stripes in Avision-USB scans Was: [sane-devel] Re: Weird vertical stripes on Microtek ScanMaker X12USL (sane-1.05)

[Rene Rebe]

Hi all.

Is it possible that the stripes in the Avision-USB scans appear, because we do
no yet do any calibration? (The SCSI ones do not need / and even to do support
it). - But they are really black and very regular ... ???

http://www.rhrk.uni-kl.de/~bauerc/ct-cut.jpeg
http://www.neatech.nl/oss/HP5300C/stripe.jpg

Hm. Now when I watch to these two pictures they are not as black as the ones I
got via eMail. Seems to be clear that the USB scanners _simply_ need software
calibration and software color pack (color channel displacement).

I will do this in the next days ...

On Mon, 12 Nov 2001 06:25:15 +0100 (MET)
Novak Levente <lnovak@dragon.klte.hu> wrote:

> 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

k33p h4ck1n6 René

-- 
René Rebe (Registered Linux user: #127875 <http://counter.li.org>)

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