[sane-devel] Digital ICE support

[Jonathan Buzzard]

ljm@xs4all.nl said:
> I recall that someone suggested that there should be something like a
> "mid-end" (like saned) that does the correction.  This would keep
> front-ends  simple and provide a moer uniform way to access  features
> like IR-correction.  =


A front end for scanning negatives and slides is not a particularly
good front end for scanning a sheet of A4 paper. The two are
wildly different. A library perhaps that front ends can use,
but we do not need new layers.

> I do not agree that there is little need for correction. When I try to
> correct  using the simple GIMP-plugin, I find that both brightness and
> contrast of the  IR-chanel are critcal and they must be set for each
> image separately. Also,  the exposure for the IR-chanel seems
> important. =


All that does is indicate weakness in the current algorithms. Clearly
if a commercial package the majority of which customers are buying
it because it is a *better* than that provided by the manufacture
has exactly three options "light", "medium" and "heavy" for IR
cleaning then there is no requirement for anything extra.

> Another reason why a mid-end could be better than the front-end is,
> that the  mid-end can scan always at full bit-resolution (12 bits on
> my LS-2000), do  the calculations and then round to 8 bits.

What the heck are you on about? The front end is *just* as capable
of doing this as any mid-end which just adds extra unnecessary
complexity.

> hm... maybe it's time for me to pick-up programming again... =


May I suggest with the strongest possible force that you download
Vuescan and try it. I have said it before and I will say it again
what Sane needs for filmscanning is a front end that looks and behaves
like this. It does *everything* that you need for scanning slides and
negatives.

I repeat a front end for scanning sheets of A4 paper is not what
you want for scanning a slide or negative. The two things are
sufficiently different to require different front ends.

JAB.

-- =

Jonathan A. Buzzard                 Email: jonathan (at) buzzard.me.uk
Northumberland, United Kingdom.       Tel: +44 1661-832195