rag_and_labeled_wsl.hh

// Copyright (C) 2009 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_MAKE_RAG_AND_LABELED_WSL_HH
# define MLN_MAKE_RAG_AND_LABELED_WSL_HH


# include <map>

# include <mln/core/concept/image.hh>
# include <mln/core/concept/neighborhood.hh>
# include <mln/core/image/image2d.hh>
# include <mln/core/alias/box2d.hh>
# include <mln/extension/adjust_fill.hh>
# include <mln/util/graph.hh>
# include <mln/util/couple.hh>


namespace mln
{

  namespace make
  {


    template <typename I, typename N>
    util::couple<util::graph,mln_concrete(I)>
    rag_and_labeled_wsl(const Image<I>& wshd_,
                        const Neighborhood<N>& nbh_,
                        const mln_value(I)& nbasins);



# ifndef MLN_INCLUDE_ONLY


    namespace internal
    {

      template <typename I, typename N>
      inline
      void
      rag_and_labeled_wsl_tests(const Image<I>& wshd,
                                const Neighborhood<N>& nbh,
                                const mln_value(I)&)
      {
        mln_precondition(exact(wshd).is_valid());
        mln_precondition(exact(nbh).is_valid());
        (void) wshd;
        (void) nbh;
      }

    } // end of namespace mln::make::internal


    namespace impl
    {

      namespace generic
      {

        template <typename I, typename N>
        inline
        util::couple<util::graph,mln_concrete(I)>
        rag_and_labeled_wsl(const Image<I>& wshd_,
                            const Neighborhood<N>& nbh_,
                            const mln_value(I)& nbasins)
        {
          trace::entering("make::impl::generic::rag_and_labeled_wsl");

          internal::rag_and_labeled_wsl_tests(wshd_, nbh_, nbasins);
          const I& wshd = exact(wshd_);
          const N& nbh = exact(nbh_);
          typedef mln_value(I) L;

          extension::adjust_fill(wshd, nbh, 0u);

          mln_concrete(I) output(wshd.domain());

          // FIXME: we would like to not use mln_value() but 0 instead.
          // We can't do that because graph edges are numbered from 0.
          data::fill(output, mln_max(mln_value(I)).prev());

          std::map<util::couple<L,L>, mln_value(I)> c2la;
          util::array<util::couple<L,L> > la2c;
          mln_value(I) nlabels = literal::zero;

          L l1, l2;
          mln_piter(I) p(wshd.domain());
          mln_niter(N) n(nbh, p);
          for_all(p)
          {
            if (wshd(p) != 0u)
              continue;
            // p is in the watershed line.
            l1 = l2 = 0;
            for_all(n)
              if (wshd.has(n) && wshd(n) != 0u)
              {
                if (l1 == 0u) // First label to be stored.
                  l1 = wshd(n);
                else
                  if (wshd(n) != l1) // Useless: && l2 == 0)
                  { // Second label to be stored.
                    mln_invariant(l2 == 0u);
                    l2 = wshd(n);
                    break;
                  }
              }
            if (l2 == 0u || l1 == 0u)
              continue;
            if (l2 < l1)
              std::swap(l1, l2);

            // adjacency l1 l2
            util::couple<L,L> c = make::couple(l2,l1);
            if (c2la.find(c) == c2la.end())
            {
              c2la[c] = nlabels++;
              la2c.append(c);
            }
            output(p) = c2la[c];

          }

          // Construct graph.
          util::graph g;
          g.add_vertices(nbasins.next());
          for (unsigned i = 0; i < la2c.nelements(); ++i)
            g.add_edge(la2c[i].first(), la2c[i].second());

          trace::exiting("make::impl::generic::rag_and_labeled_wsl");
          return make::couple(g, output);
        }

      } // end of namespace mln::make::impl::generic

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



    namespace internal
    {

      template <typename I, typename N>
      inline
      util::couple<util::graph,mln_concrete(I)>
      rag_and_labeled_wsl_dispatch(const Image<I>& wshd,
                                   const Neighborhood<N>& nbh,
                                   const mln_value(I)& nbasins)
      {
        return make::impl::generic::rag_and_labeled_wsl(wshd, nbh, nbasins);
      }

    } // end of namespace mln::make::internal



    // Facade

    template <typename I, typename N>
    inline
    util::couple<util::graph,mln_concrete(I)>
    rag_and_labeled_wsl(const Image<I>& wshd,
                        const Neighborhood<N>& nbh,
                        const mln_value(I)& nbasins)
    {
      trace::entering("make::rag_and_labeled_wsl");

      internal::rag_and_labeled_wsl_tests(wshd, nbh, nbasins);

      util::couple<util::graph,mln_concrete(I)>
        result = internal::rag_and_labeled_wsl_dispatch(wshd, nbh, nbasins);

      trace::exiting("make::rag_and_labeled_wsl");
      return result;
    }


# endif // ! MLN_INCLUDE_ONLY


  } // end of namespace mln::make

} // end of namespace mln


#endif // ! MLN_MAKE_RAG_AND_LABELED_WSL_HH