[sane-devel] Colored vertical stripes with Visioneer Xerox DocuMate 510

[chris guirl]

On Mon, Sep 27, 2010 at 12:31 PM, stef <stef.dev at free.fr> wrote:
>        forgot to check that your scanner was supported by the lexmark backend.
> Is it the case ? Sometimes scanners are merely relabeled models.

I don't know. On sane-project.org the model is listed as unsupported.
I have noticed the other Xerox DocuMate scanners are supported by the
avision backend. I'm unsure how to find out which backend is being
used when I run xsane.

>        Shading correction is varying from backend to backend with the
> capabilities of the underlying hardware.

I have thought that it could be the problem you described above - the
white-calibration area is dirty. However I can't imagine what kind of
dirt would make this pattern...I uploaded a sample here:

http://sqrville.org/software/colored_bands.png


Recently, I was able to make a few successful scans. I can't reproduce
this now or figure out what made it work and what made it stop working
later.


Doing some more testing, I noticed that the scanner has thinner bands
of discoloration (about half the width of before) at a resolution
setting of 600dpi.


It is also worth noting that, to get the scanner working at all, I had
to add this line to /lib/udev/rules.d/40-libsane.rules:

# Xerox DocuMate510
ATTRS{idVendor}=="04a7", ATTRS{idProduct}=="0446", ENV{libsane_matched}="yes"

Chris