I also have an avision-based scanner (Xerox DocuMate 510), and encountered the reported issue with the version of sane-utils in wheezy.
I downloaded the later version of the package source from unstable, built the package, and verified it resolved the problem. kbare@musicality:~$ scanimage -L device `v4l:/dev/video0' is a Noname BT878 video (Hauppauge (bt878)) virtual device device `avision:libusb:002:012' is a Xerox DocuMate510-G flatbed scanner kbare@musicality:~$ scanimage -d avision --help Usage: scanimage [OPTION]... Start image acquisition on a scanner device and write image data to standard output. Parameters are separated by a blank from single-character options (e.g. -d epson) and by a "=" from multi-character options (e.g. --device-name=epson). -d, --device-name=DEVICE use a given scanner device (e.g. hp:/dev/scanner) --format=pnm|tiff file format of output file -i, --icc-profile=PROFILE include this ICC profile into TIFF file -L, --list-devices show available scanner devices -f, --formatted-device-list=FORMAT similar to -L, but the FORMAT of the output can be specified: %d (device name), %v (vendor), %m (model), %t (type), %i (index number), and %n (newline) -b, --batch[=FORMAT] working in batch mode, FORMAT is `out%d.pnm' or `out%d.tif' by default depending on --format --batch-start=# page number to start naming files with --batch-count=# how many pages to scan in batch mode --batch-increment=# increase page number in filename by # --batch-double increment page number by two, same as --batch-increment=2 --batch-prompt ask for pressing a key before scanning a page --accept-md5-only only accept authorization requests using md5 -p, --progress print progress messages -n, --dont-scan only set options, don't actually scan -T, --test test backend thoroughly -A, --all-options list all available backend options -h, --help display this help message and exit -v, --verbose give even more status messages -B, --buffer-size=# change input buffer size (in kB, default 32) -V, --version print version information Options specific to device `avision': Scan mode: --mode Lineart|Dithered|Gray|Color [Color] Selects the scan mode (e.g., lineart, monochrome, or color). --resolution 75..600dpi (in steps of 1) [150] Sets the resolution of the scanned image. --speed 0..4 (in steps of 1) [0] Determines the speed at which the scan proceeds. --preview[=(yes|no)] [no] Request a preview-quality scan. --source Normal|ADF Front [Normal] Selects the scan source (such as a document-feeder). Geometry: -l 0..216mm [0] Top-left x position of scan area. -t 0..297mm [0] Top-left y position of scan area. -x 0..216mm [216] Width of scan-area. -y 0..297mm [297] Height of scan-area. --overscan-top 0..4mm [inactive] The top overscan controls the additional area to scan before the paper is detected. --overscan-bottom 0..4mm [inactive] The bottom overscan controls the additional area to scan after the paper end is detected. --background-lines 0..50pel [inactive] The background raster controls the additional background lines to scan before the paper is feed through the scanner. Enhancement: --brightness -100..100% (in steps of 1) [0] Controls the brightness of the acquired image. --contrast -100..100% (in steps of 1) [0] Controls the contrast of the acquired image. --quality-scan[=(yes|no)] [yes] Turn on quality scanning (slower but better). --quality-cal[=(yes|no)] [yes] Do a quality white-calibration --gamma-table 0..255,... [inactive] Gamma-correction table. In color mode this option equally affects the red, green, and blue channels simultaneously (i.e., it is an intensity gamma table). --red-gamma-table 0..255,... Gamma-correction table for the red band. --green-gamma-table 0..255,... Gamma-correction table for the green band. --blue-gamma-table 0..255,... Gamma-correction table for the blue band. --exposure 0..1000% (in steps of 1) [inactive] Manual exposure adjustment. --infra-red[=(yes|no)] [inactive] Enable infra-red scan mode. --multi-sample[=(yes|no)] [inactive] Enable multi-sample scan mode. Scan mode: --frame 0..0 [inactive] Selects the number of the frame to scan --power-save-time <int> [15] Allows control of the scanner's power save timer, dimming or turning off the light. --paper-length[=(yes|no)] [inactive] Newer scanners can utilize this paper length to detect double feeds. However some others (DM152) can get confused during media flush if it is set. --flip-page[=(auto|yes|no)] [inactive] Tells page-flipping document scanners to flip the paper back to its original orientation before dropping it in the output tray. Turning this off might make scanning a little faster if you don't care about manually flipping the pages afterwards. Type ``scanimage --help -d DEVICE'' to get list of all options for DEVICE. List of available devices: v4l:/dev/video0 avision:libusb:002:012 kbare@musicality:~$ dpkg -l sane-utils Desired=Unknown/Install/Remove/Purge/Hold | Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend |/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad) ||/ Name Version Architecture Description +++-==============-============-============-================================= ii sane-utils 1.0.23-3 amd64 API library for scanners -- utili --Keith