se_neighborhood.hh

// Copyright (C) 2001, 2002, 2003, 2004  EPITA Research and Development Laboratory
//
// This file is part of the Olena Library.  This library is free
// software; you can redistribute it and/or modify it under the terms
// of the GNU General Public License version 2 as published by the
// Free Software Foundation.
//
// 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
// General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this library; see the file COPYING.  If not, write to
// the Free Software Foundation, 59 Temple Place - Suite 330, Boston,
// MA 02111-1307, USA.
//
// As a special exception, you may use this file as part of a free
// software library without restriction.  Specifically, if other files
// instantiate templates or use macros or inline functions from this
// file, or you compile this file and link it with other files to
// produce an executable, this file does not by itself cause the
// resulting executable to be covered by the GNU General Public
// License.  This exception does not however invalidate any other
// reasons why the executable file might be covered by the GNU General
// Public License.

#ifndef OLENA_IO_SE_NEIGHBORHOOD_HH
# define OLENA_IO_SE_NEIGHBORHOOD_HH

# include <oln/core/image2d.hh>
# include <oln/core/neighborhood2d.hh>
# include <oln/core/macros.hh>
# include <oln/io/image.hh>

namespace oln {

  namespace io {

    namespace internal {

      inline bool
      read(neighborhood2d& output, const std::string& name)
      {
        image2d<ntg::bin> im;
        if (!read(im, name))
          return false;

        if (!(im.ncols() % 2) || !(im.nrows() % 2))
          {
            // std::clog << "[both image dimensions have to be odd for "
            //      << "a neighborhood2d]" << std::flush;
            return false;
          }
        image2d<ntg::bin>::fwd_iter_type it(im);
        neighborhood2d w;
        dpoint2d dcenter = dpoint2d(im.nrows()/2, im.ncols()/2);
        for_all (it)
          {
            if (it.row() == im.nrows()/2 && it.col() == im.ncols()/2+1)
              break;
            if (im[it])
              {
                dpoint2d dp = dpoint2d(it) - dcenter;
                if (dp.is_centered()) return false;
                w.add(dp);
              }
          }
        for_all_remaining (it)
          {
            point2d p = it - dcenter;
            point2d inv_p = -p + dcenter;
            if (im[it] != im[inv_p])
              {
                // std::clog << "[a neighborhood2d must be symmetric]"
                //  << std::flush;
                return false;
              }
          }
        output = w;
        return true;
      }

      inline bool
      write(const neighborhood2d& input, const std::string& name)
      {
        image2d<ntg::bin> im(input.delta()*2+1, input.delta()*2+1);
        image2d<ntg::bin>::fwd_iter_type it(im);
        for_all (it) im[it] = false;
        for (unsigned i = 0; i < input.card(); ++i)
          im[point2d(input.delta(),input.delta()) + input.dp(i)] = true;
        if (!write(im, name))
          return false;
        return true;
      }

    } // end of namespace internal

  } // end of namespace io

} // end of namespace oln

#endif // OLENA_IO_SE_NEIGHBORHOOD_HH

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