Instalaremos como ejemplo un escaner Epson 3490.
 

Instalamos las utilidades de SANE:
# aptitude install sane-utils

 

Damos permisos a los usuarios:
# vi /etc/group

scanner:x:110:guimi
saned:x:113:guimi

 

Verificamos la conexion con el scan:
# lsusb

 Bus 005 Device 002: ID 04b8:0122 Seiko Epson Corp. 

# ls -ltr /proc/bus/usb/005/002

-rw-r--r-- 1 root root 57 2007-05-28 12:39 /proc/bus/usb/005/002

# ls -ltr /proc/bus/usb/005/

total 0
-rw-r--r-- 1 root root 43 2007-05-28 12:39 001
-rw-r--r-- 1 root root 57 2007-05-28 12:39 002

 
Comprobamos que SANE reconoce el scan:
# grep 3490 /etc/sane.d/hotplug/libsane.db -A 1

 # Epson Perfection 3490 | Epson Perfection 3590
0x04b8	0x0122	root:scanner	0664	

# grep 3490 /etc/udev/libsane.rules -A 1

# Epson Perfection 3490 | Epson Perfection 3590
SYSFS{idVendor}=="04b8", SYSFS{idProduct}=="0122", MODE="664", GROUP="scanner"

 
Probamos a detectarlo como usuario:
$ sane-find-scanner

found USB scanner (vendor=0x04b8, product=0x0122) at libusb:005:002
  # Your USB scanner was (probably) detected. It may or may not be supported by
  # SANE. Try scanimage -L and read the backend's manpage.

$ scanimage -L

device `snapscan:libusb:005:002' is a EPSON EPSON Scanner flatbed scanner

$ scanimage -T

[snapscan] download_firmware: No firmware entry found in config file snapscan.conf.
scanimage: open of device snapscan:libusb:005:002 failed: Invalid argument

 
Cargamos el firmware copiando el driver de %WINDOWS%\system32:
# mkdir /usr/share/sane/snapscan
# cp Esfw52.bin /usr/share/sane/snapscan/epson3490_firmware.bin
# vi /etc/sane.d/snapscan.conf

#firmware /usr/share/sane/snapscan/your-firmwarefile.bin
firmware /usr/share/sane/snapscan/epson3490_firmware.bin

 
Volvemos a probar como usuario y ya funciona:
$ scanimage -T

[snapscan] Scanner warming up - waiting 8 seconds.
scanimage: scanning image of size 2552x3507 pixels at 24 bits/pixel
scanimage: acquiring RGB frame, 8 bits/sample
scanimage: reading one scanline, 7656 bytes...  PASS
scanimage: reading one byte...          PASS
scanimage: stepped read, 2 bytes...     PASS
(...)
scanimage: stepped read, 3 bytes...     PASS

 
Para utilizar el escaner desde el escritorio podemos instalar xsane:
# aptitude install xsane

Instalar un escaner en GNU/Linux, Configurar scanner en Linux, scaner, scan, Linux