYZ Scaling)
            0.956240, 0.000000, 0.000000,
            0.000000, 1.000000, 0.000000,
            0.000000, 0.000000, 0.920850,

            // E -> D65 (Bradford)
            0.953167, -0.038259, 0.002612,
            -0.026600, 1.028843, -0.003042,
            0.023901, 0.009415, 1.089399,

            // E -> D65 (Von Kries)
            0.984385, -0.006045, 0.000000,
            -0.055029, 1.004824, 0.000000,
            0.021116, 0.001220, 1.088965,

            // E -> D65 (XYZ Scaling)
            0.950467, 0.000000, 0.000000,
            0.000000, 1.000000, 0.000000,
            0.000000, 0.000000, 1.088969,

            // E -> D75 (Bradford)
            0.934355, -0.049157, 0.007910,
            -0.035658, 1.030889, -0.011919,
            0.050694, 0.018268, 1.229589,

            // E -> D75 (Von Kries)
            0.977754, -0.008612, 0.000000,
            -0.078398, 1.006874, 0.000000,
            0.050039, 0.001738, 1.225576,

            // E -> D75 (XYZ Scaling)
            0.949390, 0.000000, 0.000000,
            0.000000, 1.000000, 0.000000,
            0.000000, 0.000000, 1.225580,

            // E -> E
            1.0, 0.0, 0.0,
            0.0, 1.0, 0.0,
            0.0, 0.0, 1.0,

            1.0, 0.0, 0.0,
            0.0, 1.0, 0.0,
            0.0, 0.0, 1.0,

            1.0, 0.0, 0.0,
            0.0, 1.0, 0.0,
            0.0, 0.0, 1.0

        };

        return CAmatrix[index];
    }

// public methods
public:

    static double gamma(RGBSpaces rgb_space)
    {
        if (rgb_space == ADOBE_RGB)
        {
            return 2.2;
        }
        else if (rgb_space == APPLE_RGB)
        {
            return 1.8;
        }
        else if (rgb_space == BEST_RGB)
        {
            return 2.2;
        }
        else if (rgb_space == BETA_RGB)
        {
            return 2.2;
        }
        else if (rgb_space == BRUCE_RGB)
        {
            return 2.2;
        }
        else if (rgb_space == CIE_RGB)
        {
            return 2.2;
        }
        else if (rgb_space == DON_RGB4)
        {
            return 1.8;
        }
        else if (rgb_space == ECI_RGB)
        {
            return 2.2;
        }
        else if (rgb_space == EKTA_SPACE)
        {
            return 2.2;
        }
        else if (rgb_space == NTSC_RGB)
        {
            return 2.2;
        }
        else if (rgb_space == PAL_RGB)
        {
            return 2.2;
        }
        else if (rgb_space == PROPHOTO)
        {
            return 1.8;
        }
        else if (rgb_space == SMPTE_C)
        {
            return 2.2;
        }
        else if (rgb_space == SRGB)
        {
            return 2.2; // about 2.2
        }
        else if (rgb_space == WIDE_GAMUT)
        {
            return 2.2;
        }
        else
        {
            assert(false);
            return 0.0;
        }
    }

    static Illuminant refIlluminant(RGBSpaces rgb_space)
    {
        // RGB WORKING SPACE DATA
        //
        // Illuminant Reference for each RGB Space.
        //

        if (rgb_space == ADOBE_RGB)
        {
            return VCG_ILLUMINANT_D65;
        }
        else if (rgb_space == APPLE_RGB)
        {
            return VCG_ILLUMINANT_D65;
        }
        else if (rgb_space == BEST_RGB)
        {
            return VCG_ILLUMINANT_D50;
        }
        else if (rgb_space == BETA_RGB)
        {
            return VCG_ILLUMINANT_D50;
        }
        else if (rgb_space == BRUCE_RGB)
        {
            return VCG_ILLUMINANT_D65;
        }
        else if (rgb_space == CIE_RGB)
        {
            return VCG_ILLUMINANT_E;
        }
        else if (rgb_space == DON_RGB4)
        {
            return VCG_ILLUMINANT_D50;
        }
        else if (rgb_space == ECI_RGB)
        {
            return VCG_ILLUMINANT_D50;
        }
        else if (rgb_space == EKTA_SPACE)
        {
            return VCG_ILLUMINANT_D50;
        }
        else if (rgb_space == NTSC_RGB)
        {
            return VCG_ILLUMINANT_C;
        }
        else if (rgb_space == PAL_RGB)
        {
            return VCG_ILLUMINANT_D65;
        }
        else if (rgb_space == PROPHOTO)
        {
            return VCG_ILLUMINANT_D50;
        }
        else if (rgb_space == SMPTE_C)
        {
            return VCG_ILLUMINANT_D65;
        }
        else if (rgb_space == SRGB)
        {
            return VCG_ILLUMINANT_D65;
        }
        else if (rgb_space == WIDE_GAMUT)
        {
            return VCG_ILLUMINANT_D50;
        }
        else
        {
            assert(false);
            return VCG_ILLUMINANT_INVALID;
        }
    }

    static Color4<T> RGBtoHSV(const Color4<T> & color)
    {
        double h,s,v;
        RGBtoHSV(static_cast<double>(color[0]), static_cast<double>(color[1]),
      static_cast<double>(color[2]), h,s,v);
        Color4<T> c(h,s,v,color[3]);
        return c;
    }

    static void RGBtoHSV(double R, double G, double B, double &H, double &S, double &V)
    {
    double v_min = std::min(std::min(R, G), B);  // Min value of RGB
    double v_max = std::max(std::max(R, G), B);  // Max value of RGB

        double delta = v_max - v_min;   //Delta RGB value

        V = v_max;

        if (delta < 0.00000000001)   // This is a gray, no chroma...
        {
            H = 0.0;                   // HSV results = 0 ÷ 1
            S = 0.0;
        }
        else                         // Chromatic data...
        {
            S = delta / v_max;

            double deltaR = (((v_max - R) / 6) + (delta/2.0) ) / delta;
            double deltaG = (((v_max - G) / 6) + (delta/2.0) ) / delta;
            double deltaB = (((v_max - B) / 6) + (delta/2.0) ) / delta;

            if ( R == v_max )
                H = deltaB - deltaG;
            else if (G == v_max)
                H = (1.0 / 3.0) + deltaR - deltaB;
            else if (B == v_max)
                H = (2.0 / 3.0) + deltaG - deltaR;
      else H = 0; // this final branch should never happen...

      if ( H < 0 ) H += 1.0;
      if ( H > 1 ) H -= 1.0;
        }
    }

    static Color4<T> HSVtoRGB(const Color4<T> & color)
    {
        double r,g,b;
        HSVtoRGB(static_cast<double>(color[0]), static_cast<double>(color[1]),
      static_cast<double>(color[2]), r,g,b);
        Color4<T> c(r,g,b,color[3]);
        return c;
    }

    static void HSVtoRGB(double H, double S, double V, double &R, double &G, double &B)
    {
        if (S == 0)
        {
            R = V;
            G = V;
            B = V;
        }
        else
        {
            double var_h = H * 6.0;

            if (var_h == 6.0)
                var_h = 0.0;     // H must be < 1

            int var_i = static_cast<int>(var_h);
            double var_1 = V * (1.0 - S);
            double var_2 = V * (1.0 - S * (var_h - var_i ));
            double var_3 = V * (1.0 - S * (1.0 - (var_h - var_i)));

            double var_r, var_g, var_b;

            if (var_i == 0)
            {
                var_r = V;
                var_g = var_3;
                var_b = var_1;
            }
            else if (var_i == 1)
            {
                var_r = var_2;
                var_g = V;
                var_b = var_1;
            }
            else if (var_i == 2)
            {
                var_r = var_1;
                var_g = V;
                var_b = var_3;
            }
            else if (var_i == 3)
            {
                var_r = var_1;
                var_g = var_2;
                var_b = V;
            }
            else if (var_i == 4)
            {
                var_r = var_3;
                var_g = var_1;
                var_b = V;
            }
            else
            {
                var_r = V;
                var_g = var_1;
                var_b = var_2;
            }

            R = var_r;
            G = var_g;
            B = var_b;
        }

    }

    static Color4<T> XYZtoRGB(const Color4<T> & color, Illuminant src,
        RGBSpaces dest, ConeResponse response = BRADFORD)
    {
        double r,g,b;
        XYZtoRGB(static_cast<double>(color[0]), static_cast<double>(color[1]),
      static_cast<double>(color[2]), src, r,g,b, dest, response);
        Color4<T> c(r,g,b,color[3]);
        return c;
    }

    static void XYZtoRGB(double X, double Y, double Z, Illuminant src,
        double &R, double &G, double &B, RGBSpaces space, ConeResponse response = BRADFORD)
    {
        double Xp, Yp, Zp;
        chromaticAdaptation(X, Y, Z, src, Xp, Yp, Zp, refIlluminant(space), response);

        int index = static_cast<int>(space) * 3 * 3;
        double r = Xp * XYZ2RGB(index)   + Yp * XYZ2RGB(index+3) + Zp * XYZ2RGB(index+6);
        double g = Xp * XYZ2RGB(index+1) + Yp * XYZ2RGB(index+4) + Zp * XYZ2RGB(index+7);
        double b = Xp * XYZ2RGB(index+2) + Yp * XYZ2RGB(index+5) + Zp * XYZ2RGB(index+8);

        // Account for gamma correction
        if (space == SRGB)
        {
            if (r > 0.0031308)
                R = 1.055 * pow(r, 1.0/2.4) - 0.055;
            else
                R = 12.92 * r;

            if (g > 0.0031308)
                G = 1.055 * pow(g, 1.0/2.4) - 0.055;
            else
                G = 12.92 * g;

            if (b > 0.0031308)
                B = 1.055 * pow(b, 1.0/2.4) - 0.055;
            else
                B = 12.92 * b;
        }
        else
        {
            double lambda = gamma(space);
            R = pow(r, 1.0/lambda);
            G = pow(g, 1.0/lambda);
            B = pow(b, 1.0/lambda);
        }
    }

    static Color4<T> RGBtoXYZ(const Color4<T> & color, RGBSpaces space,
        Illuminant dest, ConeResponse response = BRADFORD)
    {
        double x,y,z;
        RGBtoXYZ(static_cast<double>(color[0]), static_cast<double>(color[1]),
            static_cast<double>(color[2]), space, x,y,z, dest, response);
        Color4<T> c(x,y,z,color[3]);
        return c;
    }

    static void RGBtoXYZ(double R, double G, double B, RGBSpaces space,
        double &X, double &Y, double &Z, Illuminant dest, ConeResponse response = BRADFORD)
    {
        // Account for Gamma Correction
        double r,g,b;
        if (space == SRGB)
        {
            if (R <= 0.04045)
                r = R / 12.92;
            else
                r = pow((R + 0.055) / 1.055, 2.4);

            if (G <= 0.04045)
                g = G / 12.92;
            else
                g = pow((G + 0.055) / 1.055, 2.4);

            if (B <= 0.04045)
                b = B / 12.92;
            else
                b = pow((B + 0.055) / 1.055, 2.4);
        }
        else
        {
            double lambda = gamma(space);
            r = pow(R, lambda);
            g = pow(G, lambda);
            b = pow(B, lambda);
        }

        int index = static_cast<int>(space) * 3 * 3;
        double Xt = r * RGB2XYZ(index) + g * RGB2XYZ(index+3) + b * RGB2XYZ(index+6);
        double Yt = r * RGB2XYZ(index+1) + g * RGB2XYZ(index+4) + b * RGB2XYZ(index+7);
        double Zt = r * RGB2XYZ(index+2) + g * RGB2XYZ(index+5) + b * RGB2XYZ(index+8);

        // Convert from reference illuminant to the desired one
        chromaticAdaptation(Xt, Yt, Zt, refIlluminant(space), X, Y, Z, dest, response);
    }

    static Color4<T> XYZtoCIELab(const Color4<T> & color, Illuminant ref)
    {
        double L,a,b;
        XYZtoCIELab(static_cast<double>(color[0]), static_cast<double>(color[1]),
            static_cast<double>(color[2]), L,a,b, ref);
        Color4<T> c(L,a,b,color[3]);
        return c;
    }

    static void XYZtoCIELab(double X, double Y, double Z, double &L, double &a, double &b,
        Illuminant whiteRef)
    {
        // Reference white computation
        // Note: The reference white depends only on the illuminant
        //       (it is independent on the RGB Working Space)
        double Xr, Yr, Zr;
        RGBtoXYZ(1.0, 1.0, 1.0, SRGB, Xr, Yr, Zr, whiteRef);

        double xr = X / Xr;
        double yr = Y / Yr;
        double zr = Z / Zr;

        double cieEpsilon = CIE_EPSILON();
        double cieKi = CIE_KI();

        double fx;
        if (xr > cieEpsilon)
            fx = pow(xr, 1.0/3.0);
        else
            fx = (cieKi * xr + 16.0) / 116.0;

        double fy;
        if (yr > cieEpsilon)
            fy = pow(yr, 1.0/3.0);
        else
            fy = (cieKi * yr + 16.0) / 116.0;

        double fz;
        if (zr > cieEpsilon)
            fz = pow(zr, 1.0/3.0);
        else fz = (cieKi * zr + 16.0) / 116.0;

        L = 116.0 * fy - 16.0;
        a = 500.0 * (fx - fy);
        b = 200.0 * (fy - fz);
    }

    static Color4<T> CIELabtoXYZ(const Color4<T> & color, Illuminant ref)
    {
        double x,y,z;
        CIELabtoXYZ(static_cast<double>(color[0]), static_cast<double>(color[1]),
            static_cast<double>(color[2]), x,y,z, ref);
        Color4<T> c(x,y,z,color[3]);
        return c;
    }

    static void CIELabtoXYZ(double L, double a, double b, double &X, double &Y, double &Z,
        Illuminant whiteRef)
    {
        double cieEpsilon = CIE_EPSILON();
        double cieKi = CIE_KI();

        double value;

        double yr;
        if (L > cieKi * cieEpsilon)
        {
            value = (L + 16.0) / 116.0;
            yr = value * value * value;
        }
        else
            yr = L / cieKi;

        double fy;
        if (yr > cieEpsilon)
            fy = (L + 16.0) / 116.0;
        else
            fy = (cieKi * yr + 16.0) / 116.0;

        double fz = fy - (b / 200.0);
        double fz_cubed = fz * fz * fz;

        double fx = (a / 500.0) + fy;
        double fx_cubed = fx * fx * fx;

        double xr;
        if (fx_cubed > cieEpsilon)
            xr = fx_cubed;
        else
            xr = (116.0 * fx - 16.0) / cieKi;

        double zr;
        if (fz_cubed > cieEpsilon)
            zr = fz_cubed;
        else
            zr = (116.0 * fz - 16.0) / cieKi;

        // Reference white computation
        // Note: The reference white depends only on the illuminant
        //       (it is independent on the RGB Working Space)
        double Xr, Yr, Zr;
        RGBtoXYZ(1.0, 1.0, 1.0, SRGB, Xr, Yr, Zr, whiteRef);

        X = xr * Xr;
        Y = yr * Yr;
        Z = zr * Zr;
    }

    // RGB --> HSL
    static Color4<T> RGBtoHSL(const Color4<T> & color)
    {
        double h,s,l;
        RGBtoHSL(static_cast<double>(color[0]), static_cast<double>(color[1]),
            static_cast<double>(color[2]), h,s,l);
        Color4<T> c(h,s,l,color[3]);
        return c;
    }

    // RGB --> HSL
    static void RGBtoHSL(double R, double G, double B, double &H, double &S, double &L)
    {
        double v = std::min(R,G);
        double v_min = std::min(v, B);    // Min value of RGB

        v = std::max(R,G);
        double v_max = std::max(v, B);    // Max value of RGB

        double delta = v_max - v_min;         // Delta RGB value

        L = (v_max + v_min) / 2.0;

        if (delta == 0.0)                     // This is a gray, no chroma...
        {
            H = 0.0;
            S = 0.0;
        }
        else                                  // Chromatic data...
        {
            if ( L < 0.5 )
                S = delta / (v_max + v_min);
            else
                S = delta / (2.0 - v_max - v_min);

            double deltaR = (((v_max - R) / 6.0) + (delta/2.0)) / delta;
            double deltaG = (((v_max - G) / 6.0) + (delta/2.0)) / delta;
            double deltaB = (((v_max - B) / 6.0) + (delta/2.0)) / delta;

            if (R == v_max)
                H = deltaB - deltaG;
            else if (G == v_max)
                H = (1.0 / 3.0) + deltaR - deltaB;
            else if (B == v_max)
                H = (2.0 / 3.0) + deltaG - deltaR;

            if ( H < 0.0 )
                H += 1.0;

            if ( H > 1.0 )
                H -= 1.0;
        }
    }

    static Color4<T> HSLtoRGB(const Color4<T> & color)
    {
        double r,g,b;
        HSLtoRGB(static_cast<double>(color[0]), static_cast<double>(color[1]),
            static_cast<double>(color[2]), r,g,b);
        Color4<T> c(r,g,b,color[3]);
        return c;
    }

    // HSL --> RGB
    static void HSLtoRGB(double H, double S, double L, double &R, double &G, double &B)
    {
        if (S == 0.0)
        {
            R = L;
            G = L;
            B = L;
        }
        else
        {
            double var_1, var_2;

            if (L < 0.5)
                var_2 = L * ( 1 + S );
            else
                var_2 = ( L + S ) - ( S * L );

            var_1 = 2 * L - var_2;

            R = Hue2RGB(var_1, var_2, H + (1.0/3.0));
            G = Hue2RGB(var_1, var_2, H );
            B = Hue2RGB(var_1, var_2, H - (1.0/3.0));
        }

    }

    static double Hue2RGB(double v1, double v2, double vH)
    {
        if ( vH < 0 )
            vH += 1.0;

        if ( vH > 1 )
            vH -= 1.0;

        if ( (6.0 * vH) < 1.0)
            return (v1 + ( v2 - v1 ) * 6.0 * vH);

        if ( (2.0 * vH) < 1.0)
            return v2;

        if ( (3.0 * vH) < 2.0)
            return ( v1 + ( v2 - v1 ) * ((2.0/3.0) - vH) * 6.0);

        return v1;
    }

    static Color4<T> xyYtoXYZ(const Color4<T> & color)
    {
        double X,Y,Z;
        xyYtoXYZ(static_cast<double>(color[0]), static_cast<double>(color[1]),
            static_cast<double>(color[2]), X,Y,Z);

        Color4<T> c(X,Y,Z,color[3]);
        return c;
    }

    // CIE xyY --> CIE XYZ
    static void xyYtoXYZ(double x, double y, double _Y, double &X, double &Y, double &Z)
    {
        X = x * (Y / y);
        Y = _Y;
        Z = (1.0 - x - y) * (Y / y);
    }

    static Color4<T> XYZtoxyY(const Color4<T> & color)
    {
        double x,y,Y;
        XYZtoxyY(static_cast<double>(color[0]), static_cast<double>(color[1]),
            static_cast<double>(color[2]), x, y, Y);

        Color4<T> c(x,y,Y,color[3]);
        return c;
    }

    // CIE XYZ --> CIE xyY
    static void XYZtoxyY(double X, double _Y, double Z, double &x, double &y, double &Y)
    {
        x = X / (X + Y + Z);
        y = Y / (X + Y + Z);
        Y = _Y;
    }

    // XYZ (Illuminant src) --> XYZ (Illuminant dest) - [ILLUMINANT CHANGE]
    static Color4<T> chromaticAdaptation(const Color4<T> & color, Illuminant src,
        Illuminant dst, ConeResponse response = BRADFORD)
    {
        double X,Y,Z;
    chromaticAdaptation(static_cast<double>(color[0]), static_cast<double>(color[1]),
            static_cast<double>(color[2]), src, X, Y, Z, dst, response);

        Color4<T> c(X,Y,Z,color[3]);
        return c;
    }

    // XYZ (Illuminant src) --> XYZ (Illuminant dest) - [ILLUMINANT CHANGE]
    static void chromaticAdaptation(double Xi, double Yi, double Zi, Illuminant src,
        double &X, double &Y, double &Z, Illuminant dst, ConeResponse response = BRADFORD)
    {
        int index = static_cast<int>(src) * 8 * 3 * 3 * 3 + static_cast<int>(dst) * 3 * 3 * 3 +
            static_cast<int>(response) * 3 * 3;

        X = CA(index)   * Xi + CA(index+3) * Yi + CA(index+6) * Zi;
        Y = CA(index+1) * Xi + CA(index+4) * Yi + CA(index+7) * Zi;
        Z = CA(index+2) * Xi + CA(index+5) * Yi + CA(index+8) * Zi;
    }

    // RGB (working space src) --> RGB (working space dest) - [RGB WORKING SPACE CHANGE]
    static Color4<T> RGBtoRGB(const Color4<T> & color, RGBSpaces rgbsrc, RGBSpaces rgbdest,
        ConeResponse response = BRADFORD)
    {
        double R,G,B;
        RGBtoRGB(static_cast<double>(color[0]), static_cast<double>(color[1]),
            static_cast<double>(color[2]), rgbsrc, R,G,B, rgbdest, response);

        Color4<T> c(R,G,B,color[3]);
        return c;
    }

    // RGB (working space src) --> RGB (working space dest) - [RGB WORKING SPACE CHANGE]
    static void RGBtoRGB(double Ri, double Gi, double Bi, RGBSpaces rgbsrc,
        double &R, double &G, double &B, RGBSpaces rgbdest, ConeResponse response = BRADFORD)
    {
        double X,Y,Z;
        RGBtoXYZ(Ri, Gi, Bi, rgbsrc, X,Y,Z, refIlluminant(rgbsrc), response);
        XYZtoRGB(X,Y,Z, refIlluminant(rgbsrc), R,G,B, rgbdest, response);
    }

};


} // end of NameSpace VCG

#endif /*  __VCGLIB_COLORSPACE */