Am 17.02.22 um 03:02 schrieb David Ward:
It seems very likely that the original problem is an upstream bug in
SANE. There are a few issues reported there specifically against the
Canon LiDE 220 that sound very similar:
https://gitlab.com/sane-project/backends/-/issues/439
https://gitlab.com/sane-project/backends/-/issues/518
These upstream bugs apparently affect all resolutions (they were
reported at 300 and 600 dpi). The problem I see only happens above 1200 dpi.
On 12/9/2020 8:22 AM, Philipp Klaus Krause wrote:
Summary: The situation improved somewhat, but is still far from perfect:
There is still an odd waiting time when starting to scan at 2400 or 4800
(at 1200 and below the scan starts nearly instantly, after less than
second). At 4800 colors ar wrong.
Once one of these problems appears, it affects all resolutions until
restarting xsane:
Having done a scan at 2400 or 4800, subsequent scans at lower
resolutions also have the waiting time at the start. Having done a scan
at 2400 or 4800, where black appeared as bordeaux, subsequent scans at
lower resolutions also have wrong colors.
You mentioned that you are using GIMP to launch xsane. The problem with
the colors could be occurring there. Can we rule that out? What happens
if you run "scanimage" from the command-line — does it produce an image
with the correct colors?
Due to a gimp bug
(https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=994429) I haven't
launched xsane from gimp for a while.
But your request still helped track down the issue a bit further:
I have not been able to reproduce the bug using scanimage from the
command line¹ (did various scans at 2400 and 4800 dpi today, using
Debian testing). Both speed and color were fine using scanimage from the
command line.
But I can reproduce the bug using xsane started from the command line
(also tested today). I also got a segfault in xsane once (just at the
end of a 4800 dpi scan).
Philipp
¹ I do get a different bug with scanimage though: For a full-size scan
at 4800 dpi, two thirds of the image are just gray.
