pcl-常用小知识

计算时间

#include <pcl/console/time.h>

pcl::console::TicToc timer;
timer.tic();
//do something
std::cout << time.toc() << std::endl;

• 计算时间的单位为毫米。

查找点云的极值

#include <pcl/point_types.h>
#include <pcl/common/common.h>
#include <pcl/io/pcd_io.h>

pcl::PointCloud<pcl::PointXYZI>::Ptr cloud(new pcl::PointCloud<pcl::PointXYZI>);
pcl::io::loadPCDFile<pcl::PointXYZI>("file_dir", *cloud);

pcl::PointXYZI min_pt, max_pt;
pcl::getMinMax3D(*cloud, min_pt, max_pt);

拷贝点云

• 拷贝全部点云

#include <pcl/io/pcd_io.h>
#include <pcl/common/impl/io.hpp>
#include <pcl/point_types.h>
#include <pcl/point_cloud.h>
 
pcl::PointCloud<pcl::PointXYZI>::Ptr cloud(new pcl::PointCloud<pcl::PointXYZI>);
pcl::io::loadPCDFile<pcl::PointXYZI>("file_dir", *cloud);

pcl::PointCloud<pcl::PointXYZI>::Ptr cloudOut(new pcl::PointCloud<pcl::PointXYZI>);
pcl::copyPointCloud(*cloud, *cloudOut);

• 拷贝部分点云

#include <pcl/io/pcd_io.h>
#include <pcl/point_types.h>
#include <pcl/point_cloud.h>
 
pcl::PointCloud<pcl::PointXYZI>::Ptr cloud(new pcl::PointCloud<pcl::PointXYZI>);
pcl::PointCloud<pcl::PointXYZI>::Ptr cloudOut(new pcl::PointCloud<pcl::PointXYZI>);
pcl::io::loadPCDFile<pcl::PointXYZI>("file_dir", *cloud);

std::vector<int > indexs = { 1, 2, 5 };
pcl::copyPointCloud(*cloud, indexs, *cloudOut);

去除nan点

#include <pcl/point_cloud.h>
#include <pcl/point_types.h>
#include <pcl/filters/filter.h>
#include <pcl/io/pcd_io.h>

pcl::PointCloud<pcl::PointXYZI>::Ptr cloud(new pcl::PointCloud<pcl::PointXYZI>);
pcl::PointCloud<pcl::PointXYZI>::Ptr out_cloud(new pcl::PointCloud<pcl::PointXYZI>);
pcl::io::loadPCDFile<pcl::PointXYZI>("file_dir", *cloud);

std::vector<int> indices;
pcl::removeNaNFromPointCloud(*cloud, *out_cloud, indices);

点云坐标变换

#include <pcl/io/pcd_io.h>
#include <pcl/point_types.h>
#include <pcl/point_cloud.h>
#include <pcl/common/transforms.h>

pcl::PointCloud<pcl::PointXYZ>::Ptr cloud (new pcl::PointCloud<pcl::PointXYZ>);
pcl::PointCloud<pcl::PointXYZ>::Ptr trans_cloud (new pcl::PointCloud<pcl::PointXYZ>);
Eigen::Matrix4f transform_matrix = Eigen::Matrix4f::Identity();

pcl::transformPointCloud(*cloud,*trans_cloud,transform_matrix);

读取和写入pcd文件

Reading Point Cloud data from PCD files

#include <iostream>

#include <pcl/io/pcd_io.h>
#include <pcl/point_types.h>

int main (int argc, char** argv)
{
  pcl::PointCloud<pcl::PointXYZ>::Ptr cloud (new pcl::PointCloud<pcl::PointXYZ>);

  if (pcl::io::loadPCDFile<pcl::PointXYZ> ("test_pcd.pcd", *cloud) == -1) //* load the file
  {
    PCL_ERROR ("Couldn't read file test_pcd.pcd 
");
    return (-1);
  }

  return (0);
}

Writing Point Cloud data to PCD files

#include <iostream>
#include <pcl/io/pcd_io.h>
#include <pcl/point_types.h>

int main (int argc, char** argv)
{
  pcl::PointCloud<pcl::PointXYZ> cloud;

  // Fill in the cloud data
  cloud.width    = 5;
  cloud.height   = 1;
  cloud.is_dense = false;
  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);
  }

  pcl::io::savePCDFileASCII ("test_pcd.pcd", cloud);
  std::cerr << "Saved " << cloud.points.size () << " data points to test_pcd.pcd." << 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;

  return (0);
}

Concatenate the points of two Point Clouds

• If we are trying to concatenate points then the code below:

    cloud_c  = cloud_a;
    cloud_c += cloud_b;

creates cloud_c by concatenating the points of cloud_a and cloud_b together.

• Otherwise if we are attempting to concatenate fields then the code below:

    pcl::concatenateFields (cloud_a, n_cloud_b, p_n_cloud_c);

creates p_n_cloud_c by concatenating the fields of cloud_a and cloud_b together.