make_complex2d.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.
//
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// 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 APPS_GRAPH_MORPHO_MAKE_COMPLEX2D_HH
# define APPS_GRAPH_MORPHO_MAKE_COMPLEX2D_HH


# include <mln/core/image/image2d.hh>
# include <mln/world/inter_pixel/dim2/is_pixel.hh>

template <typename I>
inline
mln_concrete(I)
make_complex2d(const mln::Image<I>& input_)
{
  using namespace mln;

  const I& input = exact(input_);
  /* FIXME: The construction of OUTPUT is obvioulsy not generic, since
     it expects I's domain to provide the interface of an mln::box2d.
     There should be a static precondition on I at the beginning of
     this function.  */
  typedef mln_concrete(I) O;
  O output(2 * input.nrows() - 1, 2 * input.ncols() - 1);

  mln_piter(O) p(output.domain());
  for_all(p)
  {
    point2d p_ = p;
    if (p_.row() % 2 == 0)
      {
        if (p_.col() % 2 == 0)
          // Pixel site.
          output(p) = input.at_(p_.row() / 2, p_.col() / 2);
        else
          // Horizontal edge site.
          output(p) =
            input.at_(p_.row() / 2, (p_.col() - 1) / 2) &&
            input.at_(p_.row() / 2, (p_.col() + 1) / 2);
      }
    else
      {
        if (p_.col() % 2 == 0)
          // Vertical edge site.
          output(p) =
            input.at_((p_.row() - 1) / 2, p_.col() / 2) &&
            input.at_((p_.row() + 1) / 2, p_.col() / 2);
        else
          // Square site (not handled, but still set for possible
          // debug outputs).
          output(p) = 
            input.at_((p_.row() - 1) / 2, (p_.col() - 1) / 2) &&
            input.at_((p_.row() - 1) / 2, (p_.col() + 1) / 2) &&
            input.at_((p_.row() + 1) / 2, (p_.col() - 1) / 2) &&
            input.at_((p_.row() + 1) / 2, (p_.col() + 1) / 2);
      }
  }
  return output;
}


template <typename I>
inline
mln_concrete(I)
unmake_complex2d(const mln::Image<I>& input_)
{
  using namespace mln;

  const I& input = exact(input_);
  // The input image must have an odd number of rows and columns.
  mln_precondition(input.nrows() % 2 == 1);
  mln_precondition(input.ncols() % 2 == 1);

  // Create a (morpher) image of the pixels of INPUT.
  typedef image_if< const I, world::inter_pixel::dim2::is_pixel > J;
  J input_pixels = input | world::inter_pixel::dim2::is_pixel();

  /* FIXME: The construction of OUTPUT is obvioulsy not generic, since
     it expects I's domain to provide the interface of an mln::box2d.
     There should be a static precondition on I at the beginning of
     this function.  */
  typedef mln_concrete(I) O;
  // FIXME: This won't work if INPUT's domain does not start at (0,0).
  O output(input.nrows() / 2 + 1, input.ncols() / 2 + 1);

  mln_piter(J) p_in(input_pixels.domain());
  mln_piter(O) p_out(output.domain());
  for_all_2(p_in, p_out)
    output(p_out) = input(p_in);
  return output;
}


#endif // ! APPS_GRAPH_MORPHO_MAKE_COMPLEX2D_HH