[sane-devel] Canon LiDE 20 vertical lines

[Udo Lütkemeier]

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?

With best regards,

Udo Lütkemeier

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Udo Lütkemeier			       http://www.udo-luetkemeier.de
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