flat_zones.hh

// Copyright (C) 2007, 2008, 2009, 2010 EPITA Research and Development
// Laboratory (LRDE)
//
// This file is part of Olena.
//
// Olena is free software: you can redistribute it and/or modify it under
// the terms of the GNU General Public License as published by the Free
// Software Foundation, version 2 of the License.
//
// Olena 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 Olena.  If not, see <http://www.gnu.org/licenses/>.
//
// As a special exception, you may use this file as part of a free
// software project 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 MLN_LABELING_FLAT_ZONES_HH
# define MLN_LABELING_FLAT_ZONES_HH


# include <mln/core/concept/image.hh>
# include <mln/core/concept/neighborhood.hh>
# include <mln/canvas/labeling/video.hh>


namespace mln
{

  namespace labeling
  {

    template <typename I, typename N, typename L>
    mln_ch_value(I, L)
    flat_zones(const Image<I>& input, const Neighborhood<N>& nbh,
               L& nlabels);



# ifndef MLN_INCLUDE_ONLY

    namespace impl
    {

      // Flat zone functor for the labeling canvas.

      template <typename I, typename L>
      struct flat_zones_functor
      {
        const I& input;

        // Generic implementation.

        typedef mln_psite(I) P;

        void init()                          {}
        bool handles(const P&) const         { return true; }

        bool equiv(const P& n, const P& p) const
        { return input(n) == input(p); }

        bool labels(const P&) const          { return true;  }
        void do_no_union(const P&, const P&) {}
        void init_attr(const P&)             {}
        void merge_attr(const P&, const P&)  {}
        void set_new_label(const P& p, const L& l){}
        void set_label(const P& p, const L& l)    {}
        void finalize()                           {}


        // Fastest implementation.

        void init_()                          {}

        bool handles_(unsigned) const
        { return true; }

        bool equiv_(unsigned n, unsigned p) const
        { return input.element(n) == input.element(p); }

        bool labels_(unsigned) const          { return true;  }
        void do_no_union_(unsigned, unsigned) {}
        void init_attr_(unsigned)             {}
        void merge_attr_(unsigned, unsigned)  {}
        void set_new_label_(unsigned, const L&)   {}
        void set_label_(unsigned, const L&)       {}
        void finalize_()                          {}

        // end of requirements.

        flat_zones_functor(const I& input)
          : input(input)
        {}
      };


    } // end of namespace mln::labeling::impl



    // Facade.

    template <typename I, typename N, typename L>
    mln_ch_value(I, L)
    flat_zones(const Image<I>& input_, const Neighborhood<N>& nbh_,
               L& nlabels)
    {
      trace::entering("labeling::flat_zones");

      const I& input = exact(input_);
      const N& nbh = exact(nbh_);
      mln_precondition(input.is_valid());

      // Call the labeling canvas.
      typedef impl::flat_zones_functor<I,L> F;
      F f(input);
      mln_ch_value(I, L)
        output = canvas::labeling::video(input, nbh, nlabels, f);

      trace::exiting("labeling::flat_zones");
      return output;
    }

# endif // ! MLN_INCLUDE_ONLY

  } // end of namespace mln::labeling

} // end of namespace mln


#endif // ! MLN_LABELING_FLAT_ZONES_HH