Page alignment sometimes goes wrong

Hi Zesje team,

The alignment of the pages from scan to the separate exercises sometimes fails, specifically when the bottom markers have dropped off the scan (when you put a large stack of paper in the scanner in batch mode, this sometimes happens). As example, I've attached 2 screenshots, one from the page as in the scan and the other as re-aligned by Zesje. It should be possible to get at least rotational alignment with only two markers (in 2D).

Kind regards,

Matthijs