[Olena-patches] cleanup-2008 2721: Add a distance by propagation sample code.

https://svn.lrde.epita.fr/svn/oln/branches/cleanup-2008/milena/sandbox Index: ChangeLog from Thierry Geraud &lt;thierry.geraud(a)lrde.epita.fr&gt; Add a distance by propagation sample code. * geraud/skel.cc: New. skel.cc | 104 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 104 insertions(+) Index: geraud/skel.cc --- geraud/skel.cc (revision 0) +++ geraud/skel.cc (revision 0) @@ -0,0 +1,104 @@ +# include <mln/core/var.hh> + +# include <mln/core/image/image2d.hh> +# include <mln/core/alias/neighb2d.hh> +# include <mln/core/site_set/p_queue_fast.hh> + +# include <mln/io/pbm/load.hh> +# include <mln/io/pgm/save.hh> +# include <mln/value/int_u8.hh> + +# include <mln/level/fill.hh> + +# include <mln/debug/println.hh> + + +namespace mln +{ + + template <typename D, typename I, typename N> + mln_ch_value(I, D) + distance(D, const I& input, const N& nbh) + { + const D M = mln_max(D); + mln_ch_value(I, D) output; + initialize(output, input); + + mln_ch_value(I, bool) deja_vu; + initialize(deja_vu, input); + level::fill(deja_vu, input); + + typedef mln_site(I) P; + p_queue_fast<P> q; + + // Initialization. + { + level::fill(output, M); + mln_piter(I) p(input.domain()); + mln_niter(N) n(nbh, p); + for_all(p) + if (input(p) == true) // p in object + { + output(p) = 0; + for_all(n) + if (input.domain().has(n) && input(n) == false) // n in background + { + q.push(p); + break; + } + } + } + + // Propagation. + { + P p; + mln_niter(N) n(nbh, p); + while (! q.is_empty()) + { + p = q.pop_front(); + for_all(n) + if (input.domain().has(n) && output(n) == M) + { + output(n) = output(p) + 1; + if (output(n) == M) + { + // Saturation so stop. + q.clear(); + break; + } + q.push(n); + deja_vu(n) = true; + } + } + } + + return output; + } + + +} // mln + + + +void usage(char* argv[]) +{ + std::cerr << "usage: " << argv[0] << " input.pbm output.pgm" << std::endl; + abort(); +} + + + +int main(int argc, char* argv[]) +{ + using namespace mln; + using value::int_u8; + + if (argc != 3) + usage(argv); + + image2d<bool> input; + io::pbm::load(input, argv[1]); + + image2d<int_u8> output = distance(int_u8(), input, c4()); + io::pgm::save(output, argv[2]); +}