ros 下面 nodelet 和 message filter 的使用

#include <pluginlib/class_list_macros.h>
#include <ros/ros.h>
#include "../include/fuse_point_multi_camera/fuse_point_multi_camera.h"

using namespace cv;
using namespace std;
using namespace sensor_msgs;
using namespace Eigen;

namespace point_cloud_color {
    typedef pcl::PointCloud<pcl::PointXYZRGB> PointCloudXYZRGB;
    ros::Publisher pcl_pub;
    image_transport::Publisher pub;
    using namespace cv;
    class Color_Nodelet : public nodelet::Nodelet {

  //  private:

        ros::NodeHandle nh_;
        image_transport::ImageTransport it;//(nh_);
        message_filters::Subscriber<PointCloud2> pc_sub;
        message_filters::Subscriber<CameraInfo> cinfo_sub;
        message_filters::Subscriber<Image> image_sub;
        typedef message_filters::sync_policies::ApproximateTime<PointCloud2, CameraInfo, Image> SyncPolicy;

        typedef message_filters::Synchronizer<SyncPolicy> sync;//(SyncPolicy(10), pc_sub, cinfo_sub, image_sub);

        boost::shared_ptr<sync> sync_;
    public:
       Color_Nodelet()
        :it(nh_){
             ;
        }
        ~Color_Nodelet(){};

        void callback(const PointCloud2::ConstPtr& pcl_msg, const CameraInfoConstPtr& cinfo_msg, const ImageConstPtr& image_msg){
            ROS_INFO("Nodelet ................................!");

            std::cout<<"received image!!!"<<std::endl;
            ROS_INFO("Projecting poincloud to the image %ld", pcl_msg->header.stamp.toNSec()-image_msg->header.stamp.toNSec());
        }


        void onInit() {


            NODELET_DEBUG("Initializing nodelet...");
            ROS_INFO("Nodelet is Ok for test!!");


            pc_sub.subscribe(nh_, "/velodyne/velodyne_points", 1);

            cinfo_sub.subscribe(nh_, "/camera_17082034/camera_info", 1);
            image_sub.subscribe(nh_, "/camera_17082034/image_raw", 1);

            sync_.reset(new sync( SyncPolicy(10), pc_sub, cinfo_sub, image_sub));


            sync_->registerCallback(boost::bind(&Color_Nodelet::callback,this, _1, _2, _3));

        }

    };
}

PLUGINLIB_EXPORT_CLASS(point_cloud_color::Color_Nodelet, nodelet::Nodelet)