mapnik/src/image_util.cpp

/*****************************************************************************
 * 
 * This file is part of Mapnik (c++ mapping toolkit)
 *
 * Copyright (C) 2006 Artem Pavlenko
 *
 * This library 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 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 *****************************************************************************/

//$Id: image_util.cpp 36 2005-04-05 14:32:18Z pavlenko $

extern "C"
{
#include <png.h>
}

// mapnik
#include <mapnik/image_util.hpp>
#include <mapnik/png_io.hpp>
#include <mapnik/jpeg_io.hpp>
#include <mapnik/graphics.hpp>
#include <mapnik/memory.hpp>
#include <mapnik/image_view.hpp>

// stl
#include <string>
#include <iostream>
#include <fstream>
#include <sstream>

namespace mapnik
{    
   template <typename T>
   std::string save_to_string(T const& image,
                     std::string const& type)
   {
      std::ostringstream ss(std::ios::out|std::ios::binary);
     //all this should go into image_writer factory
     if (type=="png")  save_as_png(ss,image);
     else if (type == "png256") save_as_png256(ss,image);
     else if (boost::algorithm::istarts_with(type,std::string("jpeg")))
	 {
	   int quality = 85;
	   try 
	   {
		  if(type.substr(4).length() != 0)
		  {
		     quality = boost::lexical_cast<int>(type.substr(4));
			 if(quality<1 || quality>100)
				  throw ImageWriterException("invalid jpeg quality: " + type.substr(4));
		  }
	      save_as_jpeg(ss,quality,image); 
	   } 
	   catch(boost::bad_lexical_cast &)
       {
          throw ImageWriterException("invalid jpeg quality: " + type.substr(4));
       }
   }
     else throw ImageWriterException("unknown file type: " + type);
     return ss.str();
   }

   template <typename T>
   void save_to_file(T const& image,
                     std::string const& filename,
                     std::string const& type)
   {
      std::ofstream file (filename.c_str(), std::ios::out| std::ios::trunc|std::ios::binary);
      if (file)
      {
         //all this should go into image_writer factory
         if (type=="png")  save_as_png(file,image);
         else if (type == "png256") save_as_png256(file,image);
		  else if (boost::algorithm::istarts_with(type,std::string("jpeg")))
		  {
			  int quality = 85;
			  try 
			  {
				  if(type.substr(4).length() != 0)
				  {
					  quality = boost::lexical_cast<int>(type.substr(4));
					  if(quality<0 || quality>100)
						  throw ImageWriterException("invalid jpeg quality: " + type.substr(4) + " out of bounds");
				  }
				  save_as_jpeg(file,quality,image); 
			  } 
			  catch(boost::bad_lexical_cast &)
			  {
				  throw ImageWriterException("invalid jpeg quality: " + type.substr(4) + " not a number");
			  }
		  }
		  else throw ImageWriterException("unknown file type: " + type);
	  } 
   }
	
   template <typename T>
   void save_to_file(T const& image,std::string const& filename)
   {
      std::string type = type_from_filename(filename);
      save_to_file<T>(image,filename,type);
   }
     

   template void save_to_file<ImageData32>(ImageData32 const&,
                                           std::string const&,
                                           std::string const&);

   template void save_to_file<ImageData32>(ImageData32 const&,
                                           std::string const&);

   template std::string save_to_string<ImageData32>(ImageData32 const&,
                                           std::string const&);

   template void save_to_file<image_view<ImageData32> > (image_view<ImageData32> const&,
                                                         std::string const&,
                                                         std::string const&);
   
   template void save_to_file<image_view<ImageData32> > (image_view<ImageData32> const&,
                                                         std::string const&);
   
   template std::string save_to_string<image_view<ImageData32> > (image_view<ImageData32> const&,
                                                         std::string const&);

}