On Tue, Sep 02, 1997 at 10:48:00AM -0400, shendrix@gypsy.atlantic.infi.net wrote:
>
> In message <19970901104750.53420@drawbridge.in-berlin.de>
> woju@keep.in-berlin.de (> ) writes:
>
> > Just calcualte the Data the scanner needs to transfer.
> > As Far as I could find the Mustek Scanner justs uses async transfer
> > to the HOST which could be as slow as 1.5MB/S (even if you Adapter
> > could get up to 7MB/s )
> > An tiny Area of 1" times 1" brings you with 24 Bit and 1200 dpi Color
> > into 4320000 Bytes of Imagedata. if the scanner is able to scan that within
> > 1 Second the scanner needs to stop to get rid of the
> > Data.
>
> Well, under Windows95 it usually never did backtracking. When it did,
> it only backed up half the number of times it does with sane. This
> was with the little cheap controller it came with too.
I suspect the driver just got a lot more of Data in one chunk, or just
issued the READ Command almost immediatly after completition of the
previous one. If you watch the Statusbar in the Win95 tool, you might
have detected, that it just moves one or two times if you scane an area of
2x3 inches (estimate). I think they use an awful big buffer for
scanning, or at least TWAIN uses a real big one bevore sending it
to the applikation.
>
> There had got to be a way to get it as fast as under Windows. My scanner
> is backtracking every half inch sometimes. Under Win95 it always moved at
> least a couple of inches before backtracking.
I would love top get the gray mode working :-(.
But I think the Idea with using a MEG of SG Buffer is no good Idea.
I probably will experimet a bit on the comingf weekend. building a small
testprogramm which tries to get the READ Command issued as soon
as possible.
Gruss
Wolfgang
--1jdw2sOBCFtR2d/S
Content-Type: application/pgp-signature
-----BEGIN PGP SIGNATURE-----
Version: 2.6.3i
iQCVAwUBNAwxiTJlt0x7iX79AQEFYQP+Ony6tRi80iWm69kDqiu4EA7JRHOxlAzI
ALX7RNDlYCVsHqtj6ETzHdtjXk129u25o2oP/PitW+6nkIgny0PzVIvanOYWISGC
TDVdrr7Um9pFOUPZzdX0nt9djU4FSakLu+Hw4tzKO8sX0z1zpkzCSbSP7K+92g5c
/0+Tgk7Zvc4=
=qWKQ
-----END PGP SIGNATURE-----
--1jdw2sOBCFtR2d/S--
-- Source code, list archive, and docs: http://www.azstarnet.com/~axplinux/sane/ To unsubscribe: mail -s unsubscribe sane-devel-request@listserv.azstarnet.com