[sane-devel] Canon DR-C125: Wrong colors when scanning Duplex

[el-ti]

Hello,

I have an appendix to make – maybe someone has a hint for me, why the
scanner behaves really strange:

Depending on the scanning resolution, the shifting on the color range is
different! I used the following command to test this:

scanimage --batch --source "ADF Duplex" --page-width 210
--page-height=297 -l 0 -t 0 -x 210 -y 297 --mode Color --resolution 300

Then I tried all available resolutions: 100, 150, 200, 240, 300, 400,
600. The results are strange:

Scanning with 100,150,200 gives me:
Blue -> Red
Red -> Green
Green -> Blue

Scanning with 300 and 400 gives me:
Blue -> Green
Green -> Red
Red -> Blue

And scanning with 240 and 600 shows the RIGHT colors.

How is that possible? And how can this problem be solved?


I installed Rolf Bensch’s PPA
(https://launchpad.net/~rolfbensch/+archive/ubuntu/sane-git), because it
solved the back page cutting problem when scanning Duplex. (see
http://permalink.gmane.org/gmane.comp.graphics.scanning.sane.devel/24903)

Other than that, I only installed the Canon "DR-C125 Driver for Linux
V1.0 (v1.0)".

Any hint is appreciated!
el-ti

Am 04.03.2016 um 10:59 schrieb el-ti:
> Dear Sane-developers and users,
>
> through this very helpful discussion
> (http://permalink.gmane.org/gmane.comp.graphics.scanning.sane.devel/24903),
> I managed to get my Canon Scanner working in Duplex without cutting 1 cm
> of the back page.
>
> Everything seems to work fine. However, I discovered a very strange
> behaviour regarding the colour management: When scanning in simplex
> mode, everything works fine. There is no page cutting and colours are as
> they should be. But in duplex mode, the colours are somehow shifted on
> the colour range: Blue is scanned as green, green is scanned as red, red
> is scanned as blue (for both back and front page).
>
> Is there an easy solution for this? Or did I forget to install something?
>
> Thank you very much!
> el-ti
>