That 'auto' string is put there by scanimage, when it finds an option with the SANE_CAP_AUTOMATIC capability set. Unfortunately, scanimage has some special handling for the x/y/t/l parameters. It appears that -l and -t will properly parse the 'auto' string, but -x and -y will not. This is a bug in scanimage, specifically in parse_vector().
If the pixma devices are unable to detect paper width in hardware, the SANE_CAP_AUTOMATIC cap should be removed from those options. Or, the pixma backend could be extended to use sanei_magic library, which other backends use to add features like deskew and crop. Outside of modifying sane-backends, you might look at the program unpaper for post-processing the images. allan On Thu, Apr 27, 2017 at 5:05 PM, Manuel Reiter <man...@reiter.pm> wrote: > Nobody? I found this old discussion which seems to suggest the pixma devices > don't support auto-detection: > > http://lists.alioth.debian.org/pipermail/sane-devel/2009-December/025674.html > > If that's indeed the case, may I suggest updating the pixma backend so that > it doesn't advertise capabilities that don't exist? > > Also, I'd still appreciate suggestion for a scriptable approach to achieve > this functionality. > > Thanks, > > Manuel > > Am 11.04.2017 um 16:44 schrieb 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@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 >> >> -- >> sane-devel mailing list: sane-devel@lists.alioth.debian.org >> http://lists.alioth.debian.org/cgi-bin/mailman/listinfo/sane-devel >> Unsubscribe: Send mail with subject "unsubscribe your_password" >> to sane-devel-requ...@lists.alioth.debian.org > > > -- > sane-devel mailing list: sane-devel@lists.alioth.debian.org > http://lists.alioth.debian.org/cgi-bin/mailman/listinfo/sane-devel > Unsubscribe: Send mail with subject "unsubscribe your_password" > to sane-devel-requ...@lists.alioth.debian.org -- "well, I stand up next to a mountain- and I chop it down with the edge of my hand" -- sane-devel mailing list: sane-devel@lists.alioth.debian.org http://lists.alioth.debian.org/cgi-bin/mailman/listinfo/sane-devel Unsubscribe: Send mail with subject "unsubscribe your_password" to sane-devel-requ...@lists.alioth.debian.org