erivera1802's profile - activity

Then what should I modify? Because yes, my queue size is already 1

Than what should I modify? Because yes, my queue size is already 1

The problem is that I have already stopped using the rosbag, and began using a real environment, and I still get the del

Real time Image topic subscription Hi everyone, im trying to work on an object detector in ROS, using the deep learning

Use Tensorflow detection API in ROS Hi everyone, I would like to know if the Tensorflow Object detection API can already

I have not only used the accepted solution, but change the susbscriber type: subscriber_=it.subscribeCamera("/sensors/c

It was really funny, because a tried this solution at first, and it didnt work, but when I write the new node to show yo

Hi, Im trying to wrtie a node that subscribes to a image topic, however, after almost copying the ros tutorial, I keep getting an error. The relevant parts of my code are:

ros::NodeHandle nh;
image_transport::ImageTransport it(nh);
image_transport::Subscriber sub;
sub=it.subscribe("/sensors/camera/top/image_raw",1, Imtest::callbackSubscriber);

And my callback is:

void Imtest::callbackSubscriber(const sensor_msgs::ImageConstPtr& msg)

The error I get is:

/home/kal3-5/workspaces/my_first_ws/src/imtest_ros_tool/src/imtest/imtest.cpp:41:83: error: invalid use of non-static member function
     sub=it.subscribe("/sensors/camera/top/image_raw",1, Imtest::callbackSubscriber);

My version of ROS is Kinetic, Ubuntu 16.04

Create a subscriber to an Image topic Hi, Im trying to wrtie a node that subscribes to a image topic, however, after alm

Hi, im trying to adapt a Kalman filter cpp code to a node cpp in ROS, but in the very beginning, the initialization goes wrong, more precisly, when i try to set the matrices, this is the relevant part of the code.

int stateSize = 4;
int measSize = 2;
int contrSize = 0;
unsigned int type = CV_32F;
cv::KalmanFilter kf(stateSize, measSize, contrSize, type);
cv::Mat state(stateSize, 1, type);  // [x,y,v_x,v_y,w,h]
cv::Mat meas(measSize, 1, type);
setIdentity(kf.measurementMatrix);

The compiler shows me the next error:

error: expected constructor, destructor, or type conversion before ‘(’ token
setIdentity(kf.measurementMatrix);

I really have no idea what is happening, because those lines show no problem in the "pure" cpp code. Hope someone can help me, thanks.

EDIT 1:

#include <ros/ros.h>
#include <image_transport/image_transport.h>
#include <sensor_msgs/image_encodings.h>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/imgproc/imgproc.hpp>
#include <cv_bridge/cv_bridge.h>
#include <geometry_msgs/Twist.h>
#include <std_msgs/Empty.h>
#include <std_msgs/String.h>
#include <sstream>
#include <image_transport/image_transport.h>
#include <cv_bridge/cv_bridge.h>
#include <stdio.h>
#include <iostream>
#include <cmath>
#include "opencv2/core/core.hpp"
#include "opencv2/features2d/features2d.hpp"
#include "opencv2/nonfree/features2d.hpp"
#include "opencv2/nonfree/nonfree.hpp"
#include <ros/package.h>
#include "opencv2/calib3d/calib3d.hpp"
#include <geometry_msgs/Point.h>
#include <fstream>
#include <opencv2/video/video.hpp>
#include "opencv2/video/tracking.hpp"

Thanks! That was exactly what i needed.

Hey!, I would like to name some archives, which I create in a ROS node, with a string related to the actual date on which the node is called. I already have used Ros time, but I dont know what does this "absolute" time means. My code is:

ros::Time begin = ros::Time::now();
ROS_INFO("%d\n", begin.sec);

And the output is:

[ INFO] [1508853591.867555047, 1508853591.867143646]: 1508853591

My questions are, what does this "1508853591" means? And how could I get something like 24-10-2017-16:13 or like it?

Thanks!

How to read the actual date in ROS Hey!, I would like to name some archives, which I create in a ROS node, with a string

Hi there, I was trying to migrate a code that uses SURF from cpp to a kind of ROS cpp. But when i think that the compiler almost done it, it shows me an error after linking the executable. Here is my code:

#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 <stdio.h>
#include <iostream>
#include "opencv2/core/core.hpp"
#include "opencv2/features2d/features2d.hpp"
#include "opencv2/nonfree/features2d.hpp"
#include "opencv2/nonfree/nonfree.hpp"

using namespace cv;
using namespace std;
static const std::string OPENCV_WINDOW = "Image window";
class ImageConverter
{
  ros::NodeHandle nh_;
  image_transport::ImageTransport it_;
  image_transport::Subscriber image_sub_;
  image_transport::Publisher image_pub_;

public:
  ImageConverter()
    : it_(nh_)
  {
    // Subscribe to input video feed and publish output video feed
    image_sub_ = it_.subscribe("/ardrone/front/image_raw", 1, 
      &ImageConverter::imageCb, this);
    image_pub_ = it_.advertise("/image_converter/output_video", 1);

    namedWindow(OPENCV_WINDOW);
  }

  ~ImageConverter()
  {
    destroyWindow(OPENCV_WINDOW);
  }

  void imageCb(const sensor_msgs::ImageConstPtr& msg)
  {
    cv_bridge::CvImagePtr cv_ptr;
    try
    {
      cv_ptr = cv_bridge::toCvCopy(msg, sensor_msgs::image_encodings::BGR8);
    }
    catch (cv_bridge::Exception& e)
    {
      ROS_ERROR("cv_bridge exception: %s", e.what());
      return;
    }

    // Draw an example circle on the video stream

    Mat img_hsv;
    cvtColor(cv_ptr->image,img_hsv,CV_BGR2GRAY);
    // Update GUI Window
    cv::imshow(OPENCV_WINDOW, img_hsv);
    int minHessian = 400;
    SurfFeatureDetector detector( minHessian );
        waitKey(3);

    // Output modified video stream
    image_pub_.publish(cv_ptr->toImageMsg());
  }
};

int main(int argc, char** argv)
{
  ros::init(argc, argv, "image_converter");
  ImageConverter ic;
  ros::spin();
  return 0;
}

This is the problematic line:

SurfFeatureDetector detector( minHessian );

The error that I got is:

Linking CXX executable /home/edrone/catkin_ws/devel/lib/stream/stream_node
CMakeFiles/stream_node.dir/src/stream_node.cpp.o: In function `ImageConverter::imageCb(boost::shared_ptr<sensor_msgs::Image_<std::allocator<void> > const> const&)':
stream_node.cpp:(.text._ZN14ImageConverter7imageCbERKN5boost10shared_ptrIKN11sensor_msgs6Image_ISaIvEEEEE[_ZN14ImageConverter7imageCbERKN5boost10shared_ptrIKN11sensor_msgs6Image_ISaIvEEEEE]+0x134): undefined reference to `cv::SURF::SURF(double, int, int, bool, bool)'
CMakeFiles/stream_node.dir/src/stream_node.cpp.o: In function `cv::SURF::~SURF()':
stream_node.cpp:(.text._ZN2cv4SURFD1Ev[_ZN2cv4SURFD1Ev]+0xe): undefined reference to `vtable for cv::SURF'
stream_node.cpp:(.text._ZN2cv4SURFD1Ev[_ZN2cv4SURFD1Ev]+0x26): undefined reference to `vtable for cv::SURF'
stream_node.cpp:(.text._ZN2cv4SURFD1Ev[_ZN2cv4SURFD1Ev]+0x2e): undefined reference to `vtable for cv::SURF'
stream_node.cpp:(.text._ZN2cv4SURFD1Ev[_ZN2cv4SURFD1Ev]+0x3b): undefined reference to `VTT for cv::SURF'
collect2: error: ld returned 1 exit status
make[2]: *** [/home/edrone/catkin_ws/devel/lib/stream/stream_node] Error 1
make[1]: *** [stream/CMakeFiles/stream_node.dir/all] Error 2
make: *** [all] Error 2
Invoking "make -j8 -l8" failed

I haven't seen that kind of error ever, And I know what ist the line that is causing me trouble, but I dont know what to do.

I appreciate your help.

Why I have to run a node twice to make it work? Hi, I have just written a node that subscribes to a topic, however, the

Hi, Im trying to read the /ardrone/odometry topic, but it is showing me very large values of x and y position Just When it starts. Im am wondering if there is a way to reset the odometry topic so it shows me 0 for the positions on the beginning. Also, the time that it shows is very large, so it has been counting long ago.

Thanks

Hello, I need to use a SURF feature detector in ros. I succeded when I used it outside ROS, but when i try to make a code for a node in ROS, the compiler shows me this:

CMakeFiles/stream_node.dir/src/stream_node.cpp.o: In function    `ImageConverter::imageCb(boost::shared_ptr<sensor_msgs::Image_<std::allocator<void> > const> const&)':stream_node.cpp:  (.text._ZN14ImageConverter7imageCbERKN5boost10shared_ptrIKN11sensor_msgs6Image_ISaIvEEEEE[_ZN14ImageConverter7imageCbERKN5boost10shared_ptrIKN11sensor_msgs6Image_ISaIvEEEEE]+0x134): undefined reference to `cv::SURF::SURF(double, int, int, bool, bool)'
 CMakeFiles/stream_node.dir/src/stream_node.cpp.o: In function `cv::SURF::~SURF()':
 stream_node.cpp:(.text._ZN2cv4SURFD1Ev[_ZN2cv4SURFD1Ev]+0xe): undefined reference to `vtable for cv::SURF'
 stream_node.cpp:(.text._ZN2cv4SURFD1Ev[_ZN2cv4SURFD1Ev]+0x26): undefined reference to `vtable for cv::SURF'
 stream_node.cpp:(.text._ZN2cv4SURFD1Ev[_ZN2cv4SURFD1Ev]+0x2e): undefined reference to `vtable for cv::SURF'
 stream_node.cpp:(.text._ZN2cv4SURFD1Ev[_ZN2cv4SURFD1Ev]+0x3b): undefined reference to `VTT for cv::SURF'
 collect2: error: ld returned 1 exit status

I understand it is because SURF is ubicated in a nonfree library of opencv, then, my includes are:

#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 <stdio.h>
#include <iostream>
#include "opencv2/core/core.hpp"
#include "opencv2/features2d/features2d.hpp"
#include "opencv2/nonfree/features2d.hpp"
#include "opencv2/nonfree/nonfree.hpp"

However, It still doesnt work. Somebody knows what I have to do? Maybe editing the CMakeList.txt?

Thanks!

Hi there, I want to check two topics at the same time, but as the title says, they are different type and arent synchronized, so I think I cant use the message filter example in the ROS Wiki. Here is the relevant part of the code, where I subscribe only to the camera topic:

Inside the main:

image_transport::ImageTransport it(nh);
image_transport::Subscriber sub = it.subscribe("/ardrone/image_raw", 1, imageCallback);

Callback:

void imageCallback(const sensor_msgs::ImageConstPtr& msg)
{

I want to subscribe to /ardrone/image_raw and /ardrone/navdata topics. Image raw is type image transport and navdata is a custom type. Also, an acceptable option would be that the callback only response to the Navdata topic, but inside i could read the actual image in the image_raw topic, cause the navdata topic is faster as the camera topic

Thanks!

Hi, I was wondering if someone has used the Kalman filter of Opencv inside ROS. The "normal" Opencv program works perfectly, but when i use it inside ros (The same code), it throws me the following error:

‘KF’ does not name a type
 KF.transitionMatrix = *(Mat_<float>(4, 4) << 1,0,1,0,   0,1,0,1,  0,0,1,0,  0,0,0,1);

The relevant include is:

#include <opencv2/video/tracking.hpp>
#include <opencv2/video/video.hpp>

That is the same that I use in the normal Opencv code, but in ROS it doesnt work.

Thanks