Crouton scanning with SANE Epson Perfection 2480

Some steps are from George Smart's blog and SANE website.

1. install packages:
   sudo apt-get install xsane sane libsane-extras sane-utils netpbm libusb
2. download the firmware:'Esfw41.bin'
3. copy firmware:
   sudo cp -v Esfw41.bin /lib/firmware/esfw41.bin
4. modify the config file: add 'firmware /lib/firmware/esfw41.bin' to '/etc/sane.d/snapscan.conf'
5. find the scanner:
   lsusb
   sane-find-scanner
6. find the device:
   scanimage -L
   In my case(Epson Perfection 2480), it's 'snapscan:libusb:001:005'
7. test it:
   sudo scanimage -d snapscan:libusb:001:005 --format pnm > out.pnm
8. convert it to jpg:
   pnmtojpeg out.pnm > out.jpg
   or
   sudo scanimage -d snapscan:libusb:001:005 --mode color -x 215 -y 285 --resolution 600 |pnmtojpeg >out.jpg
9. done.

Epson package(iscan) looks not a must, neither does X. maybe xsane either