[sane-devel] pixma backend: -x/y auto advertised but not available / how to crop?

[Manuel Reiter]

I'm using saned with a Pixma MP610 all-in-one on a Raspberry Pi 3 
running an up-to-date Rasbian Jessie. scanimage --help shows me the 
following options for Geometry:

[...]
Options specific to device `net:localhost:pixma:04A91725_414EE7':
[...]
   Geometry:
     -l auto|0..216.069mm [0]
         Top-left x position of scan area.
     -t auto|0..297.011mm [0]
         Top-left y position of scan area.
     -x auto|0..216.069mm [216.069]
         Width of scan-area.
     -y auto|0..297.011mm [297.011]
         Height of scan-area.
[...]

However, trying to actually use "-x auto" results in an error:

------snip
reiter at hive:~ $ scanimage -d net:localhost:pixma --mode Color \
--resolution 300 -l auto -t auto -x auto -y auto > /dev/null
scanimage: option --x: bad option value (rest of option: auto)
------snip

Is this a bug or an error on my part?

I intend to use this scanner for a document management system and expect 
to scan quite a number of non-full-size documents. If x/y auto is indeed 
not available, what would be a good way to automatically crop my scans? 
The included (Mac) Software actually does a decent job so it seems to be 
possible.

Thanks in advance for your answers!

Cheers,

   Manuel