erosion.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_MORPHO_APPROX_EROSION_HH
# define MLN_MORPHO_APPROX_EROSION_HH


# include <mln/morpho/approx/dilation.hh>
# include <mln/logical/not.hh>



namespace mln
{

  namespace morpho
  {

    namespace approx
    {


      template <typename I, typename W>
      mln_concrete(I)
      erosion(const Image<I>& input, const Window<W>& win);



# ifndef MLN_INCLUDE_ONLY


      // Implementations.

      namespace impl
      {
        
        
        // By distance thresholding.
        
        template <typename I>
        mln_concrete(I)
        erosion_by_distance_thresholding_2d(const Image<I>& input_,
                                             const Window< win::disk2d >& win_)
        {
          trace::entering("morpho::approx::impl::erosion_by_distance_thresholding_2d");

          const I& input         = exact(input_);
          const win::disk2d& win = exact(win_);

          mln_precondition(input.is_valid());
          mln_precondition(win.is_valid());

          int ws[] = { 00, 11,  0, 11,  0,
                       11,  7,  5,  7, 11,
                       00,  5,  0,  5,  0,
                       11,  7,  5,  7, 11,
                       00, 11,  0, 11,  0 };
          const unsigned coef = 5;

          unsigned
            radius = coef * win.diameter() / 2,
            dmax   = radius + 1;
          

          mln_concrete(I) background = logical::not_(input);
          mln_ch_value(I, unsigned) dmap = transform::distance_front(background,
                                                                     c4(), make::w_window2d_int(ws),
                                                                     dmax);
          mln_concrete(I) output;
          output = duplicate((pw::value(dmap) > pw::cst(radius)) | input.domain());

          trace::exiting("morpho::approx::impl::erosion_by_distance_thresholding_2d");
          return output;
        }


        
        template <typename I>
        mln_concrete(I)
        erosion_by_distance_thresholding_3d(const Image<I>& input_,
                                             const Window< win::sphere3d >& win_)
        {
          trace::entering("morpho::approx::impl::erosion_by_distance_thresholding_3d");

          const I& input           = exact(input_);
          const win::sphere3d& win = exact(win_);

          mln_precondition(input.is_valid());
          mln_precondition(win.is_valid());

          int ws[] = { 00, 21, 00,
                       21, 17, 21,
                       00, 21, 00,

                       17, 12, 17,
                       12, 00, 12,
                       17, 12, 17,

                       00, 21, 00,
                       21, 17, 21,
                       00, 21, 00 };
          const unsigned coef = 12;

          unsigned
            radius = coef * win.diameter() / 2,
            dmax   = radius + 1;

          mln_concrete(I) background = logical::not_(input);
          mln_ch_value(I, unsigned) dmap = transform::distance_front(background,
                                                                     c6(), make::w_window3d_int(ws),
                                                                     dmax);
          mln_concrete(I) output;
          output = duplicate((pw::value(dmap) > pw::cst(radius)) | input.domain());

          trace::exiting("morpho::approx::impl::erosion_by_distance_thresholding_3d");
          return output;
        }


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



      // Dispatch.

      namespace internal
      {

        template <typename I>
        mln_concrete(I)
        erosion_dispatch(trait::image::kind::logic,
                          const I& input,
                          const win::disk2d& win)
        {
          return impl::erosion_by_distance_thresholding_2d(input, win);
        }

        template <typename I>
        mln_concrete(I)
        erosion_dispatch(trait::image::kind::logic,
                          const I& input,
                          const win::sphere3d& win)
        {
          return impl::erosion_by_distance_thresholding_3d(input, win);
        }

        // Entry point.

        template <typename I, typename W>
        mln_concrete(I)
        erosion_dispatch(const I& input, const W& win)
        {
          return erosion_dispatch(mln_trait_image_kind(I)(),
                                   input, win);
        }

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


      // Facade.

      template <typename I, typename W>
      inline
      mln_concrete(I)
      erosion(const Image<I>& input, const Window<W>& win)
      {
        trace::entering("morpho::approx::erosion");

        mln_precondition(exact(input).is_valid());
        mln_precondition(exact(win).is_valid());

        mln_concrete(I) output;
        output = internal::erosion_dispatch(exact(input), exact(win));

        if (exact(win).is_centered())
          mln_postcondition(output <= input);
        
        trace::exiting("morpho::approx::erosion");
        return output;
      }


# endif // ! MLN_INCLUDE_ONLY

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

  } // end of namespace mln::morpho

} // end of namespace mln


#endif // ! MLN_MORPHO_APPROX_EROSION_HH