visp_tracker (tracker_viewer) doesn't work with klt

[ghanimmukhtar]

Hi there,

So I was testing the visp_tracker, when I use the default method (mbt) everything work, but when I pass through the launch file the parameter tracker_type as klt as follows:

 <node pkg="nodelet" type="nodelet" name="visp_tracker_client" output="screen"
        args="load visp_tracker/TrackerClient $(arg manager)">
    <param name="model_path" value="package://visp_tracker/models" />
    <param name="tracker_type" value="klt" />
    <param name="model_name" value="laas-box" />

    <!-- Load recommended settings for tracking initialization. They
      will be automatically forwarded to the tracking node if the
      initialization succeed. -->
    <rosparam file="$(find visp_tracker)/models/laas-box/tracker.yaml" />
  </node>

The node get stuck in the waitForImage() method with the periodic message:

waiting for a rectified image...

Any idea why? A quick look to the code shows that in both cases the image_subscriber is subscribing the same topic, so I don't really see why this is happening?? Thanks in advance for your feedback Cheers!

[fspindle]

It means maybe that the tracker doesn't have enough features (keypoints from klt). Try to reduce the value of the klt > quality parameter to get more features (has to be done in the xml file).

I recommend to rather use mbt or mbt+klt instead of just klt

[ghanimmukhtar]

@fspindle Thanx for your reply, so now the klt is working, I am trying with klt ->quality = 0.015 and it starts to work. I will try to tune further and see how it goes, sadly I don't know exactly the the meaning of this parameter cause it is not explained in visp tutorial so I guess I will do it by try/error

[fspindle]

Quality parameter meaning is described here.

[ghanimmukhtar]

So I did the catkin_make with the release flag for visp, visp_bridge and visp_tracker, and I put the klt > quality parameters with 0.001 and as you can see in this video, the first part is working well, then when I define the object and try to initialize the tracker it actually doesn't work still waiting for rectified image!! any ideas why the second part isn't working? I suspected that in the launch file I need to pass the parameter tracker_type as klt but it didn't work also. Sorry for the confusion, yesterday I thought it was working but actually I only checked the first part without initializing the tracker ;(

[ghanimmukhtar]

Actually it worked now I had to add the parameter tracker_type to nodelet_manager, tracker, tracker_client besides the tracker_viewer, my bad :)