Files
rawTherapee/rtengine/color.h

105 lines
4.3 KiB
C++

/*
* This file is part of RawTherapee.
*
* Copyright (c) 2004-2010 Gabor Horvath <hgabor@rawtherapee.com>
*
* RawTherapee 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 3 of the License, or
* (at your option) any later version.
*
* RawTherapee 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 for more details.
*
* You should have received a copy of the GNU General Public License
* along with RawTherapee. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef _COLOR_H_
#define _COLOR_H_
#include <math.h>
#include "LUT.h"
#define D50x 0.96422
#define D50z 0.82521
#define u0 4.0*D50x/(D50x+15+3*D50z)
#define v0 9.0/(D50x+15+3*D50z)
namespace rtengine {
class Color {
public:
const static double sRGBGamma; // standard average gamma
const static double sRGBGammaCurve; // 2.4 in the curve
static LUTf cachef;
static LUTf gamma2curve;
// look-up tables for the standard srgb gamma and its inverse (filled by init())
static LUTf igammatab_srgb;
static LUTf gammatab_srgb;
// look-up tables for the simple exponential gamma
static LUTf gammatab;
static void init ();
static void cleanup ();
static void rgb2hsv (float r, float g, float b, float &h, float &s, float &v);
static void rgb2hsv (int r, int g, int b, float &h, float &s, float &v);
static void hsv2rgb (float h, float s, float v, float &r, float &g, float &b);
static void hsv2rgb (float h, float s, float v, int &r, int &g, int &b);
static void xyz2srgb (float x, float y, float z, float &r, float &g, float &b);
static void xyz2rgb (float x, float y, float z, float &r, float &g, float &b, float rgb_xyz[3][3]);
static void Lab2XYZ(float L, float a, float b, float &x, float &y, float &z);
static void XYZ2Lab(float X, float Y, float Z, float &L, float &a, float &b);
static void Lab2Yuv(float L, float a, float b, float &Y, float &u, float &v);
static void Yuv2Lab(float Y, float u, float v, float &L, float &a, float &b, double wp[3][3]);
static void calcGamma (double pwr, double ts, int mode, int imax, double &gamma0, double &gamma1, double &gamma2, double &gamma3, double &gamma4,double &gamma5);
// standard srgb gamma and its inverse
static inline double gamma2 (double x) {
return x <= 0.00304 ? x*12.92 : 1.055*exp(log(x)/sRGBGammaCurve)-0.055;
}
static inline double igamma2 (double x) {
return x <= 0.03928 ? x/12.92 : exp(log((x+0.055)/1.055)*sRGBGammaCurve);
}
// gamma function with adjustable parameters
static inline double gamma (double x, double gamma, double start, double slope, double mul, double add){
return (x <= start ? x*slope : exp(log(x)/gamma)*mul-add);
}
static inline double igamma (double x, double gamma, double start, double slope, double mul, double add){
return (x <= start*slope ? x/slope : exp(log((x+add)/mul)*gamma) );
}
// gamma functions on [0,65535] based on look-up tables
static inline float gamma_srgb (int x) { return gammatab_srgb[x]; }
static inline float gamma (int x) { return gammatab[x]; }
static inline float igamma_srgb (int x) { return igammatab_srgb[x]; }
static inline float gamma_srgb (float x) { return gammatab_srgb[x]; }
static inline float gamma (float x) { return gammatab[x]; }
static inline float igamma_srgb (float x) { return igammatab_srgb[x]; }
//static inline float gamma_srgb (double x) { return gammatab_srgb[x]; }
//static inline float gamma (double x) { return gammatab[x]; }
//static inline float igamma_srgb (double x) { return igammatab_srgb[x]; }
//void gamutmap(LabImage* );
static void gamutmap(float &X, float &Y, float &Z, const double p[3][3]);
static inline float f2xyz(float f) {
const float epsilonExpInv3 = 6.0/29.0;
const float kappaInv = 27.0/24389.0; // inverse of kappa
return (f > epsilonExpInv3) ? f*f*f : (116 * f - 16) * kappaInv;
}
};
}
#endif