Technical notes on computer vision problems and how they were solved, with figures you can explore.
Article
With fisheye cameras, a parking car sees much more of the ground around it than with ordinary ones. The catch is that the curb looks much closer than it is. With an interactive figure and some math, we trace each pixel back to the curb's true distance, even at the edges of the view, where OpenCV's one-liner gives up.
Nordic Gradient