歐式聚類/聚類索引

#include <pcl/ModelCoefficients.h>
#include <pcl/point_types.h>
#include <pcl/io/pcd_io.h>
#include <pcl/filters/extract_indices.h>
#include <pcl/filters/voxel_grid.h>
#include <pcl/features/normal_3d.h>
#include <pcl/kdtree/kdtree.h>
#include <pcl/sample_consensus/method_types.h>
#include <pcl/sample_consensus/model_types.h>
#include <pcl/segmentation/sac_segmentation.h>
#include <pcl/segmentation/extract_clusters.h>


int 
main (int argc, char** argv)
{
  //讀入點雲數據table_scene_lms400.pcd
  pcl::PCDReader reader;
  pcl::PointCloud<pcl::PointXYZ>::Ptr cloud (new pcl::PointCloud<pcl::PointXYZ>), cloud_f (new pcl::PointCloud<pcl::PointXYZ>);
  reader.read ("table_scene_lms400.pcd", *cloud);
  std::cout << "PointCloud before filtering has: " << cloud->points.size () << " data points." << std::endl; //*
  /*從輸入的.PCD文件載入數據後,我們創建了一個VoxelGrid濾波器對數據進行下采樣,我們在這裏進行下采樣的原       因是來加速處理過程,越少的點意味着分割循環中處理起來越快。*/
  // Create the filtering object: downsample the dataset using a leaf size of 1cm
  pcl::VoxelGrid<pcl::PointXYZ> vg; //體素柵格下采樣對象
  pcl::PointCloud<pcl::PointXYZ>::Ptr cloud_filtered (new pcl::PointCloud<pcl::PointXYZ>);
  vg.setInputCloud (cloud);
  vg.setLeafSize (0.01f, 0.01f, 0.01f); //設置採樣的體素大小
  vg.filter (*cloud_filtered);  //執行採樣保存數據
  std::cout << "PointCloud after filtering has: " << cloud_filtered->points.size ()  << " data points." << std::endl; //*

  // Create the segmentation object for the planar model and set all the parameters
  pcl::SACSegmentation<pcl::PointXYZ> seg;//創建分割對象
  pcl::PointIndices::Ptr inliers (new pcl::PointIndices);
  pcl::ModelCoefficients::Ptr coefficients (new pcl::ModelCoefficients);
  pcl::PointCloud<pcl::PointXYZ>::Ptr cloud_plane (new pcl::PointCloud<pcl::PointXYZ> ());
  pcl::PCDWriter writer;
  seg.setOptimizeCoefficients (true);  //設置對估計的模型參數進行優化處理
  seg.setModelType (pcl::SACMODEL_PLANE);//設置分割模型類別
  seg.setMethodType (pcl::SAC_RANSAC);//設置用哪個隨機參數估計方法
  seg.setMaxIterations (100);  //設置最大迭代次數
  seg.setDistanceThreshold (0.02);    //設置判斷是否爲模型內點的距離閾值

  int i=0, nr_points = (int) cloud_filtered->points.size ();
  while (cloud_filtered->points.size () > 0.3 * nr_points)
  {
    // Segment the largest planar component from the remaining cloud
    /*爲了處理點雲中包含多個模型,我們在一個循環中執行該過程,並在每次模型被提取後,我們保存剩餘的點,進行迭代。模型內點通過分割過程獲取,如下*/
    seg.setInputCloud (cloud_filtered);
    seg.segment (*inliers, *coefficients);
    if (inliers->indices.size () == 0)
    {
      std::cout << "Could not estimate a planar model for the given dataset." << std::endl;
      break;
    }

    //移去平面局內點,提取剩餘點雲
    pcl::ExtractIndices<pcl::PointXYZ> extract;   //創建點雲提取對象
    extract.setInputCloud (cloud_filtered);    //設置輸入點雲
    extract.setIndices (inliers);   //設置分割後的內點爲需要提取的點集
    extract.setNegative (false); //設置提取內點而非外點
    // Get the points associated with the planar surface
    extract.filter (*cloud_plane);   //提取輸出存儲到cloud_plane
    std::cout << "PointCloud representing the planar component: " << cloud_plane->points.size () << " data points." << std::endl;

    // Remove the planar inliers, extract the rest
    extract.setNegative (true);
    extract.filter (*cloud_f);
    *cloud_filtered = *cloud_f;
  }

  // Creating the KdTree object for the search method of the extraction
  pcl::search::KdTree<pcl::PointXYZ>::Ptr tree (new pcl::search::KdTree<pcl::PointXYZ>);
  tree->setInputCloud (cloud_filtered); //創建點雲索引向量,用於存儲實際的點雲信息

  std::vector<pcl::PointIndices> cluster_indices;
  pcl::EuclideanClusterExtraction<pcl::PointXYZ> ec;
  ec.setClusterTolerance (0.02); //設置近鄰搜索的搜索半徑爲2cm
  ec.setMinClusterSize (100);//設置一個聚類需要的最少點數目爲100
  ec.setMaxClusterSize (25000);//設置一個聚類需要的最大點數目爲25000
  ec.setSearchMethod (tree);//設置點雲的搜索機制
  ec.setInputCloud (cloud_filtered);
  ec.extract (cluster_indices);//從點雲中提取聚類,並將點雲索引保存在cluster_indices中

  /*爲了從點雲索引向量中分割出每個聚類,必須迭代訪問點雲索引,每次創建一個新的點雲數據集,並且將所有當前聚類的點寫入到點雲數據集中。*/
  //迭代訪問點雲索引cluster_indices,直到分割出所有聚類
  int j = 0;
  for (std::vector<pcl::PointIndices>::const_iterator it = cluster_indices.begin (); it != cluster_indices.end (); ++it)
  {
    pcl::PointCloud<pcl::PointXYZ>::Ptr cloud_cluster (new pcl::PointCloud<pcl::PointXYZ>);
    //創建新的點雲數據集cloud_cluster,將所有當前聚類寫入到點雲數據集中
    for (std::vector<int>::const_iterator pit = it->indices.begin (); pit != it->indices.end (); ++pit)
      cloud_cluster->points.push_back (cloud_filtered->points[*pit]); //*
    cloud_cluster->width = cloud_cluster->points.size ();
    cloud_cluster->height = 1;
    cloud_cluster->is_dense = true;

    std::cout << "PointCloud representing the Cluster: " << cloud_cluster->points.size () << " data points." << std::endl;
    std::stringstream ss;
    ss << "cloud_cluster_" << j << ".pcd";
    writer.write<pcl::PointXYZ> (ss.str (), *cloud_cluster, false); //*
    j++;
  }

  return (0);
}

 

版權聲明:本文爲博主原創文章,遵循 CC 4.0 BY-SA 版權協議,轉載請附上原文出處鏈接和本聲明。
本文鏈接:https://blog.csdn.net/HERO_CJN/article/details/80172028
————————————————
版權聲明:本文爲CSDN博主「cjn_」的原創文章,遵循 CC 4.0 BY-SA 版權協議,轉載請附上原文出處鏈接及本聲明。
原文鏈接:https://blog.csdn.net/HERO_CJN/article/details/80172028

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