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Calibrating Multiple Camera Groups

Posted: Sun Nov 14, 2010 9:43 am
by henderso

I am trying to use Tracking Tools (2.3) to calibrate 12 cameras.

I have the cameras organized using two camera groups. I am doing this because the groups use different illumination and exposure levels based on their proximity to the tracking volume. The groups allow for easy tuning.

However, it is not clear to me how to calibrate both groups. In the 3-wand calibration panel, I see the drop down for data acquitition camera group. I can calibrate one group at a time, but its not clear how should I proceed to combine the calibration.

Does anyone have any experience with this? I realize I can always move the camera to a single group, but would like to retain my split group control.



Re: Calibrating Multiple Camera Groups

Posted: Mon Nov 15, 2010 6:38 pm
by beckdo
Hey Steve,

In order to calibrate you're going to want them to be all in the same group. It important to solve them all at the same time in order to achieve the best tracking results. In the future I'm sure we'll have some additional tools for stitching separate calibration results together, but for now you're going to want to calibrate them at the same time. I will investigate having a selection for 'All camera groups' so that you can leave the the cameras in separate groups and still calibrate them all at the same time.

I would also like to facilitate an easy way to change the settings of multiple cameras at the same time. For example, select multiple cameras and set their settings at the same time. I'm sure we'll have this in future versions to make things easier.

Thanks for the feedback Steve, I will try to incorporate some improvements for the next version.

Re: Calibrating Multiple Camera Groups

Posted: Thu Nov 25, 2010 8:26 am
by maxlem
What about calibrating the two groups separately and then setting a common coordinate frame?

We tried quickly but the tracking was horrible, I will give it another try but are-you aware off anyone having success with that.

I currently don't have the 3-marker wand, I plan to purchase it, but could you disclose what distance separate the 3 markers so I can fake it, just to try it quickly.

We have a 24 camera setup (9 v100r2 and 15 v100) and a very large volume to cover, yet with only one group, most of these cams are redundant or waisted.

thank you

Re: Calibrating Multiple Camera Groups

Posted: Thu Nov 25, 2010 11:07 am
by maxlem
Nevermind for the wand's specs, found out required info in another forum thread. I built my own, seems to work fine.

My question about merging groups via their ground plane persists.


Re: Calibrating Multiple Camera Groups

Posted: Fri Nov 26, 2010 12:26 pm
by VincentG
Currently the software is still setup to calibrate them as one large group, which you then separate into sub groups.

Re: Calibrating Multiple Camera Groups

Posted: Wed Apr 13, 2011 2:44 pm
by micsfox
I have a similar problem. I am attempting to capture an area of 15 by 20 feet. If I try to calibrate the 18 cameras as one group, the calibration engine is unable to resolve the camera locations.

I've broken the space up into 15 by 10 foot sections with 9 cameras per group and calibrate them separately. I've attempted to "stitch" the groups together by placing a three marker rigid body in the overlapping space. While viewing the makers from the top, I use the capture volume translation to translate the groups until the 3 makers that group 1 sees and the 3 markers that group 2 sees are the same (overlapping).

When a trackable is in the overlapping area, the numbers jump around within about 3 mm (at the edges of the volume).

Has anyone attempted something similar? Is there a better way to do this?

Re: Calibrating Multiple Camera Groups

Posted: Thu Apr 14, 2011 3:51 pm
by NaturalPoint - Mike
Could you possibly post a diagram of your camera layout?

Re: Calibrating Multiple Camera Groups

Posted: Tue May 31, 2011 12:50 pm
by micsfox