I'm using a Fujitsu ScanSnap S1300i.
Using sudo as a temporary workaround to minimise any permissions problems:
$ sudo sane-find-scanner
found USB scanner (vendor=0x04c5 [FUJITSU], product=0x128d [ScanSnap S1300i]) at libusb:001:004
So I edited /etc/sane.d/epjitsu.conf and added:
firmware /usr/share/sane/epjitsu/1300i_0D12.nal
usb 0x04c5 0x128d
and copied 1300i_0D12.nal from a Windows install into /usr/share/sane/epjitsu/. (Actually I copied all the *.nal drivers, just in case it needed one of the others.)
$ sudo scanimage -L
device `epjitsu:libusb:001:004' is a FUJITSU ScanSnap S1300i scanner
$ sudo scanimage
scanimage: output is not a file, exiting
And running sudo simple-scan, skanlite or gscan2pdf all advance the document feed by a couple of centimeters, but then the feed halts and the fronted returns an I/O error of some kind.
So SANE seems to recognize the scanner and has some basic communication with it (the paper advances a couple of centimeters), but it doesn't scan.
Any suggestions about something I've missed out or how to get a proper scan output?
Additional info
$ scanimage -V
scanimage (sane-backends) 1.0.23; backend version 1.0.23
$ sudo skanlite
QDBusConnection: session D-Bus connection created before QCoreApplication. Application may misbehave
If I run sudo scanimage -v (I accidentally typed lowercase V when I was trying to obtain the version!) after the document has been advanced a couple of centimeters by sudo skanlite, then the scanimage command forces a complete document feed -- but no scan.