Compensating scanner distortion - looking for volunteers with a scanner

[Krikor]

(03-05-2022, 02:18 PM)Ofnuts Wrote: Not too good, because you are adding the accuracy of your printer to the mix (not very trustable for end-user printers, especially inkjet ones). When you use off-the-shelf ruled paper the accuracy is the accuracy of the rules pattern which is normally very good.

The offset is the distance from your first anchor to the edge of the paper (which should normally be the edge of the scan, since to ensure verticality you have to tuck the side of the sheet against the side of the glass). But if you scanned a 21cm sheet with rules 14mm apart, the first rule in on the edge so offset should be 0? Or is that some printer margin?

The image I generated with the Gimp when printed had margins applied by the printer, even though I set the margins to zero.

The graph paper I have isn't cut properly, so there's no way to make a perfect fit parallel to the edge of the scanner.

I could try with a small notebook paper, inverting the sheet 90º while scanning.