点云TXT与PCD格式之间的转换

开发环境为win10+vstudio2019。

注：.txt形式的点云文件没有header，存储的全是xyz数据。如下图：

这个点云数据中不仅包含有x、y、z的位置信息，还包含其他的位置信息，因此我们只需要提取前三列的信息，并忽略前两行。提取后的数据如下图：

 提取后的点云并完成可视化，可视化效果如下图：

源码如下：
extrat_txt.hpp

#include <iostream>
#include <vector>
#include <iomanip>
#include <fstream>
#include <sstream>

using namespace std;

class ExtraTXT
{
public:
	void processing(string a,string b)
	{
		//从txt文件中获取指定列的内容
		ifstream ifs;
		ifs.open(a, ios::in);
		if (!ifs.is_open())
		{
			cout << "打开文件失败！！！";
		}
		cout << "数据读取中" << endl;
		vector<double> x, y, z;
		vector<string> item;				
		string temp;						
		while (getline(ifs, temp))          
		{
			item.push_back(temp);
		}
		for (auto it = item.begin() + 2; it != item.end(); it++)
		{
			istringstream istr(*it);                 
			string str;
			int count = 0;							 
			while (istr >> str)                      
			{
				if (count == 0)
				{
					double r = atof(str.c_str());       
					x.push_back(r);
				}
				else if (count == 1)
				{
					double r = atof(str.c_str());
					y.push_back(r);
				}
				else if (count == 2)
				{
					double r = atof(str.c_str());
					z.push_back(r);
				}
				count++;
			}
		}
		cout << "数据读取完成，正在生成新的txt文件" << endl;
		ofstream ofs;
		ofs.open(b, std::ios::out | std::ios::app);
		for (int i = 0; i < x.size(); i++)
		{
			ofs << x[i] << " " << y[i] << " " << z[i] << endl;
		}
		ofs.close();
		cout << "新的txt生成完成" << endl;
	}
};

main.cpp:

#pragma warning(disable:4996)
#include "extrat_txt.hpp"
#include <pcl/io/pcd_io.h>
#include <pcl/point_types.h>
#include<pcl/visualization/cloud_viewer.h>
#include<boost/thread/thread.hpp>

using namespace std;
using namespace pcl;

typedef struct tagPOINT_3D
{
	double x;  //mm world coordinate x
	double y;  //mm world coordinate y
	double z;  //mm world coordinate z
	double r;
}POINT_WORLD;

int main()
{
	ExtraTXT extra_txt;
	extra_txt.processing("未处理的txt/6.txt", "处理过的txt/6.txt");
   
	//加载txt数据
	int number_Txt;
	FILE* fp_txt;
	tagPOINT_3D TxtPoint;
	vector<tagPOINT_3D> m_vTxtPoints;
	fp_txt = fopen("处理过的txt/6.txt", "r");//这个地方填文件的位置
	cout << "txt正在转换为pcd" << endl;
	if (fp_txt)
	{
		while (fscanf(fp_txt, "%lf %lf %lf", &TxtPoint.x, &TxtPoint.y, &TxtPoint.z) != EOF)
		{
			m_vTxtPoints.push_back(TxtPoint);
		}
	}
	else
		cout << "txt数据加载失败！" << endl;
	number_Txt = m_vTxtPoints.size();
	pcl::PointCloud<pcl::PointXYZ> cloud;

	// Fill in the cloud data
	cloud.width = number_Txt;
	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 = m_vTxtPoints[i].x;
		cloud.points[i].y = m_vTxtPoints[i].y;
		cloud.points[i].z = m_vTxtPoints[i].z;
	}
	pcl::io::savePCDFileASCII("pcd/6.pcd", cloud);//这个地方填输出的路径
	std::cerr << "Saved " << cloud.points.size() << " data points to txt2pcd.pcd." << std::endl;
	cout << "txt转换pcd完成" << endl;

	//将pcl::PointCloud转换为pcl::PointCloud::Ptr类型
	pcl::PointCloud<pcl::PointXYZ>::Ptr cloudPointer(new pcl::PointCloud < pcl::PointXYZ>);
	cloudPointer = cloud.makeShared();

	boost::shared_ptr<pcl::visualization::PCLVisualizer> viewer(new pcl::visualization::PCLVisualizer("cloud viewer"));
	viewer->setBackgroundColor(0, 0, 0);
	viewer->addPointCloud<pcl::PointXYZ>(cloudPointer, "sample cloud");
	viewer->setPointCloudRenderingProperties(pcl::visualization::PCL_VISUALIZER_POINT_SIZE, 0.5, "sample cloud");
	viewer->addCoordinateSystem(1.0);
	viewer->initCameraParameters();
	while (!viewer->wasStopped()) {
		viewer->spinOnce(100);
		boost::this_thread::sleep(boost::posix_time::microseconds(100000));
	}

	system("pause");
	return 0;
}

需注意：

加了ptr的是指针类型，两者可以相互转换，在上边可视化的过程中需要先将pcl::PointCloud转换为pcl::PointCloud::Ptr，所以总结以下的转换代码
（1）pcl::PointCloud转换为pcl::PointCloud::Ptr

//将pcl::PointCloud转换为pcl::PointCloud::Ptr类型
	pcl::PointCloud<pcl::PointXYZ> cloud;
	pcl::PointCloud<pcl::PointXYZ>::Ptr cloudPointer(new pcl::PointCloud < pcl::PointXYZ>);
	cloudPointer = cloud.makeShared();

（2）pcl::PointCloud::Ptr转换为pcl::PointCloud

pcl::PointCloud<pcl::PointXYZ> cloud;
pcl::PointCloud<pcl::PointXYZ>::Ptr cloudPointer(new pcl::PointCloud<pcl::PointXYZ>);
cloud=*cloudPointer;