[sane-devel] Canon LiDE 20 vertical lines

[Gerhard Jaeger]

Hi,

On Wednesday 03 August 2005 11:29, Udo Lütkemeier wrote:
> Hi Gerhard,
> 
> On Tue, 02.08.2005 09:12 +0200, Gerhard Jaeger wrote:
> > it's definitly not a SANE bug - it's a problem in fine calibration - if the position
> > of the fine-calibration strip is not excactly set, you might get those stripes - some
> > backends tryy to find it automagically, some set them directly.
> > 
> > For the plustek-backend, you might want to test with various values for
> > posShadingY (to set in the options section in plustek.conf), try values from 10 to 50...
> > and make sure to use the latest CVS snapshot - enable debug and try a scan, i.e.:
> > export SANE_DEBUG_PLUSTEK=19 ; xsane - send us the output.
> 
> thanks for your answer.
> Now, i have test posShadingY with various values from 10 to 50. The
> value 40 have a little bit reduce the vertical lines in the scans, but
> this option don't remove the extreme lines in my scans. Option 40 have
> from values 10 to 50 best the "best" result.
> 
> Output(very long) from "export SANE_DEBUG_PLUSTEK=19 ; xsane":

;)

> 
> http://www.udo-luetkemeier.de/temp/xsane.log
> 
> The picture from this scan(please zoom in):
> 
> http://www.udo-luetkemeier.de/temp/scan_with_sane-cvs.jpeg
> 
> This scan was made with following version:
> 
> sane-backends-2005-08-02.tar.gz
> 
> Then, I have this detected:
> 
> When I make with xsane a empty scan, I can better see the vertical
> lines. The following picture was the result of a scan with these
> settings in xsane:
> 
> "XSane mode" "Save",
> "Color",
> "Full color range",
> "testscan.jpeg",
> Step "+1",
> Type "JPEG",
> resolution "300" dpi,
> gamma "0.30",
> brightness "-100.0",
> contrast "100.0"
> 
> With these stettings, you can best see the lines without a
> picture/document.
> 
> http://www.udo-luetkemeier.de/temp/testscan.jpeg
> 
> Are the lines in testscan.jpeg normal or are this lines also _the_
> lines of my other scans?

these are the lines that should not appear :(
I've done some tests here with a LiDE30 and there were no lines, then I
connected the N670 (which should be the same device as the LiDE20) and
I see also these damned lines - I don't know currently where the problem
is - I have to do some more testing.

Ciao,
Gerhard