geo/tcShadowFreeChromaticities.cpp

   1 /***************************************************************************
   2  *   This file is part of Tecorrec.                                        *
   3  *   Copyright 2008 James Hogan <james@albanarts.com>                      *
   4  *                                                                         *
   5  *   Tecorrec is free software: you can redistribute it and/or modify      *
   6  *   it under the terms of the GNU General Public License as published by  *
   7  *   the Free Software Foundation, either version 2 of the License, or     *
   8  *   (at your option) any later version.                                   *
   9  *                                                                         *
  10  *   Tecorrec is distributed in the hope that it will be useful,           *
  11  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  13  *   GNU General Public License for more details.                          *
  14  *                                                                         *
  15  *   You should have received a copy of the GNU General Public License     *
  16  *   along with Tecorrec.  If not, write to the Free Software Foundation,  *
  17  *   Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.   *
  18  ***************************************************************************/
  19
  20 /**
  21  * @file tcShadowFreeChromaticities.cpp
  22  * @brief Remove the shadows from a set of chromaticities.
  23  */
  24
  25 #include "tcShadowFreeChromaticities.h"
  26 #include "tcChannel.h"
  27
  28 #include <QObject>
  29
  30 #include <cmath>
  31
  32 /*
  33  * Constructors + destructor
  34  */
  35
  36 /// Primary constructor.
  37 tcShadowFreeChromaticities::tcShadowFreeChromaticities(const QList<tcChannel*>& chromaticities)
  38 : tcIlluminantDirection(chromaticities, chromaticities.size(), tr("Shadow free chromaticities"), tr("Re-chromatised illuminant invariant"))
  39 {
  40   for (int i = 0; i < chromaticities.size(); ++i)
  41   {
  42     channels()[i]->setName(tr("sfc(%1)").arg(chromaticities[i]->name()));
  43     channels()[i]->setDescription(tr("Shadow-free chromaticity of %1").arg(chromaticities[i]->name()));
  44   }
  45 }
  46
  47 /// Destructor.
  48 tcShadowFreeChromaticities::~tcShadowFreeChromaticities()
  49 {
  50 }
  51
  52 /*
  53  * Interface for derived class to implement
  54  */
  55
  56 void tcShadowFreeChromaticities::loadPortions(const QList< Reference< tcPixelData<float> > >& chromaticities, int width, int height)
  57 {
  58   QList< Reference< tcPixelData<float> > > newChromaticityData;
  59   for (int i = 0; i < numChromaticities(); ++i)
  60   {
  61     Reference< tcPixelData<GLfloat> > newPixelData = new tcPixelData<GLfloat>(width, height);
  62     newChromaticityData += newPixelData;
  63     m_portions += newPixelData;
  64   }
  65
  66   // Go through the pixels
  67   maths::VarVector<float> logChromaticity(numChromaticities());
  68   maths::VarVector<float> temp(numChromaticities());
  69   for (int i = 0; i < width*height; ++i)
  70   {
  71     // Fill log chromaticity vector
  72     for (int channel = 0; channel < numChromaticities(); ++channel)
  73     {
  74       logChromaticity[channel] = logf(chromaticities[channel]->buffer()[i]);
  75     }
  76
  77     // Find the dot of the chromaticity values with the illuminant direction vector
  78     float illuminant = logChromaticity * illuminantDirection();
  79
  80     // Subtract this * illuminant direction vector from original value to cancel out
  81     temp = illuminantDirection();
  82     temp *= illuminant;
  83     logChromaticity -= temp;
  84
  85     // Copy the data for now
  86     for (int channel = 0; channel < numChromaticities(); ++channel)
  87     {
  88       newChromaticityData[channel]->buffer()[i] = expf(logChromaticity[channel]);
  89     }
  90   }
  91 }