ros中message_filter类常用的使用方法

 1     #include <message_filters/subscriber.h>
 2     #include <message_filters/time_synchronizer.h>
 3     #include <sensor_msgs/Image.h>
 4     #include <sensor_msgs/CameraInfo.h>
 5      
 6     using namespace sensor_msgs;
 7     using namespace message_filters;
 8      
 9     void callback(const ImageConstPtr& image, const CameraInfoConstPtr& cam_info)
10     {
11       // Solve all of perception here...
12     }
13      
14     int main(int argc, char** argv)
15     {
16       ros::init(argc, argv, "vision_node");
17      
18       ros::NodeHandle nh;
19      
20       message_filters::Subscriber<Image> image_sub(nh, "image", 1);
21       message_filters::Subscriber<CameraInfo> info_sub(nh, "camera_info", 1);
22       TimeSynchronizer<Image, CameraInfo> sync(image_sub, info_sub, 10);
23       sync.registerCallback(boost::bind(&callback, _1, _2));
24      
25       ros::spin();
26      
27       return 0;
28     }

1     message_filters::Subscriber<std_msgs::String> sub(nh, "my_topic", 1);
2     message_filters::TimeSequencer<std_msgs::String> seq(sub, ros::Duration(0.1), ros::Duration(0.01), 10);
3     seq.registerCallback(myCallback);

 1 tf_ = new TransformListenerWrapper();
 2 message_filters::Subscriber<sensor_msgs::LaserScan>* laser_scan_sub_;
 3 tf::MessageFilter<sensor_msgs::LaserScan>* laser_scan_filter_;
 4  
 5 laser_scan_sub_ = new message_filters::Subscriber<sensor_msgs::LaserScan>(nh_, scan_topic_, 100);
 6 laser_scan_filter_ = new tf::MessageFilter<sensor_msgs::LaserScan>(*laser_scan_sub_, 
 7                                                         *tf_, 
 8                                                         odom_frame_id_, 
 9                                                         100);
10  
11 laser_scan_filter_->registerCallback(boost::bind(&AmclNode::laserReceived, this, _1));
12  
13 void AmclNode::laserReceived(const sensor_msgs::LaserScanConstPtr& laser_scan){
14     this->tf_->transformPose(base_frame_id_, ident, laser_pose);//这个函数的意思是，ident在base_frame_id下的表示为laser_pose
15 }

 1 #include "ros/ros.h"
 2 #include "tf/transform_listener.h"
 3 #include "tf/message_filter.h"
 4 #include "message_filters/subscriber.h"
 5 
 6 class PoseDrawer
 7 {
 8 public:
 9   PoseDrawer() : tf_(),  target_frame_("turtle1")
10   {
11     point_sub_.subscribe(n_, "turtle_point_stamped", 10);
12     tf_filter_ = new tf::MessageFilter<geometry_msgs::PointStamped>(point_sub_, tf_, target_frame_, 10);
13     tf_filter_->registerCallback( boost::bind(&PoseDrawer::msgCallback, this, _1) );
14   } ;
15 
16 private:
17   message_filters::Subscriber<geometry_msgs::PointStamped> point_sub_;
18   tf::TransformListener tf_;
19   tf::MessageFilter<geometry_msgs::PointStamped> * tf_filter_;
20   ros::NodeHandle n_;
21   std::string target_frame_;
22 
23   //  Callback to register with tf::MessageFilter to be called when transforms are available
24   void msgCallback(const boost::shared_ptr<const geometry_msgs::PointStamped>& point_ptr) 
25   {
26     geometry_msgs::PointStamped point_out;
27     try 
28     {
29       tf_.transformPoint(target_frame_, *point_ptr, point_out);
30       
31       printf("point of turtle 3 in frame of turtle 1 Position(x:%f y:%f z:%f)\n", 
32              point_out.point.x,
33              point_out.point.y,
34              point_out.point.z);
35     }
36     catch (tf::TransformException &ex) 
37     {
38       printf ("Failure %s\n", ex.what()); //Print exception which was caught
39     }
40   };
41 
42 };
43 
44 
45 int main(int argc, char ** argv)
46 {
47   ros::init(argc, argv, "pose_drawer"); //Init ROS
48   PoseDrawer pd; //Construct class
49   ros::spin(); // Run until interupted 
50 };