#include <ros/ros.h>
#include <image_transport/image_transport.h>
#include <cv_bridge/cv_bridge.h>
#include <sensor_msgs/image_encodings.h>
#include <opencv2/imgproc/imgproc.hpp>
#include <opencv2/highgui/highgui.hpp>
  
include <image_transport image_transport.h="">
 
include <cv_bridge cv_bridge.h="">
 
include <sensor_msgs image_encodings.h="">
 
include <opencv2 imgproc="" imgproc.hpp="">
 
include <opencv2 highgui="" highgui.hpp="">
 
void callback(const sensor_msgs::ImageConstPtr& msg) {  
 cv_bridge::CvImagePtr cvImagePtr; try {

     cvImagePtr = cv_bridge::toCvCopy(msg);

     //cv::Mat &mat = cvImagePtr->image;

     cv::imshow("windowName", cvImagePtr->image);

     cv::destroyWindow("windowName");

      } 

 catch (cv_bridge::Exception &e) {

    ROS_ERROR("cv_bridge exception:  %s", e.what());
 }
 
}
 
}
int main(int argc, char **argv) {{
  
ros::init(argc, argv, "nodeName");  
cv::namedWindow("windowName");cv::namedWindow("windowName");

ros::NodeHandle nh;

image_transport::ImageTransport it(nh);  
ros::NodeHandle nh;
 
image_transport::ImageTransport it(nh); 
 
image_transport::Subscriber sub = it.subscribe("/ardrone/image_raw", 1, callback);  
ros::spin();ros::spin();
  
}}