LASlib 读写点云

一、参考链接

1、LASlib / LAStools
2、LASlib库将PCL库点云类型数据转换为las格式保存
3、.las数据转.pcd并显示
las格式详解：
[1]孙爱怡,王健.LAS格式的解析与转换[J].全球定位系统,2016,41(02):115-117+124.

二、代码

#include "lasreader.hpp"
#include "laswriter.hpp"
#include"LasReadWrite.h"


/* read las */
void LasLib::ReadLas(const std::string& LasPath, pcl::PointCloud<PointT>::Ptr& Read_cloud)
{
	LASreadOpener lasReadOpener;
	lasReadOpener.set_file_name(LasPath.data());
	//lasReadOpener.set_file_name(sLasPath.c_str());
	LASreader* lasReader = lasReadOpener.open(false);

#pragma region Las information
	int majorVersion = lasReader->header.version_major;         // las文件的版本号
	int minorVersion = lasReader->header.version_minor;
	int pointDataFormat = lasReader->header.point_data_format;  // Lidar点的记录格式
	int pointAmount = lasReader->header.number_of_point_records;// Lidar点的个数
	double maxX = lasReader->header.max_x;                      // x坐标的最大值
	double minX = lasReader->header.min_x;                      // x坐标的最小值
	double maxY = lasReader->header.max_y;                      // y坐标的最大值
	double minY = lasReader->header.min_y;                      // y坐标的最小值
	double maxZ = lasReader->header.max_z;                      // z坐标的最大值
	double minZ = lasReader->header.min_z;                      // z坐标的最小值
	double deltaX = maxX - minX;                                // x坐标的取值范围
	double deltaY = maxY - minY;                                // y坐标的取值范围
	double deltaZ = maxZ - minZ;                                // z坐标的取值范围
	double xOffset = lasReader->header.x_offset;                // X方向的偏移量
	double yOffset = lasReader->header.y_offset;                // Y方向的偏移量
	double zOffset = lasReader->header.z_offset;                // Z方向的偏移量
	double xScale = lasReader->header.x_scale_factor;           // X方向的比例尺因子
	double yScale = lasReader->header.y_scale_factor;           // Y方向的比例尺因子
	double zScale = lasReader->header.z_scale_factor;           // Z方向的比例尺因子
#pragma endregion

	int pNumber = 0;
	while (lasReader->read_point())
	{
		LASpoint& pointReader = lasReader->point;

		PointT p;
		p.x = pointReader.get_x()- xOffset;
		p.y = pointReader.get_y()- yOffset;
		p.z = pointReader.get_z()- zOffset;
		//p.r = pointReader.get_R();
		//p.g = pointReader.get_G();
		//p.b = pointReader.get_B();
		//p.intensity = pointReader.get_intensity();
		//p.pointSourceID = pointReader.get_point_source_ID();
		//p.GPStime = pointReader.get_gps_time();
		
		//p.classification = pointReader.get_classification();
		Read_cloud->points.push_back(p);
		pNumber++;

#pragma endregion
	}

	lasReader->close();
	delete lasReader;
	lasReader = nullptr;
}

/* write las */
void LasLib::WriteLas(const std::string& sResultPath, pcl::PointCloud<PointT>::Ptr& Write_cloud)
{

	LASwriteOpener lasWriterOpener;
	lasWriterOpener.set_file_name(sResultPath.data());

	// init header
	LASheader lasHeader;
	lasHeader.x_scale_factor = 0.0001;
	lasHeader.y_scale_factor = 0.0001;
	lasHeader.z_scale_factor = 0.0001;
	lasHeader.x_offset = (int)Write_cloud->points[0].x;
	lasHeader.y_offset = (int)Write_cloud->points[0].y;
	lasHeader.z_offset = (int)Write_cloud->points[0].z;
	lasHeader.point_data_format = 3;
	lasHeader.point_data_record_length = 34; // 变长记录
	//lasHeader.number_of_point_records = vPoints.size();

	// open laswriter
	LASwriter* lasWriter = lasWriterOpener.open(&lasHeader);

	// init point
	LASpoint lasPoint;
	lasPoint.init(&lasHeader, lasHeader.point_data_format, lasHeader.point_data_record_length, 0);

	// write points
	double minX = DBL_MAX, minY = DBL_MAX, minZ = DBL_MAX;
	double maxX = -DBL_MAX, maxY = -DBL_MAX, maxZ = -DBL_MAX;
	for (int i = 0; i < Write_cloud->points.size(); i++)
	{
		// populate the point
		lasPoint.set_x(Write_cloud->points[i].x);
		lasPoint.set_y(Write_cloud->points[i].y);
		lasPoint.set_z(Write_cloud->points[i].z);
		//lasPoint.set_R(write_cloud->points[i].r);
		//lasPoint.set_G(write_cloud->points[i].g);
		//lasPoint.set_B(write_cloud->points[i].b);

		//lasPoint.set_intensity(write_cloud->points[i].intensity);
		//lasPoint.set_point_source_ID(write_cloud->points[i].pointSourceID);
		//lasPoint.set_gps_time(write_cloud->points[i].GPStime);
		//lasPoint.set_classification(write_cloud->points[i].classification);


		// write the point
		lasWriter->write_point(&lasPoint);

		// add it to the inventory
		lasWriter->update_inventory(&lasPoint);

		//range
		double x = Write_cloud->points[i].x;
		double y = Write_cloud->points[i].y;
		double z = Write_cloud->points[i].z;
		if (x < minX) minX = x;
		if (x > maxX) maxX = x;
		if (y < minY) minY = y;
		if (y > maxY) maxY = y;
		if (z < minZ) minZ = z;
		if (z > maxZ) maxZ = z;
	}

	// update the boundary
	lasHeader.set_bounding_box(minX, minY, minZ, maxX, maxY, maxZ);

	// update the header
	lasWriter->update_header(&lasHeader, true);

	// close the writer
	lasWriter->close();
	delete lasWriter;
	lasWriter = nullptr;
}