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

[m. allan noah]

Canon scanners often have this variable interlacing at different
resolutions, so I am not surprised to see this. However, this
particular scanner has the weirdest interlacing that canon does. If
you can compile from source, I can send you some patches to try. See
http://www.sane-project.org/README.linux

allan

On Tue, Mar 15, 2016 at 9:17 AM, el-ti <tl at ewetel.net> wrote:
> Unfortunately, yes.
>
> I uninstalled "cndrvsane-drc125" and restartet the system. The color shift is still there.
>
> And there is also the problem, that there is a 1/2 cm cut on the long edge of the scanned page (the "duplex-offset" option only handles the short edge) – but I guess this is another problem.
>
> If you need more information, do not hesitate to tell me.
>
> el-ti
>
> Am 15.03.2016 um 12:41 schrieb m. allan noah:
>> If you uninstall the Canon "DR-C125 Driver for Linux V1.0 (v1.0)"
>> software, does this color shift still happen?
>>
>> allan
>>
>> On Tue, Mar 15, 2016 at 7:37 AM, el-ti <tl at ewetel.net> wrote:
>> > The system is using the libsane version from the PPA: 1.0.26-git20160305-wily0
>> >
>> > It was installed above the one from Ubuntu’s repositories, when I added the PPA.
>> >
>> > el-ti
>> >
>> > Am 15.03.2016 um 12:22 schrieb m. allan noah:
>> >> You have installed both sane-backends, and canon's driver? Which one
>> >> are you using? Assuming you are actually using sane-backends, we will
>> >> have to modify the code to control the color descrambling.
>> >>
>> >> allan
>> >>
>> >> On Tue, Mar 15, 2016 at 6:08 AM, el-ti <tl at ewetel.net> wrote:
>> >>> 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
>> >>>>
>> >>>
>> >>>
>> >>> --
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>> >>> http://lists.alioth.debian.org/cgi-bin/mailman/listinfo/sane-devel
>> >>> Unsubscribe: Send mail with subject "unsubscribe your_password"
>> >>>              to sane-devel-request at lists.alioth.debian.org
>> >>
>> >>
>> >>
>> >
>>
>>
>>
>



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