Image Publisher and Subscriber in same node.

edit

I'm trying to get this code to work:

#include "ros/ros.h"
#include "std_msgs/String.h"
#include "image_transport/image_transport.h"
#include "opencv2/imgproc/imgproc.hpp"
#include "opencv2/highgui/highgui.hpp"
#include "cv_bridge/cv_bridge.h"
#include "image_geometry/pinhole_camera_model.h"

#include <sstream>

class GetRays{

private:

  image_transport::Publisher  pub;
  image_transport::Subscriber sub;

public:

  GetRays(ros::NodeHandle &nh, image_transport::ImageTransport &it){
    pub = it.advertise("/blob_map",1);
    sub = it.subscribe("/saliency_map", 1, imageCallback);
  }

  void thresholdImage(const sensor_msgs::ImageConstPtr& msg, sensor_msgs::ImageConstPtr& out){
    cv::Mat mat = cv_bridge::toCvShare(msg, "bgr8")->image;
    cv::threshold(mat,mat,0,255,3);
    out = cv_bridge::CvImage(std_msgs::Header(), "bgr8", mat).toImageMsg();
  }

  void imageCallback(const sensor_msgs::ImageConstPtr& msg)
  {
    sensor_msgs::ImageConstPtr thresh;
    thresholdImage(msg,thresh);
    pub.publish(msg);
  }
};

int main(int argc, char **argv)
{
  ros::NodeHandle nh;
  image_transport::ImageTransport it(nh);
  ros::init(argc, argv, "get_ray");
  GetRays getRays(nh,it);
  ros::spin();

  return 0;
}

But for some reason it keeps complaining that I'm not passing the right attributes to the it.subscribe("/saliency_map", 1, imageCallback) constructor:

/disk/users/lesi/Saliency/catkin_ws/src/saliency/src/get_rays.cpp: In constructor 'GetRays::GetRays(ros::NodeHandle&, image_transport::ImageTransport&)':
/disk/users/lesi/Saliency/catkin_ws/src/saliency/src/get_rays.cpp:22:57: error: no matching function for call to 'image_transport::ImageTransport::subscribe(const char [14], int, <unresolved overloaded function type>)'
     sub = it.subscribe("/saliency_map", 1, imageCallback);
                                                         ^
/disk/users/lesi/Saliency/catkin_ws/src/saliency/src/get_rays.cpp:22:57: note: candidates are:
In file included from /disk/users/lesi/Saliency/catkin_ws/src/saliency/src/get_rays.cpp:3:0:
/opt/ros/indigo/include/image_transport/image_transport.h:74:14: note: image_transport::Subscriber image_transport::ImageTransport::subscribe(const string&, uint32_t, const boost::function<void(const boost::shared_ptr<const sensor_msgs::Image_<std::allocator<void> > >&)>&, const VoidPtr&, const image_transport::TransportHints&)
   Subscriber subscribe(const std::string& base_topic, uint32_t queue_size,
              ^
/opt/ros/indigo/include/image_transport/image_transport.h:74:14: note:   no known conversion for argument 3 from '<unresolved overloaded function type>' to 'const boost::function<void(const boost::shared_ptr<const sensor_msgs::Image_<std::allocator<void> > >&)>&'
/opt/ros/indigo/include/image_transport/image_transport.h:82:14: note: image_transport::Subscriber image_transport::ImageTransport::subscribe(const string&, uint32_t, void (*)(const ImageConstPtr&), const image_transport::TransportHints&)
   Subscriber subscribe(const std::string& base_topic, uint32_t queue_size,
              ^
/opt/ros/indigo/include/image_transport/image_transport.h:82:14: note:   no known conversion for argument 3 from '<unresolved overloaded function type>' to 'void (*)(const ImageConstPtr&) {aka void (*)(const boost::shared_ptr<const sensor_msgs::Image_<std::allocator<void> > >&)}'
/opt/ros/indigo/include/image_transport/image_transport.h:95:14: note: template<class T> image_transport::Subscriber image_transport::ImageTransport::subscribe(const string&, uint32_t, void (T::*)(const ImageConstPtr&), T*, const image_transport::TransportHints&)
   Subscriber subscribe(const std::string& base_topic, uint32_t queue_size,
              ^
/opt/ros/indigo/include/image_transport/image_transport.h:95:14: note:   template argument deduction/substitution failed:
/disk/users/lesi/Saliency/catkin_ws/src/saliency/src/get_rays.cpp:22:57: note:   candidate expects 5 arguments, 3 provided
     sub = it.subscribe("/saliency_map", 1, imageCallback);
                                                         ^
In file included from /disk/users/lesi/Saliency/catkin_ws/src/saliency/src/get_rays.cpp:3:0:
/opt/ros/indigo/include/image_transport/image_transport.h:106:14: note ...