blobs.hh

// Copyright (C) 2007, 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_LABELING_BLOBS_HH
# define MLN_LABELING_BLOBS_HH


# include <mln/core/concept/image.hh>
# include <mln/core/concept/neighborhood.hh>
# include <mln/data/fill.hh>
# include <mln/core/site_set/p_queue_fast.hh>



namespace mln
{

  namespace labeling
  {

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


# ifndef MLN_INCLUDE_ONLY

    namespace impl
    {

      namespace generic
      {

        template <typename I, typename N, typename L>
        mln_ch_value(I, L)
          blobs_(const I& input, const N& nbh, L& nlabels)
        {
          typedef mln_psite(I) P;

          P cur;
          mln_niter(N) n(nbh, cur);
          p_queue_fast<P> qu;
          const L zero = literal::zero;

          // Initialization.
          nlabels = literal::zero;
          mln_ch_value(I, L) output;
          initialize(output, input);
          data::fill(output, zero);

          // Loop.
          mln_piter(I) p(input.domain());
          for_all(p)
            if (input(p) && output(p) == zero) // Object point, not labeled yet.
              {
                // Label this point component.
                if (nlabels == mln_max(L))
                  {
                    trace::warning("labeling aborted! Too many labels \
for this label type: nlabels > max(label_type).");

                    return output;
                  }
                ++nlabels;
                mln_invariant(qu.is_empty());
                qu.push(p);
                output(p) = nlabels;
                do
                  {
                    cur = qu.front();
                    qu.pop();
                    for_all(n) if (input.has(n))
                      if (input(n) && output(n) == zero)
                        {
                          mln_invariant(! qu.compute_has(n));
                          qu.push(n);
                          output(n) = nlabels;
                        }
                  }
                while (! qu.is_empty());
              }

          return output;
        }

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


      template <typename I, typename N, typename L>
      mln_ch_value(I, L)
        blobs_(const I& input, const N& nbh, L& nlabels)
      {
        // The only implementation is the generic one.
        return generic::blobs_(input, nbh, nlabels);
      }

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


    // Facade.

    template <typename I, typename N, typename L>
    inline
    mln_ch_value(I, L)
    blobs(const Image<I>& input_, const Neighborhood<N>& nbh_,
          L& nlabels)
    {
      trace::entering("labeling::blobs");
      mlc_equal(mln_trait_image_kind(I),
                mln::trait::image::kind::binary)::check();
      const I& input = exact(input_);
      const N& nbh = exact(nbh_);
      mln_precondition(input.is_valid());

      mln_ch_value(I, L) output = impl::blobs_(input, nbh, nlabels);

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

# endif // ! MLN_INCLUDE_ONLY

  } // end of namespace mln::labeling

} // end of namespace mln


#endif // ! MLN_LABELING_BLOBS_HH