[sane-devel] pixma MP810 working with sane

[Nicolas]

Le mardi 02 septembre 2008 à 21:36 -0400, m. allan noah a écrit :

> >
> > Last point concerning the white lines at the bottom: this is simply due
> > to the color planes shifting, as the backend algorithm to shift the
> > color planes uses only that portion of the image that will contain data
> > for the 3 colors. The bottom of the scanned image contains 2 and 1 color
> > zones only, due to the color shift.
> > So this is a little limitation for pixma CCD sensors, you must select a
> > scan zone a little bit bigger at the bottom, then remove the image
> > bottom white zone, that is padded on purpose by the backend to keep the
> > image size the frontend expects.
> > Another solution would have been to send to the frontend a smaller
> > image, but this may raise some errors then in the frontend ...
> >
> 
> i handle this specific issue for the old fujitsu M3091/2 by requesting
> a few more lines from the scanner than the user asked for, and throw
> away the extra ones after i shift the color planes.
> 
> allan

In fact, I did not dig too much into this for the moment, your approach
looks a good solution; asking for more lines to scan should be simple,
and I'll look on how to handle the end image scan condition in the
backend.

Nicolas