Bug 461359

Summary:	Option to scan in only black and white (not grayscale, only those two colors!)
Product:	[Applications] Skanpage	Reporter:	M G Berberich <kde>
Component:	general	Assignee:	Alexander Stippich <a.stippich>
Status:	CONFIRMED ---
Severity:	wishlist	CC:	mauromol, nate
Priority:	NOR
Version First Reported In:	unspecified
Target Milestone:	---
Platform:	Debian testing
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description M G Berberich 2022-11-03 13:04:46 UTC

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.

Comment 1 Mauro Molinari 2025-08-24 11:31:31 UTC

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...

Comment 2 Mauro Molinari 2025-08-24 11:42:56 UTC

(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.

Comment 3 Mauro Molinari 2025-08-24 11:49:58 UTC

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...