Stereo Camera Extrinsics
-
I'm able to successfully calibrate the intrinsics for the stereo cameras, but I have not been able to do a successful extrinsics cal. I've tried focusing the lenses, tried different lighting, and tried different size calibration checkerboards and always fail the extrinsics cal. Reprojection error seems to consistently be 2+ and I get the following for an output. Any help would be greatly appreciated!
-
@bendraper Are you working with a VOXL 2 flight deck?
What kind of values are you getting for the right and left intrinsics?
Have you tried running the whole calibration a few times from a position where the left and right intrinsics are good? Sometimes it's as simple as a lighting issue and a small adjustment in the positioning of the device relative to the room's lighting can make a meaningful difference. And sometimes running just extrinsics will not produce an acceptable result even if your intrinsics are good.If you've already ran through several calibrations with no success, I wonder if there is any offset in the cameras' positioning. This can come from a physical offset in the stereo camera mounting, but it can sometimes be related to the internal construction of the sensor itself (sometimes the image sensor is offset to the lens which leads to the stereo images not being on the same plane).
If you send a screenshot of the camera calibration overlay screen with your calibration board's top edge aligned with the top edge of the camera's view, it would provide me some more insight into your particular setup. I'm specifically looking to see if, for example, on one side you might have the top of the board aligned with the top of the camera's view while the other camera's image may have the top edge of the board significantly over or under the top of the camera's view. -
@Dobry-Kolacz Interesting. Now that I'm looking at it, if I have the top edge of my board aligned with the top of the left stereo, there appears to be a gap above the board for the right stereo
-
@Dobry-Kolacz I think I'm getting close. Im pretty consistently getting a reprojection error ~0.6 at this point so still have yet to successfully calibrate stereo extrinsics. Tried new stereo cams, refocusing, different lighting, different scales of checkerboards, but can't get sub 0.5
