#include<pcl/point_cloud.h>
#include<pcl/point_types.h>
#include<pcl/visualization/pcl_visualizer.h> //cout endl

#include <pcl/common/time.h>

typedef pcl::PointXYZ PointT;

//定义测量在代码块中花费的时间的方法

int main()
{
    pcl::StopWatch stopWatch;
        //......
        //运行的代码块
        //......
    double milliseconds = stopWatch.getTime();

    system("pause");
    return 0;
}

参考文章：
http://pointclouds.org/documentation/common_2time_8h.html
http://pointclouds.org/documentation/common_2time_8h_source.html