there is some issue for using the example codes of chapter 2

[LeonJung]

@lentinjose

Hi, long time no see since we met in ICRA 2017
how is it going?

I'm currently managing a external project which is learning more deeply about ROS and Vision Sensing.
To learn skills of those two keywords, we are looking through your book.

and we are doing some debugs of what is introduced in your book.

Now, since recent update comes, there were some issues in chapter2 example code.
I uploaded the modified one in my repo which forks your repo,
and I will do replacement of dynamixel package to the official one in late of this year.

If you are interested, or want PR, feel free to ask

Thanks

[christopherKorpela]

Hi-

I am trying to run the face_tracker_pkg but getting an opencv error. I am using Ubuntu 16.04 and ROS Kinetic (and opencv3). However, it appears that the facetracker node is using opencv2. Can you confirm? When I launch start_tracking, I get this error:

ERROR: Could not load classifier cascade
OpenCV Error: Assertion failed (!empty()) in detectMultiScale, file /tmp/binarydeb/ros-kinetic-opencv3-3.3.1/modules/objdetect/src/cascadedetect.cpp, line 1698
terminate called after throwing an instance of 'cv::Exception'

Thanks for any assistance.

[qboticslabs]

Hi @christopherKorpela

I think you have gone through the chapter also. You have to change the path of cascade file

https://github.com/qboticslabs/ros_robotics_projects/blob/master/chapter_2_codes/face_tracker_pkg/config/track.yaml

The error is because it is not getting the face.xml, because you need to change the username of the path. Then only it will work

[okeonwuka]

Yes.
Worked for me. By changing the "haar_file_face" parameter value in "track.yaml" from the original value to the actual path in my system that leads to "face.xml", i was able to get the code to work. Thanks..Good call!