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An Image Processing Platform
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priority_driven_thinning.cc
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25 
29 
30 #include <mln/core/image/image2d.hh>
31 #include <mln/core/alias/neighb2d.hh>
32 
33 #include <mln/topo/skeleton/priority_driven_thinning.hh>
34 
35 #include <mln/topo/is_simple_point2d.hh>
36 #include <mln/topo/detach_point.hh>
37 
38 #include <mln/logical/not.hh>
39 #include <mln/arith/revert.hh>
40 #include <mln/transform/distance_geodesic.hh>
41 
42 #include <mln/io/pbm/all.hh>
43 
44 #include "tests/data.hh"
45 
46 
47 int main()
48 {
49  using namespace mln;
50 
51  typedef image2d<bool> I;
52  typedef neighb2d N;
53 
54  // Add a border of (at least) 1 pixel, to a guarantee a meaningful
55  // result of the computation of connectivity numbers (called within
56  // is_simple_2d); indeed, this computation always expects each pixel
57  // to have 8 neighboring sites.
59 
60  I input = io::pbm::load(MLN_IMG_DIR "/small.pbm");
61 
62  // FIXME: Use a dual neighborhood instead?
63 
64  // Foreground neighborhood.
65  neighb2d nbh_fg = c4();
66  // Background neighborhood.
67  neighb2d nbh_bg = c8();
68 
69  // Simplicity criterion functor.
70  topo::is_simple_point2d<I, N> is_simple(nbh_fg, nbh_bg);
71  // Simple point detach procedure.
72  topo::detach_point<I> detach;
73 
74  // Distance type.
75  typedef value::int_u8 D;
76  // Distance map type.
77  typedef image2d<D> M;
78 
79  // Compute a distance map on the objects (foreground) of the image,
80  // instead of the (usual) background.
81  M dmap = transform::distance_geodesic(logical::not_(input), nbh_fg,
82  mln_max(D));
83  // Create a priority function (actually, an image) using the inverse
84  // of the distance map.
85  M priority = arith::revert(dmap);
86 
87  I output = topo::skeleton::priority_driven_thinning(input, nbh_fg,
88  is_simple,
89  detach,
90  priority);
91  io::pbm::save(output, "priority_driven_thinning-small.pbm");
92 }