Because I started artwork with blender it became necessary to use my scanner. It is an antiquated piece of hardware (from the last millennium 1999). Up until now I did not use it very often, because I used a better scanner at the office. Or I started up Windows where it is working.
So basically scanning in Linux works out of the box if sane is installed, unless…
Starting up xsane from the menu I got an error message that did not tell me or anybody else anything. Something along the line device could not be initialized snapscan:libusb:006:002. Therefore I tried the same on the console in the hope to gain more information and I was successful:
[snapscan] Cannot open firmware file /usr/share/sane/snapscan/your-firmwarefile.bin.
[snapscan] Edit the firmware file entry in snapscan.conf.
With this message I searched the web and found Martin Meyerspeer had the same problem with another device. The basic is that you need a binary firmware file that is referenced. The file can be found on the accompanying driver CD. If your are lucky you did not throw it out already. In my case it was simple because the firmware files were not packed in an archive. There were however several of them. The SnapScan homepage helped me out locating the correct on. The rest is just following Martins description.