Hi Marcus, I haven't thought through use cases very much but one application would be creating a library of human gestures and poses that the robot can learn to recognize. The only reason I created a Skeleton message type for my pi_tracker package is that I wanted to have access to the joint confidence values. Otherwise, I think the standard ROS tf/tfMessage type comes close. In the meantime, and just for fun, I have created a skeleton_markers package at: http://www.ros.org/wiki/skeleton_markers This allows the visualization of the tracked joints in RViz. There are two ways to run the package--two different Python scripts: one is used with pi_tracker and subscribes to the skeleton message topic. The other uses just the transforms published by the openni_tracker package. See the Wiki page for details. Here is a short video of the result: http://www.youtube.com/watch?v=nTRi_kIgGW0 --patrick On 03/26/2011 03:27 PM, Marcus Liebhardt wrote: > Hi there! > > That indeed looks like a tree to me. > I would be interested in the use cases you have in mind for these > skeleton messages. > What information would you like to gather in those messages? > Poses of the tracked frames, interconnections of each frame, also > distances between the connected frames? > > I don't have deep knowledge about the processing of the KInect or the > openni_tracker. I'm currently just using the transforms. But I think > there are simplifications made for some frames, which could be useful > to take into account. For example, I think the neck is always half way > between the left and right shoulder, and the head is always on top of > it. Things like that might be interesting as well to keep in the > message, so that one can easily reproduce the previously mentioned > skeleton - if that is one of the use cases. > > Best regards, > > :-) Marcus > > > > 2011/3/26 Patrick Goebel > > > I see what you mean--the user looks more like a cactus than a > tree. :))) However, I think if you take the torso joint as the > root, don't you end up with a tree structure? e.g. > > torso->neck->head > torso->left_shoulder->left_elbow->left_hand > torso->right_shoulder->right_elbow->right_hand > torso->left_hip->left_knee->left_foot > torso->right_hip->right_knee->right_foot > > Maybe this is what you meant by it depends on how you define them. > > --patrick > > > On 03/26/2011 12:22 PM, David Lu!! wrote: >> It depends on how you define them. The skeleton visualized with >> the kinect ( >> http://www.ros.org/wiki/openni_tracker?action=AttachFile&do=get&target=nite.png >> ) >> isn't a tree, although it could be converted to be one, I suppose >> >> On Sat, Mar 26, 2011 at 1:11 PM, Patrick Goebel >> > wrote: >> >> Hi David, >> >> I agree it would be nice to have a standardized Skeleton >> message. If all skeleton's are trees (is this true?) then >> perhaps an existing tree message type could be used if it >> exists. KDL has kinematic chains and tf is already built >> around trees (right?). That's about as far as I've thought >> it through... >> >> --patrick >> >> >> On 03/22/2011 04:17 PM, David Lu!! wrote: >>> Hey Ros-users- >>> >>> Has there been any talk of creating a standardized Skeleton >>> message? Right now, it seems like the openni_tracker package >>> just publishes transforms. It seems like if the Kinect does >>> skeleton tracking, there should be a skeleton message. >>> >>> I know pi_tracker has its own Skeleton message, which looks >>> like it might fit the bill, although I don't think it >>> defines which parts are connected (hip bone is connected to >>> the thigh bone). >>> http://www.ros.org/doc/api/pi_tracker/html/msg/Skeleton.html >>> >>> It might be good to have for not only the Kinect, but for >>> other motion capture rigs (Vicon and the like). >>> >>> Are there any other similar message out there? >>> >>> -David!! >>> >>> >>> _______________________________________________ >>> ros-users mailing list >>> ros-users@code.ros.org >>> https://code.ros.org/mailman/listinfo/ros-users >> >> > > _______________________________________________ > ros-users mailing list > ros-users@code.ros.org > https://code.ros.org/mailman/listinfo/ros-users > > > > _______________________________________________ > ros-users mailing list > ros-users@code.ros.org > https://code.ros.org/mailman/listinfo/ros-users