Re: DS-7 Backend

Matt Martin (mmartin@Calvin.SFC.Lehigh.Edu)
Fri, 8 May 1998 00:55:24 -0400 (EDT)

> What I would like to see is a library of conversion filters, e.g.,
> JPG->PPM, FlashPix->PPM, PPM->JPG, PPM->FlashPix and so on (much like
> the PNM utilities). Then, a frontend could declare what image types
> it supports and the backend declares what image type it supports. If
> there is a mismatch, a pipeline of available filters can be
> constructed that will make it possible for the frontend to interpret
> the backends data. E.g., xscanimage when running under GIMP would
> declare "PPM" only, then when you'd attempt to read from a JPG-only
> camera, the JPG->PPM filter would be used.
>

Looks like right now the entire image must be buffered,converted and
then sent to the frontend piecemeal (kind of like the fake pnm
driver). Can't imagine that the current API would allow any other
approach, as it "steals" away the data as soon as it arrives from the
scanner; no chance for subsequent manipulation.

Wondering if Rasterman's Imlib would be a good way to go for image
conversion. Supposedly it can display and convert all kinds of
formats. (haven't programmed with it, only used it)

> Since this would be a fairly significant change to the SANE API, I
> think we should do this extension as part of a next major revision.
> If you're interested in working on this, you could design the DS-7
> backend in a way that works with the existing SANE (i.e., JPG always
> gets converted to PPM) but makes it easy to adapt to the new
> environment once work on the extended API begins.
>

Might be easier to re-write when the new API is defined... (any plans?)
For now I will try to shoehorn some conversion into the backend.

Thanks for the advice.
Matt Martin
matt.martin@ieee.org

Lehigh U. Microelectronics Research Lab "The Clubhouse"
16A Memorial Dr. E., Bethlehem,PA,18015 126 East 4th St.
mmartin @ calvin.sfc.lehigh.edu Bethlehem, PA,18015-1702
Work:(610) 758-3951 (Office) MGM1 @ LEHIGH.EDU
-4518 (Lab) Home: (610) 758-9662
WWW: "http://www.lehigh.edu/~mgm1/mgm1.html" AIM ID: MmAaRtTtIN
PGP Public key at "finger mmartin@calvin.sfc.lehigh.edu"

--
Source code, list archive, and docs: http://www.mostang.com/sane/
To unsubscribe: echo unsubscribe sane-devel | mail majordomo@mostang.com