Processing frontp_connected_component extract the connected components.
It removes the small (in area) connected components of the upper level sets of input using se as structural element.
REF: The implementation uses front propagation.
- Precondition:
- the input must be a binary image.
- input Image of markers.
- se Neighbourhood.
- nb_label Returns the number of label (optional).
- Returns:
- An image of type DestType.
- See also:
- level::connected_component
- Todo:
- FIXME: Should probably be turned into a class.
#include <oln/basics2d.hh> #include <oln/level/cc.hh> #include <ntg/all.hh> #include <iostream> int main() { unsigned card; oln::image2d<ntg::bin> light = oln::load(IMG_IN "face_se.pbm"); save(oln::level::frontp_connected_component<ntg::int_u8>(light, oln::neighb_c8(), card), IMG_OUT "oln_level_frontp_connected_component.pgm"); std::cout << card << " connected components" << std::endl; }
Definition at line 96 of file cc.hh.
References oln::abstract::image< Exact >::hold(), and oln::abstract::image< Exact >::size().
00099 {
00100 typename mute<I, DestType>::ret output(input.size());
00101 level::fill(output, 0);
00102
00103 typedef std::set<oln_point_type(I),
00104 oln::internal::default_less<oln_point_type(I) > >
00105 points_set;
00106
00107 I is_processed(input.size());
00108 level::fill(is_processed, false);
00109 DestType cur_label = 1;
00110 oln_iter_type(I) p(input);
00111 for_all(p) if ((input[p] == true)&& (is_processed[p] == false))
00112 {
00113 //propagation front
00114 points_set component;
00115 component.insert(p.cur());
00116 points_set points_to_process;
00117 points_to_process.insert(p.cur());
00118 while (!points_to_process.empty())
00119 {
00120 //set label and net neighbors
00121 points_set next;
00122 for (typename points_set::const_iterator i =
00123 points_to_process.begin();
00124 i != points_to_process.end();
00125 ++i)
00126 {
00127 component.insert(*i);
00128 oln_neighb_type(E) p_prime(se, *i);
00129 for_all (p_prime) if(input.hold(p_prime) &&
00130 (input[p_prime] == true))
00131 next.insert(p_prime.cur());
00132 }
00133 points_to_process.clear();
00134 set_difference(next.begin(), next.end(),
00135 component.begin(), component.end(),
00136 inserter(points_to_process,
00137 points_to_process.begin()),
00138 oln::internal::default_less<oln_point_type(I) >());
00139 }
00140 for (typename points_set::const_iterator i = component.begin();
00141 i != component.end();
00142 ++i)
00143 {
00144 output[*i] = cur_label;
00145 is_processed[*i] = true;
00146 }
00147 cur_label++;
00148 }
00149 nb_label = cur_label;
00150 return output;
00151 }
