David> Could somebody with Linux and a Mustek 3-pass scanner try the
David> code below and tell me how/if it works?
Mathias> I tested it very shortly and I believe that scanning has
Mathias> become faster :-) -- but it seems to be memory dependend
Mathias> :-( I have only 40MB)... scanimage --mode color
Mathias> --resolution 300 dpi >/dev/null needs 3:45 min.
Wow, it used to take 15 minutes, right? That would be a nice
improvement. How does it compare to the scan times with other
programs?
Mathias> The system crashes sometimes (so on a 600 dpi scan in the
Mathias> middle of the third pass) but this may be kernel instabilities ?
I certainly haven't seen any crashes due to SANE. Do you mean the
_entire_ system crashes or just some tasks get killed? The latter
happens under Linux when running out of swap space.
Mathias> The first pass is done really fast, the second and third pass
Mathias> becomes slower. It seems to depend on how fast the system
Mathias> is able to swap, because during one pass the scanner
Mathias> sometimes gets fast for some seconds and becomes slow
Mathias> again. I assume that a 128 MB System won`t have
Mathias> performance problems unless it is driving StarOffice :-).
This makes sense with the current buffering scheme: the first pass
simply writes out data. The second and third passes in contrast have
to read the existing data, add info for one channel, then write it
back out. There was some discussion to implement a better buffering
scheme that would fix such problems for scanimage, but AFAIK, nobody
has done it so far. If you scan with xscanimage instead of scanimage,
the swap problem _ought_ to go away. I'd be interested to hear how
well it works under GIMP as well.
Mathias> Sorry but I can`t provide debug output or look deeper into
Mathias> it because I`m going on holiday tomorrow... Nice to see
Mathias> 3-pass patches :-)...
Well, enjoy your vacation then! Thanks for testing things!
--david
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