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How do you calibrate the extrinsic parameters?

asked 2014-10-28 03:28:48 -0500

Mehdi. gravatar image

I was trying to calibrate my camera mounted on the robot base so that I can get the transform from base_link to camera_link. i was looking for efficient and fast ways to do this and I found the following calibration algorithm which was useful because I could fix my pattern on the robot base directly and use a mirror to make it visible to the camera.

After doing some tests with that, the results were totally wrong. I also tested with a webcam mounted on my pc and I couldn't get good results.

How do the ROS community proceed with the extrinsic calibration of a monocular camera?

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answered 2014-10-28 04:35:54 -0500

gvdhoorn gravatar image

updated 2014-10-28 04:57:28 -0500

You might be interested in the industrial_calibration package from the ROS-Industrial community. Also: Industrial Calibration Library Update and Presentation.

It can be a bit involved to get it working at the moment, but that is being worked on. If you find you need help with anything, don't hesitate to send a mail to the ROS-Industrial mailing list (or ask here on ROS Answers of course).

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answered 2014-10-28 07:06:28 -0500

Airuno2L gravatar image

Hello,

I use this GUI based software for intrinsic and extrinsic camera parameters. I've used it a lot and have always had good results. I've only used it for pre-processing, I've never used it during real-time applications.

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I really hope they wrote that in a cross platform way

Mehdi. gravatar imageMehdi. ( 2014-10-28 20:42:13 -0500 )edit

The code was written for OpenCV 2.1 and was tested mostly on win32 (Windows XP, Windows Vista, Windows 7) platform. System Requirements: .Net Framework 3.5 SP1

Perhaps Wine or Mono could help here, but apparently no guarantees.

gvdhoorn gravatar imagegvdhoorn ( 2014-10-29 04:01:15 -0500 )edit
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answered 2015-02-11 10:59:24 -0500

gborghesan gravatar image

Hello,

I posted a similar question a while ago, and not having found a good solution, i coded one myself (unaware of ros industrial package). My solution needs a way to recover a frame through the camera, like ar_pose, plus a marker that is attached to the end effector (no need to know where, only that does not move during calibration). I checked it with Asus Xtion + ar_kinect the solution gives the camera to base frame transformation (plus the position of marker w.r.t. the robot link where the marker is attached, a data that is normally discarded)

see camera_robot_calibration

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Hello @gborghesan

I've been using your tool to calibrate a static camera with respect to robot coordinates. Could you help me out with some resources to understand the math behind optimization process to minimize the error

I have been consistently getting some translation error in one of the axes

avilash gravatar imageavilash ( 2018-08-02 13:23:42 -0500 )edit

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Asked: 2014-10-28 03:28:48 -0500

Seen: 1,776 times

Last updated: Oct 28 '14