How to determine the horizon through the filters on the camera?

Question

Iron

The camera at an altitude of about 100 meters looks at the horizon. With the help of a program written in OpenCV, it reveals the horizon as a line.
ps I can't find materials of other similar developments. If you know where there is such a post, I will be grateful for the link.

Answer 1

It is not entirely clear what is meant by "through the filters on the camera", if we are talking about software filters, then I think Gaussian smoothing should help, after separating the "lighter" half from the "darker", everything in the middle will be the horizon