[sane-devel] xsane-0.87 released

Rene Rebe rene.rebe@gmx.net
Tue, 16 Jul 2002 20:25:06 +0200 (CEST)

Hi Henning.

Speaking about the preview feature of xsane ... - for color scans
xsane does a scan with gamma=1 and creates a software preview when the
user modifes the gamma value. But for my avision backend the scanned
images are not as light as they are in the xsane preview. Although the
scan looks reasonable for the gamma value.

So is the software simulation much too light (because of the loss of
precision) or are the Avision scanners interpreting the values in a
different way I think, and so the scanned images are just too dark for
the gamma-table I send?

Thanks for comments ;-)

On: Tue, 16 Jul 2002 18:07:31 +0200,
    Oliver Rauch <oliver.rauch@rauch-domain.de> wrote:
> Henning Meier-Geinitz schrieb:
> Hello Henning,
> a threshold value is something that is clear to me.
> a brightness value can be implemented in a comparable way to a threshold value.
> but what makes a contrast value for a lineart image?
> The contrast is defined by the two colors that are used: black and white.
> I do not understand what the contrast value does change.
> grep  -i threshold *.c | cut -d: -f1 | sort -u | wc -l
> show that 32 backends have the text "threshold" included.
> We have about 50 backends defined.
> We will have to make it common one day. If you like to change it in the
> mustek backends then the users will have the advantage that they can do
> a preview scan in grayscale mode with xsane and they can change the
> threshold without doing a new scan.
> Bye
> Oliver

k33p h4ck1n6 -- René

René Rebe (Registered Linux user: #248718 <http://counter.li.org>)
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