I build skanpage from git, version is “skanpage 22.11.70” ( 22.11.70 is not in the version-list on bugs.kde.org) The tools misses a option for creating black and white (2-color/monochrom) scans. This saves a lot of disk-space and is sufficient for most non-colored document. There are scanner that do not support monochrom output and sane has the policy to not add functionality in the backends, but leave this for frontends. So providing a monochrom option in skanpage is the correct place. In my example, I got for a 1-page A4 pdf: skanpage grayscale: 9,1M black-and-white converted: 232K At first attempt a simple threshold at 50% would be O.K.
I would also be interested on this. Background: upgraded to Kubuntu 24.04 from Kubuntu 20.04. Finally Skanpage is available. I like some of its features (for example the multi-selection support in a single pass), but I really miss the ability to scan in black-and-white, simulating a photocopy machine. It seems like, in my case (I have a Canon CanoScan LiDE 110 scanner), this mode has been removed from the genesys SANE backend, so this mode (aka lineart mode) is now missing also from simple-scan and XSane!! :-( Maybe this is the reason why it's missing from Skanpage too...
(In reply to Mauro Molinari from comment #1) > It seems like, in my case (I have a Canon CanoScan LiDE 110 scanner), this > mode has been removed from the genesys SANE backend, so this mode (aka > lineart mode) is now missing also from simple-scan and XSane!! :-( Well, after deeper tests, it seems like actually it seems like simple-scan actually still applies some filter (in software I guess) so that white pages backgrounds appear white (and not gray). It would be nice to have the same in Skanpage too, at least an an option or additional mode.
It seems like a similar effect can be obtained by pushing the contrast level high enough (around 30 in my case) in the scanner additional settings. Anyway, perhaps having a way to simplify this for dummies with an additional mode would be nice. Sorry for these multiple comments, Bugzilla here does not allow to edit or delete previous comments...