pcl::PointCloud<pcl::PointXYZ>::Ptr cloud;
cloud = pcl::PointCloud<pcl::PointXYZ>::Ptr(new pcl::PointCloud<pcl::PointXYZ>);
std::string szPath = "C:\\Users\\BZL\\Desktop\\rs1.pcd";
pcl::io::loadPCDFile<pcl::PointXYZ>(szPath, *cloud);
pcl::PointXYZ minPt, maxPt;
pcl::getMinMax3D(*cloud, minPt, maxPt);
std::cout << "Max x: " << maxPt.x << std::endl;
std::cout << "Max y: " << maxPt.y << std::endl;
std::cout << "Max z: " << maxPt.z << std::endl;
std::cout << "Min x: " << minPt.x << std::endl;
std::cout << "Min y: " << minPt.y << std::endl;
std::cout << "Min z: " << minPt.z << std::endl;