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How to perform a good calibration for the Kinect?

asked 2013-03-06 01:57:37 -0500

anto1389 gravatar image

updated 2016-10-24 09:03:30 -0500

ngrennan gravatar image

Hello,

I am doing an app to merge point clouds. I am using kinect but i need to improve accuracy because I think my program is working (using Iterative closest point and detecting features such as SURF) but I don't get good results because the RGB camera transformation is not good enough to get "perfect point clouds" (I mean that i can see parts of objects at places where they shouldn't be, like seeing the edge of a box in the wall) This is the problem that make my results bad.

I have performed several calibration with the camera_calibration package in Ros fuerte to solve the problem but i get very different results and the calibration is done in the same way from each calibration. Some results:

[532.486920156757, 0, 313.943582352682, 0, 532.067717610884, 259.017556441565, 0, 0, 1]

[512.878303, 0 , 310.799036, 0, 513.067828 256.711335, 0, 0, 1]

In my opinion this results makes me think that i am doing something wrong in the calibration process but i follow exactly the tutorial http://www.ros.org/wiki/openni_launch/Tutorials/IntrinsicCalibration?action=show&redirect=openni_camera%2Fcalibration so i don't know what i am doing wrong.

Besides, there is some problems with the openni_launch as you can see at this post: http://answers.ros.org/question/53706/registered-depth-image-is-black/ I solved the problem but now i am wondering if the variable depth_regitration should be on or off.

Does anyone know what this hapens to me? could you give me any advice?

Thanks you very much! Antonio.

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answered 2013-03-06 05:21:35 -0500

updated 2013-03-06 05:22:02 -0500

You can use the cameracheck.py utility to assess the quality of your calibration. Unfortunately, that utility isn't documented very well.

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answered 2013-03-06 22:15:48 -0500

anto1389 gravatar image

updated 2013-03-06 22:16:20 -0500

Thank you very much!

I did what you suggest and i the highest values that i get are the followings:

Linearity RMS Error: 0.205 Pixels Reprojection RMS Error: 0.137 Pixels for RGB

Linearity RMS Error: 0.437 Pixels Reprojection RMS Error: 0.327 Pixels for IR

I think this values are good enough, right? And one more question, i did the calibration of the IR camera with the calibration file of the RGB camera loaded. Is it the right way to do it or i should calibrate the IR camera whithout loading the RGB calibration file?

Thanks again!

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Comments

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In the future, please edit your original question with any updates rather than posting them as a new answer. Yes, those error values look good. For calibrating the IR camera, it shouldn't matter if the RGB calibration is loaded.

Dan Lazewatsky gravatar image Dan Lazewatsky  ( 2013-03-07 02:35:52 -0500 )edit

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Asked: 2013-03-06 01:57:37 -0500

Seen: 2,744 times

Last updated: Mar 06 '13