[sane-devel] Re: Weird vertical stripes on Microtek ScanMaker X12USL (sane-1.05)

[Novak Levente]

On Sun, 11 Nov 2001, Michael Thomson wrote:

> Hi Henning
> 
> Thanks for your tips - I've successfully built & installed
> sane-backends-1.06 and sane-frontends-1.06 as well as xsane-0.80 now.
> 
> Sadly I'm still getting weird stripes, but I found a previous discussion on
> this and I've mailed the folk involved to see if they made any progress.
> 
> To answer your question, sane-1.05 came precompiled with my distribution:
> Yellow Dog Linux 2.1 from Terrasoft (www.yellowdoglinux.com)
> 

Usually if you get vertical stripes in scanned images, it means that there
is no (or there is a wrong type of) shading correction. Every CCD or CIS
is composed of photoelements slightly different in characteristics, so
usually the scanned images are not directly converted to images but
corrected for lamp and sensor unevenness.
I had similar problems with Microtek Phantom 636cx, until Karsten Festag
corrected the shading function in microtek2. Since then, everything is
working fine.
The only strange thing in your image is that the stripes are not dark like
in my case but coloured. It seems to me it is a wrong (buggy?) shading
correction rather than a non-existant one. Or a communication problem
between the scanner and the computer which corrupts the data?


Levente