That's great.

Please note that I did not have any issues with the method you used. My issue was only with the title of your post not being accurate. You used Python + OpenCV in addition to pre-un-swirled images.

To me at least, solving the problem with n lines of Python means that I email you a single swirled image and you, using Python as downloaded from python.org and nothing more, write a solver. The image doesn't even have to be JPG. It can be an easy to read non-compressed format. That'd be fine. But you'd have to un-swirl and do everything else, which is a lot more code.

Don't loose any sleep over this. It isn't important. Your original post was fantastic and very informative. My comments were only about the title and how, in every language camp, there's sometimes a tendency to look down upon other languages by quoting such nonsense as line counts.