00001 /*************************************************************************** 00002 * Copyright (C) 1998-2009 by authors (see AUTHORS.txt ) * 00003 * * 00004 * This file is part of LuxRender. * 00005 * * 00006 * Lux Renderer is free software; you can redistribute it and/or modify * 00007 * it under the terms of the GNU General Public License as published by * 00008 * the Free Software Foundation; either version 3 of the License, or * 00009 * (at your option) any later version. * 00010 * * 00011 * Lux Renderer is distributed in the hope that it will be useful, * 00012 * but WITHOUT ANY WARRANTY; without even the implied warranty of * 00013 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * 00014 * GNU General Public License for more details. * 00015 * * 00016 * You should have received a copy of the GNU General Public License * 00017 * along with this program. If not, see <http://www.gnu.org/licenses/>. * 00018 * * 00019 * This project is based on PBRT ; see http://www.pbrt.org * 00020 * Lux Renderer website : http://www.luxrender.net * 00021 ***************************************************************************/ 00022 00023 // contrast.cpp* 00024 #include "contrast.h" 00025 #include "dynload.h" 00026 00027 using namespace lux; 00028 00029 // ContrastOp Method Definitions 00030 void ContrastOp::Map(vector<XYZColor> &xyz, int xRes, int yRes, 00031 float maxDisplayY) const { 00032 // Compute world adaptation luminance, _Ywa_ 00033 float Ywa = 0.; 00034 for (int i = 0; i < xRes * yRes; ++i) { 00035 if (xyz[i].Y() > 0) 00036 Ywa += logf(xyz[i].Y()); 00037 } 00038 00039 Ywa = expf(Ywa / (xRes * yRes)); 00040 // Compute contrast-preserving scalefactor, _s_ 00041 float s = powf((1.219f + powf(displayAdaptationY, 0.4f)) / 00042 (1.219f + powf(Ywa, 0.4f)), 2.5f) / maxDisplayY; 00043 for (int i = 0; i < xRes*yRes; ++i) 00044 xyz[i] *= s; 00045 } 00046 ToneMap * ContrastOp::CreateToneMap(const ParamSet &ps) { 00047 float day = ps.FindOneFloat("ywa", 50.f); 00048 return new ContrastOp(day); 00049 } 00050 00051 static DynamicLoader::RegisterToneMap<ContrastOp> r("contrast");