[sane-devel] Scanning with 16 bits color depth (2 bytes/color)

[Nicolas]

Back on this topic, TPU scan with pixma backend (on MP970):

We have currently reached the following point:

- TPU works OK at 24 bits/pixels (8 bits color depth), with at least
scanimage and Xsane (bits variations between colors are normal, as per
variation of the negative color model, correctly handled then by Xsane).
This is currently in the CVS version.

- TPU at 48 bits/pixels (16 bits color depth) under debug, works OK with
scanimage. 
We have now issues when trying to use Xsane. Horizontal color or noisy
stripes (~20 lines each) appear on the image, looking like some buffer
crash or so. 
I use Xsane 0.995
I've tried also on an XP box with Xsane-win32 (0.991), and it looks I do
not get those stripes, the image seems correct.

Any one would have an idea on what's happening with Xsane on Linux ?

FYI, the pixma backend uses the RGB color model, to send the frontend
RGB frames.


Le samedi 04 octobre 2008 à 19:07 -0400, m. allan noah a écrit :
> pnm format is generally host byte order specific. i bet you get big
> endian data from scanner, but you are on a little endian platform?
> 
> allan
> 
> On Sat, Oct 4, 2008 at 5:41 PM, Nicolas <nicolas.martin at freesurf.fr> wrote:
> > We are doing first tests in 16 bits mode with TPU on PIXMA MP970, but
> > the images obtained are messed up. I'm wondering if this comes from the
> > image format.
> > Which backend are you using for 16 bits scans ?
> > Maybe you know also which image format it uses ?
> >
> >
> >
> > Le samedi 04 octobre 2008 à 06:57 +0200, stef a écrit :
> >> Le Friday 03 October 2008 08:15:34 Nicolas, vous avez écrit :
> >> > Ok, thanks a lot for this clarification, I understand that 16 bits per
> >> > color images are supported by the standard, so no special scaling would
> >> > be necessary.
> >> >
> >> > But do you or someone knows if scanimage or Xsane can handle 16 bits per
> >> > color appropriately ?
> >> >
> >> > Nicolas
> >> >
> >>
> >>       Hello,
> >>
> >>       I know that XSane and kooka handle 16 bits scans nicely. I use both for 16
> >> bits scans with the genesys backend.
> >>
> >> Regards,
> >>       Stef
> >>
> >
> >
> > --
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> 
> 
>