PCL中利用ExtractIndices按点云索引提取点云子集

点云操作过程中经常会需要提取点云子集，包括一些点云滤波算法也会经常得到点云的索引，然后根据这些点云索引来提取点云子集，下面代码示例了如何利用索引向量来构建点云索引并提取点云子集。

/*====================================================================== * Author : Haiming Zhang * Email : zhanghm_1995@qq.com * Version :　2018年10月29日 * Copyright : * Descriptoin : * References : ======================================================================*/ #include <iostream> #include <vector> #include <pcl/io/pcd_io.h> #include <pcl/point_types.h> #include <pcl/ModelCoefficients.h> #include <pcl/filters/extract_indices.h> using std::cout; using std::endl; int main() { pcl::PointCloud<pcl::PointXYZ>::Ptr cloud(new pcl::PointCloud<pcl::PointXYZ>); pcl::PointCloud<pcl::PointXYZ>::Ptr cloud_p(new pcl::PointCloud<pcl::PointXYZ>); cloud->width = 5; cloud->height = 1; cloud->points.resize (cloud->width * cloud->height); for (size_t i = 0; i < cloud->points.size (); ++i) { cloud->points[i].x = 1024 * rand () / (RAND_MAX + 1.0f); cloud->points[i].y = 1024 * rand () / (RAND_MAX + 1.0f); cloud->points[i].z = 1024 * rand () / (RAND_MAX + 1.0f); } std::cerr << "Cloud before extract: " << std::endl; for (size_t i = 0; i < cloud->points.size (); ++i) std::cerr << " " << cloud->points[i].x << " " << cloud->points[i].y << " " << cloud->points[i].z << std::endl; std::vector<int> index = {1,3,4};//提取1,3,4位置处点云 boost::shared_ptr<std::vector<int>> index_ptr = boost::make_shared<std::vector<int>>(index); // Create the filtering object pcl::ExtractIndices<pcl::PointXYZ> extract; // Extract the inliers extract.setInputCloud (cloud); extract.setIndices (index_ptr); extract.setNegative (false);//如果设为true,可以提取指定index之外的点云 extract.filter (*cloud_p); cout<<"----------------"<<endl; for (size_t i = 0; i < cloud_p->points.size (); ++i) std::cerr << " " << cloud_p->points[i].x << " " << cloud_p->points[i].y << " " << cloud_p->points[i].z << std::endl; }

输出结果：

Cloud before extract: 0.352222 -0.151883 -0.106395 -0.397406 -0.473106 0.292602 -0.731898 0.667105 0.441304 -0.734766 0.854581 -0.0361733 -0.4607 -0.277468 -0.916762 ---------------- -0.397406 -0.473106 0.292602 -0.734766 0.854581 -0.0361733 -0.4607 -0.277468 -0.916762

ExtractIndices类可以提供多种功能的点云子集提取，如果只是提取指定索引的点云组成一个新的点云，还可以用pcl::copyPointCloud函数：

std::vector<int > indexs = { 1, 2, 5 };//声明索引值 pcl::copyPointCloud(*cloud, indexs, *cloud_p);//将对应索引的点存储