Yianni's profile - activity

@Chaos Nice one! Thanks!

@Chaos This might be of general interest. Do you have it anywhere in a public repository?

@Chaos Glad it worked :). Out of curiosity do you save as raw format the images or in some other format such as jpg/png?

@Chaos Although it is not ideal to put not cleaned up code, I updated my answer with my complete file that runs fine, for me at least :). Feel free to use it. Make sure you read the bold text as you need to change a couple of variables.

Hi @Chaos Please use ATtags otherwise it was fluke I saw this comment. Does the "original/unmodified" openni2_tracker run fine? roslaunch openni2_tracker tracker.launch Bear in mind that the above is a snippet rather than the complete file. If you need the complete file I can post it.

@ahendrix @jarvisschultz Thanks. Yes, makes sense as there would be I guess nasty security loopholes then. Unfortunately, it is not a memory issue but rather trying to get openni2_launch with openni2_tracker to work together, only one can open the xtion with the other getting the device descriptor.

Is it possible to pass an object pointer as a ROS message? Below a MWE, that doesn't even get to compile with error message:

talker.cpp:20:12: error: invalid conversion from ‘Foo*’ to ‘std_msgs::UInt64_<std::allocator<void> >::_data_type {aka long unsigned int}’ [-fpermissive]
msg.data = &foo;
         ^

MWE:

#include <iostream>
#include "ros/ros.h"
#include "std_msgs/UInt64.h"

class Foo
{
   public:
      int count;
};

int main(int argc, char **argv)
{
  ros::init(argc, argv, "talker");
  ros::NodeHandle n;
  ros::Publisher chatter_pub = n.advertise<std_msgs::UInt64>("chatter", 1000);
  ros::Rate loop_rate(10);
  Foo foo;
  foo.count = 0;
  std_msgs::UInt64 msg;
  msg.data = &foo;
  while (ros::ok())
  {
    chatter_pub.publish(msg);
    ros::spinOnce();
    loop_rate.sleep();
    ++foo.count;
  }
  return 0;
}

Might be a silly question give that the pointer is of the object type pointer, but all I need to do is pass the integer hex memory address to another node (and hopefully create a same object pointer that points to the same address). Possibly, a dangerous thing to do but it will suffice. Any help appreciated.

Same issue here. The question is whether and how do you pass this pointer as a ROS message?

Hello,

Is there a ropsy scheduler for calling a function after a period of time (or periodically calling it every n secs). The python sched module is kind of misbehaving, I guess it conflicts with ros based on the following example using the ps joystick with the PR2:

#!/usr/bin/env python
import roslib; roslib.load_manifest('d3')
import rospy
import sched, time
from sensor_msgs.msg import Joy

class Joystick(object):
    def __init__(self, topic_name='/joy'):
        self.topic_name = topic_name
        self.buttons_names = {'l1':10, 'l2':8}
        self.sub = rospy.Subscriber(topic_name, Joy, self.cb)
        self.blocked = False
        self.sched = sched.scheduler(time.time, time.sleep)
        print '>>> press L1 button'

    def cb(self, data):
        print '>> in callback:', data.buttons[self.buttons_names['l1']], data.buttons[self.buttons_names['l2']]
        if not self.blocked:
            self.foo(data)

    def foo(self, data):
        print '>> in foo:', data.buttons[self.buttons_names['l1']], data.buttons[self.buttons_names['l2']]
        if data.buttons[self.buttons_names['l1']]:
            self.blocked = True
            rospy.loginfo('%d', data.buttons[self.buttons_names['l1']])
            rospy.loginfo('L1 pressed')
            self.sched.enter(1, 1, self.bar, ())
        self.sched.run()

    def bar(self):
        rospy.loginfo('resuming control')
        self.blocked = False

if __name__=='__main__':
    rospy.init_node('foo', anonymous=False)
    joy = Joystick()
    rospy.spin()

Thanks!

Hi,

I am trying to compile my package but I am getting the following error:

/usr/bin/ld: cannot find -lgripper_click_ui
collect2: ld returned 1 exit status

In my manifest I have the following two dependencies which possibly give me the hard time but it should be including the missing library:

<depend package="pr2_gripper_click"/>
<depend package="pr2_pick_and_place_demos"/>

This error occurs when I run make or rosmake. I am using diamondback.

Any clues?

Many thanks.

Hi, it might be simple so apologies for this post... but I can't find the solution.

I would like to get the sensor_msgs::Image::Ptr of a sensor_msgs::Image. Basically I would like to do the conversion of a sensor_msgs::Image to an cv IplImage using:

sensor_msgs::CvBridge bridge_;
bridge_.imgMsgToCv

which takes actually

sensor_msgs::Image::ConstPtr

as found in CvBridge.h (diamondback)

IplImage* imgMsgToCv(sensor_msgs::Image::ConstPtr rosimg, std::string desired_encoding = "passthrough")

and hence my failing.

Basically, I would like to do the following:

sensor_msgs::CvBridge bridge_;
sensor_msgs::Image image_msg = <to a sensor_msgs::Image>;
sensor_msgs::Image::Ptr rosimg;
missing statement??
bridge_.imgMsgToCv(rosimg, "bgr8");

Many thanks.

Hi,

I am trying to publish an array of images. Looking at ros wiki I couldn't find something relevant... I am attaching below my code... The publishing of the array should be at the "try" clause. Any help or hints would be appreciated.

Thanks.

#include "boost/filesystem.hpp"
#include "sensor_msgs/Image.h"
#include "image_transport/image_transport.h"
#include "cv_bridge/CvBridge.h"
#include "std_msgs/String.h"

#include <iostream>
#include <string>
#include <vector>
#include <opencv/cv.h>
#include <opencv/highgui.h>
#include <ros/ros.h>
#include <signal.h>

using namespace boost::filesystem;
using namespace std;

void ctrlc(int s)
{
    cout << "ctrl-c pressed" << endl;
    ros::shutdown();
    signal(SIGINT, SIG_DFL);
}

int main(int argc, char *argv[])
{
    ros::init(argc, argv, "Static_Image_Publisher");
    ros::NodeHandle n;
    image_transport::ImageTransport it_(n);
    sensor_msgs::CvBridge bridge_;
    image_transport::Publisher image_pub_;
    image_pub_ = it_.advertise("/camera_sim/image_raw", 1);
    int cvDelay = (argc == 2 ? atoi(argv[1]) : 500);
    string p(argc == 3 ? argv[2] : ".");
    vector<string> filenames;
    IplImage *img = NULL;
    vector<IplImage*> imgs;

    if (is_directory(p))
        for (directory_iterator itr(p); itr!=directory_iterator(); ++itr)
            if (is_regular_file(itr->status())) {
                string str(itr->path().file_string());
                filenames.push_back(str);
            }

    sort(filenames.begin(), filenames.end());
    signal(SIGINT, ctrlc);
    for(;;) {
        imgs.clear();
        for (vector<string>::iterator itr = filenames.begin(); itr != filenames.end(); ++itr) {
            img = cvLoadImage(itr->c_str());
            imgs.push_back(img);
        }
        try {
            cout << ".\n";
            // publishes one image at a time, how would I publish the array of images
            //image_pub_.publish(bridge_.cvToImgMsg(imgs[0], "bgr8"));
        } catch (sensor_msgs::CvBridgeException error) {
            ROS_ERROR("error");
        }
    }

    ros::spin();
    return 0;
}

Hi,

is there a python equivalent of fromROSMsg/toROSMsg (pcl stack)?

Thanks.

Hi,

I was looking at the source code of the NARF descriptor and I modified the tutorial example (narf_feature_extraction) to calculate all the time the NARF descriptors from a pointcloud coming from a kinect camera. I have noticed a couple of things:

1. Some times there are more descriptors than keypoints... I see that the size of the keypoints is taken from keypoint_indices2 and the descriptors are held in narf_descriptors. Is it correct that there are more descriptors than keypoints computed?

2. I noticed the descritptor values for a pointcloud of a mug for example are around between -0.3 and 0.3, and with any object or the complete pointcould the values are between -0.5 and 0.5... If someone has experience and know the range of values it would be great... as I had a look on the paper (Steder et al., 2011) but I couldn't find out something specifically about it...

Many Thanks,
Yianni