[sane-devel] SANE2 standard completion

[Rene Rebe]

On 28.03.2008, at 19:02, Alessandro Zummo wrote:

> On Fri, 28 Mar 2008 15:49:17 +0100
> Rene Rebe <rene at exactcode.de> wrote:
>
>>
>> Right now the only thing I miss are marks for infra-red frames, and
>> maybe
>> a ability to pass duplex data without buffering the rear side, which
>> becomes
>> even more of a problem with the next generation, higher end devices I
>> got
>
> I'm interested in this.. you receive the data of two pages at
> the same time? It's interleaved in some way?

I speak about the duplex devices here, which have 2 CCDs (or
similar and scan both sides at the same time (long supported by
the Avision backend, btw. :-)

Avision developed several ways to transfer the duplex data (aside
from the few, trivial) paper flipping devices with just a single CCD),
for some they buffer the page in-memory inside the scanner, for newer
ones there are several interlaced variants.

For the interlaced variants I so far buffer the rear stripes in the  
backend
and return the backed data every second frame.

Probably the fujitsu backend does something similar.

Yours,

-- 
   René Rebe - ExactCODE GmbH - Europe, Germany, Berlin
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