[sane-devel] Canon LIDA 20 (plustek) scan quality

[Alvaro Figueiredo]

At Tue 11 Jan 2005 06:25, Gerhard Jaeger wrote:
> Hi,
>
> On Tuesday 11 January 2005 05:41, Alvaro Figueiredo wrote:
> > Hi, all.
> >
> > I recently bought a Canon LIDA 20, a USB scanner. It readly
> > worked on my Linux 2.6 box, but its scan quality is really much
> > worse than Windows 98 driver's scan output. It is a dual boot
> > box.
> >
> > I am scanning regular text documents, like the sample bellow.
> >
> > scanimage --resolution 300 --mode Binary -x 210mm -y 297mm
> >
> > The Windows output is almost perfect, like a photocopy. The
> > sane's output seems to have much less resolution and misses
> > some portions of text that is not black. I am using the same
> > mode (lineart) and resolution (300dpi) on Linux / sane and
> > Windows. I can send both outputs, if anyone request it (near
> > 150k each, in PDF).
>
> please send it to me.
>

I made available three documents scanned on Linux (sane) and on 
Windows (manufacturer's driver). They are doc1???.pdf, doc2???.pdf 
and doc3???.pdf (??? is lin or win). I did ran a sample with debug 
enabled and published it all at:

http://alvarof.freeshell.org/sane/

> > I have no scanning experience, but I had tried almost all
> > options of scanimage without significative improvement.
> >
> > Am I missing something, here?
>
> Probably not.
>
> > Follow some system information.
> >
> > scanimage --version
> > scanimage (sane-backends) 1.0.14; backend version 1.0.14
>
> you might update to 1.0.15.
>

My Linux distro uses RPM, and I already keep it updated. I will try 
upgrade sane later on, with alternative packages.

> > scanimage -L
> > device `plustek:libusb:001:004' is a Canon N670U/N676U/LiDE20
> > USB flatbed scanner
> >
> > sane-find-scanner
> > found USB scanner (vendor=0x04a9 [Canon], product=0x220d
> > [CanoScan], chip=LM9832/3) at libusb:001:004
>
> Could you please to the scan again, enabling the debug output,
> and send me that too? export SANE_DEBUG_PLUSTEK=20
>
> Ciao,
> Gerhard

I did not scanned color pictures yet. I do not know if it presents 
some anomaly.

Please, let me know if I may help you with more information or if I 
could make more tests.

Thank You by your attention.

-- 
Alvaro Figueiredo
alvarof@freeshell.org