Shift in the Mercator Projection

[jeychandar]

@meyerj I am using insta360 air to record the rosbag. when I try to play I found that it has vertical shift in the mercator projection. I attached the image below here. Could you please help me to resolve this shift issue. Thanks in advance

[Martin-Oehler]

It looks like your external calibration (the transformation between both camera centers) is off. Are you using the URDF provided with this package or did you calibrate yourself?

[jeychandar]

I have not changed anything I am just using the parameters you provided in this repo.

[Martin-Oehler]

Due to manufacturing tolerances, differences between Insta360 Air units might be big enough to result in this problem. You will have to calibrate your cameras using kalibr and update the calibration. To ensure sufficient overlap between images, you will need an additional Insta360 Air fixed at a 90° angle to the first one.

Alternatively, you can try to manually change the parameters here and see if things improve.

[jeychandar]

Is it necessary to be two insta360 air to calibrate. I have tried to calibrate with single insta360 air but it throws attribute['weight']error.

[Martin-Oehler]

I don't know about the error, but for extrinsic calibration, you will need overlap between the individual cameras. The Insta360 Air by itself has only very little overlap at the edges of the lenses, which is not sufficient for a proper calibration. Therefore, you need to add other cameras to have an indirect connection (Air cam 1 -> other cam -> air cam 2). It does not need to be another Insta360 Air. Just any other camera, rigidly affixed, will do.

[jeychandar]

Thanks for your help.I will try to calibrate and check.