[sane-devel] SANE2 and filmscanners

Oliver Rauch oliver.rauch@rauch-domain.de
Sat, 21 Dec 2002 16:09:25 +0100

On Saturday 21 December 2002 15:53, Jonathan Buzzard wrote:
> I have just taken a look at the SANE2 documentation, and a couple of
> things have struck me about lack of support for some features in
> filmscanners.
> The first is multipass scanning. Basically what happens here is that
> the scanner can read the values several times and returns the averaged
> result. This is useful for reducing noise from the A/D in the image
> data. Sometimes you can simulate this by making multiple passes and
> averaging the images, though it is not as good as it leads to a slight
> loss in resolution.

A backend should make an sane option for this feature.
There is no need to make a well known option for this.

> Batch scanning is the other. Here you might have a film or slide holder
> that has several separate images (or even an APS adaptor) and you
> just want to click a button to scan the lot. You need some way to
> communicate to the front end just how many images there are to scan
> etc. You also possibly need some way to allow the front end to pick
> an individual image to scan.

There is a flag that tells that there are more images.
To select the image #x the backend can create an option.
So there will be support for this. The question is if this should be a
well known option.

> Focusing, although most units are now autofocus, you can often override
> this for manual focusing if you want. I see no support of this in the
> proposed standard.

The backend can make a sane option form it. There is no need for a well k=

> I presume that a fourth infra-red channel would also be supported but c=
> not see anything about it in the documentation.

It is in (or was in, I did not read the last version)