Lens correction for Xiaomi Yi

Contributing and equipment Action cameras
1

I recently switched from capturing with a smartphone to a Xiaomi Yi action camera. After applying some hacks, in particular correction of lens focus, the quality of the photos is rather good except the fisheye effect of the lens. When I activate the automatic correction by the camera, vertical lines are well corrected but lateral objects at the right and left edge of the picture are heavily distorted. This is particularly annoying for buildings and cars on the side of the road which are stretched in an unnatural way, example.

I read here on the forum that lens correction is done on the server, at least for some camera models. Apparently, this is not the case for the Xiaomi Yi. Are there plans to do it? And would the result be better than what produces the camera?

What are other users of the Yi doing? Upload unprocessed pictures or pictures corrected by the camera?

2

Hi !
I suggest to not enable the lens correction, because you lost a part of the picture. It’s how I do.

5

Hi!
How about change the lens for xiaomi yi?
You can check this lens,

6

This image is taken with Xiaomi Yi with undistort option turned off, as recommended:

Note that the building is perfectly straight. But at the borders, it is very weirdly curved. I guess mapillary’s undistortion camera model is incorrect?

7

I have an image where one can see it even better:

This post should be straigt. But it is not. Meaning, mapillary’s camera model is wrong.
@mapillary: is there anything I can do to support you to fix that?

9

Apparently, their model of at least that specific revision of that camera is so inaccurate that I do feel “wrong” is justified.

Apparently the parameters for the xiaoyi are not that precise, so it might be necessary to either estimate more precise parameters, or to estimate parameters for a Brown-Conrady model as for the GoPro 8. Any hints how I could proceed?