(12-16-2023, 04:33 PM)Krikor Wrote: Maybe Ofnuts will be interested in the subject and create something along these lines :-)
Thought about it but the very complicated bit is that you also have to non-uniformly stretch things laterally. In this piece of squared paper, all the vertical lines should be regularly spaced:
But this is far from being really the case.
And I can't find a usable way to deduce the actual distortion from simple image characteristics, because if some of it is caused by the page curling, a good part of it is also due to the distance difference with the lens. I have done something similar in the past, for bottles and for scanners, but each works on only one kind of distortion (and in the case of the scanner, the distortion is constant).