[sane-devel] Acer 620ST

[Oliver Schwartz]

Hi,

> I have got a scanner called Acer 620 ST.
> It's running properly using the snapscan-backend.
> sgcheck shows something like:  FlatbedScanner17
>
> My question is:
> Why the xsane, saintwain or xscanimage frontends "just" provide the
> maximum scanning resolution of 600 dpi, though the scanner itself
> is capable to scan at 1200dpi (unfortunally only under Windows,
> yet)? Is there a way to include that resolution as well?

The scanner has a resolution of 600x1200 dpi, i.e. the optical=20
resolution is 600 dpi whereas the stepper motor that moves the tray=20
has a resolution of 1200 dpi.=20

The backend is currently limited to the optical resolution of the=20
scanner. All higher resolution require an interpolation algorithm in=20
the backend, and I never got around to implement a decent one. It's=20
on my list though, but with very low priority.

You also have to consider that the "real" resolution of the scanner is=20
probably less than the mechanical resolution anyway. There was a test=20
once in c't (german computer magazine) where they measured the real=20
resolution of scanners. Most scanners have difficulties in reaching=20
even 600 dpi, due to limitation of the optics involved.

Regards,

Oliver