Re: Starting a discussion about SANE and TWAIN...

Andreas Beck (becka@rz.uni-duesseldorf.de)
Fri, 13 Aug 1999 16:39:04 +0200

> If I read correctly Andy stated that it is possible to have
> something like a TWAIN backend for SANE.

No. To my knowledge, this is not possible.

> The other way round, i.e. a TWAIN frontend for SANE is trivial as
> I understand. Why do not implement this as a first step?

Yes. That's what I'm asking for. But it needs someone with good knowledge
about the TWAIN API. I volunteer to help that person with all questions of
SANE interfacing. To do it "right", we will need to define a "remote
control API" for each architecture we want to run on, which will allow
the TWAIN layer to interface with an arbitrary SANE frontend.

> If the aim is a standard cross-(all)-platform solution, introduce
> SANE softly and stable. There is an exploding market with NT-networks
> using Linux servers, which will readily accept this. There even a Win
> only TWAIN frontend would win.

That is probably what one should do for the windows operating system:

Write a generic SANE frontend, that exports a TWAIN interface. As SANE
seems to compile with cywin, this gives instant access to all networked
SANE scanners using the net backend. Thus it for now covers the scope
of WinSANE, which hasn't evolved a lot recently.

When we get around to including the Windows native HAL into the SANE HAL,
we can as well use all SANE drivers on Windows from standard TWAIN
applications.

Once we are there. It is possible for manufacturers to write their drivers
in SANE style, with a separated front- and backend. They will run on
windows, which is their primary concern. But the backend should then
as well compile on all other SANE platforms, so supporting them is easy.

For having TWAIN style access to scanners on Unix (thus allowing application
programmers to port their programs more easily), we'd need the
abovementioned "remote control" for SANE frontends.

Both projects are pretty separate and can be done in parallel. Again I
volunteer to help anyone with the SANE issues, but we'll need someone to
help with the TWAIN issues as well.

Maybe it would be useful to have a small snippet of code that shows how a
typical Win application calls up a TWAIN source.

A complete API listing would as well be useful.

CU, ANdy

-- 
= Andreas Beck                    |  Email :  <andreas.beck@ggi-project.org> =

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