flooding.hh

// Copyright (C) 2008, 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_MORPHO_WATERSHED_FLOODING_HH
# define MLN_MORPHO_WATERSHED_FLOODING_HH


# include <mln/trait/ch_value.hh>

# include <mln/morpho/includes.hh>
# include <mln/literal/zero.hh>
# include <mln/labeling/regional_minima.hh>

# include <mln/core/site_set/p_queue_fast.hh>
# include <mln/core/site_set/p_priority.hh>

# include <mln/extension/adjust_fill.hh>


namespace mln
{

  namespace morpho
  {

    namespace watershed
    {


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

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



# ifndef MLN_INCLUDE_ONLY


      // Implementations.

      namespace impl
      {

        namespace generic
        {

          template <typename L, typename I, typename N>
          mln_ch_value(I, L)
          flooding(const Image<I>& input_, const Neighborhood<N>& nbh_,
                   L& n_basins)
          {
            trace::entering("morpho::watershed::impl::generic::flooding");
            /* FIXME: Ensure the input image has scalar values.  */

            const I input = exact(input_);
            const N nbh = exact(nbh_);

            typedef L marker;
            const marker unmarked = literal::zero;

            typedef mln_value(I) V;
            const V max = mln_max(V);

            // Initialize the output with the markers (minima components).
            mln_ch_value(I, marker) output =
              labeling::regional_minima (input, nbh, n_basins);

            typedef mln_psite(I) psite;

            // Ordered queue.
            typedef p_queue_fast<psite> Q;
            p_priority<V, Q> queue;

            // In_queue structure to avoid processing sites several times.
            mln_ch_value(I, bool) in_queue;
            initialize(in_queue, input);
            data::fill(in_queue, false);

            // Insert every neighbor P of every marked area in a
            // hierarchical queue, with a priority level corresponding to
            // the grey level input(P).
            mln_piter(I) p(output.domain());
            mln_niter(N) n(nbh, p);
            for_all(p)
              if (output(p) == unmarked)
                for_all(n)
                  if (output.domain().has(n) && output(n) != unmarked)
                    {
                      queue.push(max - input(p), p);
                      in_queue(p) = true;
                      break;
                    }

            /* Until the queue is empty, extract a psite P from the
               hierarchical queue, at the highest priority level, that is,
               the lowest level.  */
            while (! queue.is_empty())
              {
                psite p = queue.front();
                queue.pop();

                // Last seen marker adjacent to P.
                marker adjacent_marker = unmarked;
                // Has P a single adjacent marker?
                bool single_adjacent_marker_p = true;
                mln_niter(N) n(nbh, p);
                for_all(n)
                  if (output.domain().has(n) && output(n) != unmarked)
                    {
                      if (adjacent_marker == unmarked)
                        {
                          adjacent_marker = output(n);
                          single_adjacent_marker_p = true;
                        }
                      else
                        if (adjacent_marker != output(n))
                          {
                            single_adjacent_marker_p = false;
                            break;
                          }
                    }
                /* If the neighborhood of P contains only psites with the
                   same label, then P is marked with this label, and its
                   neighbors that are not yet marked are put into the
                   hierarchical queue.  */
                if (single_adjacent_marker_p)
                  {
                    output(p) = adjacent_marker;
                    for_all(n)
                      if (output.domain().has(n) && output(n) == unmarked
                          && ! in_queue(n))
                        {
                          queue.push(max - input(n), n);
                          in_queue(n) = true;
                        }
                  }
              }

            trace::exiting("morpho::watershed::impl::generic::flooding");
            return output;
          }

        } // end of namespace mln::morpho::watershed::impl::generic



        // Fastest version.

        template <typename I, typename N, typename L>
        mln_ch_value(I, L)
        flooding_fastest(const Image<I>& input_, const Neighborhood<N>& nbh_,
                         L& n_basins)
        {
          trace::entering("morpho::watershed::impl::flooding_fastest");
          /* FIXME: Ensure the input image has scalar values.  */

          const I input = exact(input_);
          const N nbh = exact(nbh_);

          typedef L marker;
          const marker unmarked = literal::zero;

          typedef mln_value(I) V;
          const V max = mln_max(V);

          extension::adjust_fill(input, nbh, max);

          // Initialize the output with the markers (minima components).
          typedef mln_ch_value(I, L) O;
          O output = labeling::regional_minima(input, nbh, n_basins);
          extension::fill(output, unmarked);

          // Ordered queue.
          typedef p_queue_fast<unsigned> Q;
          p_priority<V, Q> queue;

          // FIXME:  With  typedef std::pair<V, unsigned> VU;
          //               std::priority_queue<VU> queue;
          // we do not get the same results!!!

          // In_queue structure to avoid processing sites several times.
          mln_ch_value(I, bool) in_queue;
          initialize(in_queue, input);
          data::fill(in_queue, false);
          extension::fill(in_queue, true);

          // Insert every neighbor P of every marked area in a
          // hierarchical queue, with a priority level corresponding to
          // the grey level input(P).
          mln_pixter(const O)    p_out(output);
          mln_nixter(const O, N) n_out(p_out, nbh);
          for_all(p_out)
            if (p_out.val() == unmarked)
              for_all(n_out)
                if (n_out.val() != unmarked)
                  {
                    unsigned po = p_out.offset();
                    queue.push(max - input.element(po), po);
                    in_queue.element(po) = true;
                    break;
                  }

          /* Until the queue is empty, extract a psite P from the
             hierarchical queue, at the highest priority level, that is,
             the lowest level.  */
          util::array<int> dp = offsets_wrt(input, nbh);
          const unsigned n_nbhs = dp.nelements();
          while (! queue.is_empty())
            {
              unsigned p = queue.front();
              queue.pop();

              // Last seen marker adjacent to P.
              marker adjacent_marker = unmarked;
              // Has P a single adjacent marker?
              bool single_adjacent_marker_p = true;
              for (unsigned i = 0; i < n_nbhs; ++i)
                {
                  unsigned n = p + dp[i];
                  // In the border, output is unmarked so N is ignored.
                  if (output.element(n) != unmarked)
                    {
                      if (adjacent_marker == unmarked)
                        {
                          adjacent_marker = output.element(n);
                          single_adjacent_marker_p = true;
                        }
                      else
                        if (adjacent_marker != output.element(n))
                          {
                            single_adjacent_marker_p = false;
                            break;
                          }
                    }
                }
              /* If the neighborhood of P contains only psites with the
                 same label, then P is marked with this label, and its
                 neighbors that are not yet marked are put into the
                 hierarchical queue.  */
              if (single_adjacent_marker_p)
                {
                  output.element(p) = adjacent_marker;
                  for (unsigned i = 0; i < n_nbhs; ++i)
                    {
                      unsigned n = p + dp[i];
                      if (output.element(n) == unmarked
                          // In the border, in_queue is true so N is ignored.
                          && ! in_queue.element(n))
                        {
                          queue.push(max - input.element(n), n);
                          in_queue.element(n) = true;
                        }
                    }
                }
            }

          trace::exiting("morpho::watershed::impl::flooding_fastest");
          return output;
        }


      } // end of namespace mln::morpho::watershed::impl



      // Dispatch.

      namespace internal
      {

        template <typename I, typename N, typename L>
        inline
        mln_ch_value(I, L)
        flooding_dispatch(metal::false_,
                          const Image<I>& input, const Neighborhood<N>& nbh,
                          L& n_basins)
        {
          return impl::generic::flooding(input, nbh, n_basins);
        }


        template <typename I, typename N, typename L>
        inline
        mln_ch_value(I, L)
        flooding_dispatch(metal::true_,
                          const Image<I>& input, const Neighborhood<N>& nbh,
                          L& n_basins)
        {
          return impl::flooding_fastest(input, nbh, n_basins);
        }

        template <typename I, typename N, typename L>
        inline
        mln_ch_value(I, L)
        flooding_dispatch(const Image<I>& input, const Neighborhood<N>& nbh,
                          L& n_basins)
        {
          enum {
            test = mlc_equal(mln_trait_image_speed(I),
                             trait::image::speed::fastest)::value
            &&
            mln_is_simple_neighborhood(N)::value
          };
          return flooding_dispatch(metal::bool_<test>(),
                                   input, nbh, n_basins);
        }

      } // end of namespace mln::morpho::watershed::internal


      // Facades.

      template <typename L, typename I, typename N>
      inline
      mln_ch_value(I, L)
      flooding(const Image<I>& input, const Neighborhood<N>& nbh, L& n_basins)
      {
        trace::entering("morpho::watershed::flooding");

        // FIXME: internal::flooding_tests(input, nbh, n_basins);

        mln_ch_value(I, L) output =
          internal::flooding_dispatch(input, nbh, n_basins);

        trace::exiting("morpho::watershed::flooding");
        return output;
      }

    template <typename L, typename I, typename N>
    mln_ch_value(I, L)
    flooding(const Image<I>& input, const Neighborhood<N>& nbh)
    {
      L nbasins;
      return flooding<L>(input, nbh, nbasins);
    }

# endif // ! MLN_INCLUDE_ONLY

    } // end of namespace mln::morpho::watershed

  } // end of namespace mln::morpho

} // end of namespace mln


#endif // ! MLN_MORPHO_WATERSHED_FLOODING_HH

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