STBReader.ih

/**
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU Lesser General Public License as
 *  published by the Free Software Foundation, either version 3 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 for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 **/
 
/**
 * @file STBReader.ih
 * @author David Coeurjolly (\c david.coeurjolly@liris.cnrs.fr )
 * Laboratoire d'InfoRmatique en Image et Systemes d'information - LIRIS (CNRS, UMR 5205), CNRS, France
 *
 * @date 2022/06/14
 *
 * Implementation of inline methods defined in STBReader.h
 *
 * This file is part of the DGtal library.
 */
 
#ifndef NO_ADD_STBIMAGE_IMPLEMENT //To avoid duplicated linking errors (like LNK2005 in MSVC)
#pragma once
#define STB_IMAGE_IMPLEMENTATION
#endif //NO_ADD_STBIMAGE_IMPLEMENT
#include <stb/stb_image.h>
 
///////////////////////////////////////////////////////////////////////////////
// Interface - public :
 
 
template <typename TImageContainer, typename TFunctor>
inline
TImageContainer
DGtal::STBReader<TImageContainer, TFunctor>::import(const std::string & filename,
                                                       const Functor & aFunctor)
{
  int x,y,n;
  unsigned char *data = stbi_load(filename.c_str(), &x, &y, &n, 0);
  
  typename TImageContainer::Point firstPoint(0,0);
  typename TImageContainer::Point lastPoint(x-1,y-1);
  
  typename TImageContainer::Domain domain(firstPoint,lastPoint);
  TImageContainer image(domain);
 
#ifdef VERBOSE
  trace.info()<<"File size= "<<x<<"x"<<y<<" nbChannels= "<< n<<std::endl;
#endif
  
  Color col;
  for(auto j=0; j < y; ++j)
    for(auto i=0; i < x; ++i)
    {
      const auto id = j*x+i;
      if (n==1)
        col.setRGBi(data[id],data[id],data[id],data[id]);
      else
        if (n==2)
          col.setRGBi(data[2*id],data[2*id],data[2*id],data[2*id+1]);
        else
          if (n==3)
            col.setRGBi(data[3*id],data[3*id+1],data[3*id+2],255);
          else
            col.setRGBi(data[4*id],data[4*id+1],data[4*id+2],data[4*id+3]);
      
      image.setValue(typename TImageContainer::Point(i,j), aFunctor(col) );
    }
  
  stbi_image_free(data);
  return image;
}
 
//                                                                           //
///////////////////////////////////////////////////////////////////////////////