Ask Your Question

TF Frame Convention for Stereo Cameras

asked 2011-04-26 20:19:15 -0500

mkoval gravatar image

updated 2011-06-17 11:17:57 -0500

mmwise gravatar image

I am using a stereo camera for both stereo reconstruction and monocular image processing. Since I am not calibrating the pair of cameras twice, I am doing all of the monocular processing using the stereo calibration parameters. For the camera intrinsics, this works fine. I am not sure how to handle the extrinsics.

I would like to have the left and right cameras in different TF frames that correspond to their positions on my robot (e.g. /stereo_left_link and /stereo_right_link). Since the stereo baseline is encoded in the stereo calibration parameters, I am not sure stereo_image_proc will deal with the two images being in different TF frames.

What is the correct way to set the CameraInfo and Image message frame_ids to safely proceed to avoid being affected by the potential inconsistencies?

edit retag flag offensive close merge delete

4 Answers

Sort by ยป oldest newest most voted

answered 2011-06-30 05:53:02 -0500

tfoote gravatar image

You could check out uvc_camera's stereo_node as somewhere to start.

edit flag offensive delete link more

answered 2011-06-17 11:01:43 -0500

mmwise gravatar image

typically each camera in a stereo pair is assigned a different tf frame and the camera info for each camera contains the frame information

# Time of image acquisition, camera coordinate frame ID
Header header    # Header timestamp should be acquisition time of image
                 # Header frame_id should be optical frame of camera
                 # origin of frame should be optical center of camera
                 # +x should point to the right in the image
                 # +y should point down in the image
                 # +z should point into the plane of the image

stereo_image_proc listens on the right/camera_info and left/camera_info topics

edit flag offensive delete link more


I believe I have already tried this, but stereo_image_proc complains that the left and right TF frames do not match.
mkoval gravatar image mkoval  ( 2011-06-17 18:31:40 -0500 )edit
if you look at this question this is how we model the kinect for the turtlebot
mmwise gravatar image mmwise  ( 2011-06-18 09:07:37 -0500 )edit
Thanks for the link, but it is solving a different problem. I would like left/{image,camera_info} to have TF frame /stereo_left_link and right/{image,camera_info} to have TF frame /stereo_right_link. However, this triggers an assertion that left.frame != right.frame.
mkoval gravatar image mkoval  ( 2011-06-27 03:50:16 -0500 )edit

answered 2011-06-26 23:04:57 -0500

rajat gravatar image

Are you able to slove the problem, i am having the same problem , whenever i use stereo_image_proc , stereo vslam crashes saying that , assertion of failed .

Do you have any idea how to solve this problem?

edit flag offensive delete link more


I still haven't figured out how to get stereo_image_proc working without putting both cameras in the same TF frame.
mkoval gravatar image mkoval  ( 2011-06-27 03:46:47 -0500 )edit

answered 2011-06-27 23:57:41 -0500

rajat gravatar image

can you tell me how to put both the cameras in same TF frame .???

edit flag offensive delete link more

Your Answer

Please start posting anonymously - your entry will be published after you log in or create a new account.

Add Answer

Question Tools

1 follower


Asked: 2011-04-26 20:19:15 -0500

Seen: 2,183 times

Last updated: Jun 30 '11