AutoCalibration of stereo cameras

[lavrent...@gmail.com]

So I have a video sequence of stereo camera, and I know intrinsics of the cameras pretty well. My goal is to build a reconstruction and find out relative pose of left and right camera (assuming that it is constant across all views). What is the best way to implement this (enforce constraint of constant relative pose of left and right cameras)?

[lavrent...@gmail.com]

I see that there was a similar discussion about this https://groups.google.com/forum/#!topic/theia-vision-library/AtMKgidUs_I

To clarify I'm looking for some hints how to incorporate this into incremental SfM pipeline.

[Chris Sweeney]

Theia is unfortunately not equipped to handle stereo cameras right now and it would take a lot of code modification to make it work natively. If you're interested, I could provide some insight for how you might make those changes but it will be substantial.

Chris

On Mon, Jun 4, 2018, 2:59 PM <lavrent...@gmail.com> wrote:

I see that there was a similar discussion about this https://groups.google.com/forum/#!topic/theia-vision-library/AtMKgidUs_I

To clarify I'm looking for some hints how to incorporate this into incremental SfM pipeline.

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[lavrent...@gmail.com]

Actually, I've been trying to extract the information about relative camera position using estimation of TwoViewInfo (using only 2 frames) and the results that I'm getting look generally good, but I'm looking for ways to improve it.

And I've spotted BundleAdjustTwoViewInfoAngular in the repo (https://github.com/sweeneychris/TheiaSfM/blob/master/src/theia/sfm/bundle_adjustment/bundle_adjust_two_views.cc#L194)
Can somebody explain what it does, and specifically what paper does this (https://github.com/sweeneychris/TheiaSfM/blob/master/src/theia/sfm/bundle_adjustment/angular_epipolar_error.h#L67) refer to?

[Chris Sweeney]

The paper is noted here: https://github.com/sweeneychris/TheiaSfM/blob/master/src/theia/sfm/bundle_adjustment/bundle_adjust_two_views.h#L71

I did not have much success with the angular bundle adjustment so it is not being used in the active reconstruction pipeline

[lavrent...@gmail.com]

This is probably not very useful since angular bundle adjustment isn't being used, but still:

I believe there is typo in the AngularEpipolarError class
https://github.com/sweeneychris/TheiaSfM/blob/master/src/theia/sfm/bundle_adjustment/angular_epipolar_error.h#L74
instead of (rotation_matrix * feature2)
should be (rotation_matrix.transpose() * feature2)

But it still return wrong results for some unknown reason for me. For my stereo setup with cameras shifted along x axis it returns translation vector along z axis, and this is weird.