[sane-devel] Digital ICE support

Major A andras@users.sourceforge.net
Mon, 1 Dec 2003 14:29:57 +0000

> I think that IR cleaning is a front end task personally. For starters
> you can tweek the IR cleaning parameters after the image has been
> scanned if you are not happy with the default ones, without having
> to scan the image again.

Agreed. I think there should be a sanei_* library that allows the code
to be used in frontends or meta-backends, whichever solution is
best. (Just think of a network scanner that is accessed by a handheld
device -- you don't want the IR cleaning to be done on the handheld.)

> Which is why IR cleaning should be a front end operation, with a set of
> default parameters for the most common scenario. I note that Vuescan
> only provides light, medium and heavy options in the front end for
> this. Clearly there is not a lot of need to twiddle parameters.

Nikonscan 2.x has no options at all, I think. I'm not sure about later

> I suspect that you are reading to much into what your particular scanner
> is doing. Infra-Red is a broad term describing a wide range of wavelengths.
> It starts just above the visible at 730nm or so and extends well
> over a 1000nm. I imagine what you see on a particular film depends
> heavily on the wavelength used which is likely to vary between scanners.

True. On the other hand, there isn't much room between the visible
range (down to about 730nm as you say) and the longest wavelength that
can be picked up by a CCD, so I think there isn't much variation
between scanners there.

> This might complicate doing IR in the frontend somewhat. However I suspect
> as long as the backend can communicate some parameters to the front end,
> then this can be taken care of.

We'll see, maybe an intelligent algorithm is good enough to find its
optimal parameters itself.

> I also note that IR cleaning is going to become a less specialised
> interest. Canon for one have started adding this to their flatbed
> scanners. As it cannot cost very much, one imagines that it will
> spread down the ranges to the cheaper models. Let's face it scanners
> are extremely cheap these days, and it is a way of differentiating
> your product in the market place.

That's an interesting development, and certainly worth looking into.


Major Andras
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