[ros-users] A published image does not appear.

Hello,
I tried to write a small package to subscribe to stereo images of
bumblebee2 and publish them with my own name.
The source code of my source file, (which uses stereo_image_proc) is
attached.


I ran this package like this from the prompt:

shell$ roslaunch bumblebee2 Bumblebee2.launch

shell$ ROS_NAMESPACE=bumblebee2 rosrun stereo_image_proc stereo_image_proc

shell$ rosrun trial1 trial1

(from 'rostopic list -v' i can see the topic "/Yucong/left/image_rect" is
published).

However, after using ' rosrun image_view image_view
image:=/Yucong/left/image_rect '

I see only a window without an image in it.

How can I see the image? Any help would be appreciated, especially since I
am pretty new to the ROS environment.

Thanks,

--
Yucong Lin
Graduate student
School of Earth and Space Exploration
Arizona State University
PSH 470




--
Yucong Lin
Graduate student
School of Earth and Space Exploration
Arizona State University
PSH 470
#include <ros/ros.h>
#include <ros/names.h>

#include <sensor_msgs/Image.h>
#include <sensor_msgs/CameraInfo.h>
#include <stereo_msgs/DisparityImage.h>
#include <image_transport/image_transport.h>
#include <image_transport/subscriber_filter.h>
#include <message_filters/subscriber.h>
#include <message_filters/time_synchronizer.h>

class MyTrialNode
{
private:
 ros::NodeHandle nh_;
 image_transport::ImageTransport it_;
// Subscriptions
 image_transport::SubscriberFilter image_sub_l_, image_sub_r_;
 image_transport::SubscriberFilter sub_rect_l_, sub_rect_r_;
 message_filters::Subscriber<stereo_msgs::DisparityImage> sub_disparity_;
 message_filters::Subscriber<sensor_msgs::CameraInfo> info_sub_l_, info_sub_r_;
 message_filters::TimeSynchronizer<sensor_msgs::Image, sensor_msgs::CameraInfo, 
                    sensor_msgs::Image, sensor_msgs::CameraInfo> sync_;
  int subscriber_count_;

// Publications
std::string left_ns_, right_ns_, yucong_left_ns_ , yucong_right_ns_ ;
image_transport::Publisher pub_rect_l_;
image_transport::Publisher pub_rect_r_;
ros::Publisher pub_disparity_;
//image_transport::CameraPublisher left_image_pub_;
//image_transport::CameraPublisher right_image_pub_;

int left_received_, right_received_, both_received_;

public:

 MyTrialNode() : it_(nh_), sync_(3),
      subscriber_count_(0),
      left_received_(0), right_received_(0), both_received_(0)
{   
    left_ns_ = nh_.resolveName("bumblebee2/left");
    right_ns_ = nh_.resolveName("bumblebee2/right");
    yucong_left_ns_ = nh_.resolveName("Yucong/left");
    yucong_right_ns_ = nh_.resolveName("Yucong/right");    

    //image_sub_l_.subscribe(it_, left_ns_   + "/image_raw", 1);
    //image_sub_r_.subscribe(it_, right_ns_  + "/image_raw", 1);
    info_sub_l_.subscribe(nh_, left_ns_  + "/camera_info", 1); 
    info_sub_r_.subscribe(nh_, right_ns_  + "/camera_info", 1);
    sub_rect_l_.subscribe(it_,  left_ns_ +"/image_rect",1);
    sub_rect_r_.subscribe(it_,  right_ns_ +"/image_rect",1);
    sub_disparity_.subscribe(nh_, "bumblebee2/disparity",1); 

    image_transport::SubscriberStatusCallback img_connect    = boost::bind(&MyTrialNode::connectCb, this);
    image_transport::SubscriberStatusCallback img_disconnect = boost::bind(&MyTrialNode::disconnectCb, this);

    pub_rect_l_       = it_.advertise(yucong_left_ns_+"/image_rect", 1, img_connect, img_disconnect);
    pub_rect_r_       = it_.advertise(yucong_right_ns_+"/image_rect", 1, img_connect, img_disconnect);

    ros::SubscriberStatusCallback msg_connect    = boost::bind(&MyTrialNode::connectCb, this);
    ros::SubscriberStatusCallback msg_disconnect = boost::bind(&MyTrialNode::disconnectCb, this);
    pub_disparity_ = nh_.advertise<stereo_msgs::DisparityImage>("Yucong/disparity", 1, msg_connect, msg_disconnect);
    sync_.connectInput(image_sub_l_, info_sub_l_, image_sub_r_, info_sub_r_);
  }  
    void connectCb()
  {
    if (subscriber_count_++ == 0) {
      ROS_DEBUG("[trial1] Subscribing to camera topics");
      /// @todo Make left and right subscriptions independent. Not easily possible with current synch tools.
      image_sub_l_.subscribe(it_, left_ns_ + "/image_raw", 1);
      image_sub_r_.subscribe(it_, right_ns_ + "/image_raw", 1);
      info_sub_l_.subscribe(nh_, left_ns_  + "/camera_info", 1); 
      info_sub_r_.subscribe(nh_, right_ns_  + "/camera_info", 1);
      sub_rect_l_.subscribe(it_,  left_ns_ +"/image_rect",1);
      sub_rect_r_.subscribe(it_,  right_ns_ +"/image_rect",1);
      sub_disparity_.subscribe(nh_, "bumblebee2/disparity",1); 
    }
  }

  void disconnectCb()
  {
    subscriber_count_--;
    if (subscriber_count_ == 0) {
      ROS_DEBUG("[trial1] Unsubscribing from camera topics");
      image_sub_l_ .unsubscribe();
      image_sub_r_ .unsubscribe();
      info_sub_l_ .unsubscribe();
      sub_rect_l_ .unsubscribe();
      info_sub_r_ .unsubscribe();
      sub_rect_r_ .unsubscribe();
      sub_disparity_ .unsubscribe();    
    }
  }

};

int main(int argc, char **argv)
{
ros::init(argc, argv, "trial1", ros::init_options::AnonymousName);
MyTrialNode my_node;
ros::spin();
return 0;
}