在图像上提升grid_graph和图形切割

2 回答

• 1

  你有另一个答案的问题可能是由旧版本的Visual Studio引起的（其代码适用于Visual Studio 2012 Express / g 4.8.0和boost 1.53.0） . 如果问题是您编译器中唯一的问题，则可以通过创建另一个类似于使用 capacity 的自定义属性映射来轻松回避这个问题 . 所需的更改标有 //ADDED 和 //CHANGED .

  #include <iostream>
  
  #include <boost/graph/grid_graph.hpp>
  #include <boost/graph/boykov_kolmogorov_max_flow.hpp>
  #include <boost/graph/iteration_macros.hpp>
  
  int main()
  {
  
      const unsigned int D = 2;
      typedef boost::grid_graph<D> Graph;
      typedef boost::graph_traits<Graph>::vertex_descriptor VertexDescriptor;
      typedef boost::graph_traits<Graph>::edge_descriptor EdgeDescriptor;//ADDED
      typedef boost::graph_traits<Graph>::vertices_size_type VertexIndex;
      typedef boost::graph_traits<Graph>::edges_size_type EdgeIndex;
  
  
      boost::array<std::size_t, D> lengths = { { 3, 3 } };
      Graph graph(lengths, false);
  
      float pixel_intensity[]={10.0f,15.0f,25.0f,
                              5.0f,220.0f,240.0f,
                              12.0f,15.0,230.0f};
      std::vector<int> groups(num_vertices(graph));
      std::vector<float> residual_capacity(num_edges(graph)); //this needs to be initialized to 0
      std::vector<float> capacity(num_edges(graph)); //this is initialized below, I believe the capacities of an edge and its reverse should be equal, but I'm not sure
      std::vector<EdgeDescriptor> reverse_edges(num_edges(graph));//ADDED
  
      BGL_FORALL_EDGES(e,graph,Graph)
      {
          VertexDescriptor src = source(e,graph);
          VertexDescriptor tgt = target(e,graph);
          VertexIndex source_idx = get(boost::vertex_index,graph,src);
          VertexIndex target_idx = get(boost::vertex_index,graph,tgt);
          EdgeIndex edge_idx = get(boost::edge_index,graph,e);
  
          capacity[edge_idx] = 255.0f - fabs(pixel_intensity[source_idx]-pixel_intensity[target_idx]); //you should change this to your "gradiant or intensity or something"
  
          reverse_edges[edge_idx]=edge(tgt,src,graph).first;//ADDED
      }
  
      VertexDescriptor s=vertex(0,graph), t=vertex(8,graph); 
  
      //in the boykov_kolmogorov_max_flow header it says that you should use this overload with an explicit color property map parameter if you are interested in finding the minimum cut
      boykov_kolmogorov_max_flow(graph,
          make_iterator_property_map(&capacity[0], get(boost::edge_index, graph)), 
          make_iterator_property_map(&residual_capacity[0], get(boost::edge_index, graph)),
          make_iterator_property_map(&reverse_edges[0], get(boost::edge_index, graph)), //CHANGED
          make_iterator_property_map(&groups[0], get(boost::vertex_index, graph)),
          get(boost::vertex_index, graph),
          s,
          t
      );
  
  
     for(size_t index=0; index < groups.size(); ++index)
     {
          if((index%lengths[0]==0)&&index)
              std::cout << std::endl;
          std::cout << groups[index] << " ";
     }
  
     return 0;
  }
  

  Working on Coliru.

  PS：Boost.Graph文档无法澄清的一件事是，当您明确传递每个参数时，这里描述的概念要求适用于这种情况 . 一些默认参数可能会引入进一步的要求 .

  回复于 2024-05-10T11:30:02+08:00
• 5

  #include <iostream>
  
  #include <boost/graph/grid_graph.hpp>
  #include <boost/graph/boykov_kolmogorov_max_flow.hpp>
  #include <boost/graph/iteration_macros.hpp>
  
  int main()
  {
  
      const unsigned int D = 2;
      typedef boost::grid_graph<D> Graph;
      typedef boost::graph_traits<Graph>::vertex_descriptor VertexDescriptor;
      typedef boost::graph_traits<Graph>::vertices_size_type VertexIndex;
      typedef boost::graph_traits<Graph>::edges_size_type EdgeIndex;
  
  
      boost::array<unsigned int, D> lengths = { { 3, 3 } };
      Graph graph(lengths, false);
  
      float pixel_intensity[]={10.0f,15.0f,25.0f,
                              5.0f,220.0f,240.0f,
                              12.0f,15.0,230.0f};
      std::vector<int> groups(num_vertices(graph));
      std::vector<float> residual_capacity(num_edges(graph)); //this needs to be initialized to 0
      std::vector<float> capacity(num_edges(graph)); //this is initialized below, I believe the capacities of an edge and its reverse should be equal, but I'm not sure
  
      BGL_FORALL_EDGES(e,graph,Graph)
      {
          VertexDescriptor src = source(e,graph);
          VertexDescriptor tgt = target(e,graph);
          VertexIndex source_idx = get(boost::vertex_index,graph,src);
          VertexIndex target_idx = get(boost::vertex_index,graph,tgt);
          EdgeIndex edge_idx = get(boost::edge_index,graph,e);
          capacity[edge_idx] = 255.0f - fabs(pixel_intensity[source_idx]-pixel_intensity[target_idx]); //you should change this to your "gradiant or intensity or something"
      }
  
      VertexDescriptor s=vertex(0,graph), t=vertex(8,graph); 
  
      //in the boykov_kolmogorov_max_flow header it says that you should use this overload with an explicit color property map parameter if you are interested in finding the minimum cut
      boykov_kolmogorov_max_flow(graph,
          make_iterator_property_map(&capacity[0], get(boost::edge_index, graph)), 
          make_iterator_property_map(&residual_capacity[0], get(boost::edge_index, graph)),
          get(boost::edge_reverse, graph),
          make_iterator_property_map(&groups[0], get(boost::vertex_index, graph)),
          get(boost::vertex_index, graph),
          s,
          t
      );
  
  
     for(size_t index=0; index < groups.size(); ++index)
     {
          if((index%lengths[0]==0)&&index)
              std::cout << std::endl;
          std::cout << groups[index] << " ";
     }
  
     return 0;
  }
  

  回复于 2024-05-10T11:30:02+08:00