root@linux:/home/essais > scanimage --help -d snapscan:/dev/sg0
Usage: scanimage [OPTION]...

Start image acquisition on a scanner device and write PNM image data to
standard output.

-b, --batch=FORMAT         working in batch mode
    --format=pnm|tiff      file format of output file
-d, --device-name=DEVICE   use a given scanner device (e.g. hp:/dev/scanner)
-h, --help                 display this help message and exit
-L, --list-devices         show available scanner devices
-T, --test                 test backend thoroughly
-v, --verbose              give even more status messages
-V, --version              print version information
    --accept-md5-only      only accept authorization requests using md5

Options specific to device `snapscan:/dev/sg0':
  Scan Mode:
    --resolution auto||50|75|100|150|200|300|600dpi [300]
        Sets the resolution of the scanned image.
    --preview[=(auto|yes|no)] [no]
        Request a preview-quality scan.
    --mode Colour|GreyScale|LineArt [Colour]
        Selects the scan mode (e.g., lineart,monochrome, or color).
    --preview-mode Auto|Colour|GreyScale|LineArt [Auto]
        Select the mode for previews. Greyscale previews usually give the best
        combination of speed and detail.
    --source Flatbed [inactive]
        Selects the scan source (such as a document-feeder).
  Geometry:
    -l 0..216mm (in steps of 1) [0]
        Top-left x position of scan area.
    -t 0..297mm (in steps of 1) [0]
        Top-left y position of scan area.
    -x 0..216mm (in steps of 1) [216]
        Width of scan-area.
    -y 0..297mm (in steps of 1) [297]
        Height of scan-area.
    --predef-window none|6x4|8x10|8.5x11 [none]
        Provides standard scanning areas for photographs, printed pages and
        the like.
  Enhancement:
    --quality-cal[=(yes|no)] [yes]
        Do a quality white-calibration
    --halftoning[=(yes|no)] [inactive]
        Selects whether the acquired image should be halftoned (dithered).
    --halftone-pattern DispersedDot8x8|DispersedDot16x16 [inactive]
        Defines the halftoning (dithering) pattern for scanning halftoned
        images.
    --custom-gamma[=(yes|no)] [no]
        Determines whether a builtin or a custom gamma-table should be used.
    --analog-gamma-bind[=(yes|no)] [no]
        In RGB-mode use same values for each color
    --analog-gamma 0..4 (in steps of 0.0999908) [1.79999]
        Analog gamma-correction
    --analog-gamma-r 0..4 (in steps of 0.0999908) [inactive]
        Analog gamma-correction for red
    --analog-gamma-g 0..4 (in steps of 0.0999908) [inactive]
        Analog gamma-correction for green
    --analog-gamma-b 0..4 (in steps of 0.0999908) [inactive]
        Analog gamma-correction for blue
    --gamma-table 0..255,... (in steps of 1)
        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,... (in steps of 1)
        Gamma-correction table for the red band.
    --green-gamma-table 0..255,... (in steps of 1)
        Gamma-correction table for the green band.
    --blue-gamma-table 0..255,... (in steps of 1)
        Gamma-correction table for the blue band.
    --negative[=(yes|no)] [inactive]
        Swap black and white
    --threshold 0..100% (in steps of 1) [inactive]
        Select minimum-brightness to get a white point
    --brightness -400..400% (in steps of 1) [0]
        Controls the brightness of the acquired image.
    --contrast -100..400% (in steps of 1) [0]
        Controls the contrast of the acquired image.
  Advanced:
    --rgb-lpr 1..50 (in steps of 1) [4]
        Number of scan lines to request in a SCSI read. Changing this
        parameter allows you to tune the speed at which data is read from the
        scanner during scans. If this is set too low, the scanner will have to
        stop periodically in the middle of a scan; if it's set too high,
        X-based frontends may stop responding to X events and your system could
        bog down.
    --gs-lpr 1..50 (in steps of 1) [inactive]
        Number of scan lines to request in a SCSI read. Changing this
        parameter allows you to tune the speed at which data is read from the
        scanner during scans. If this is set too low, the scanner will have to
        stop periodically in the middle of a scan; if it's set too high,
        X-based frontends may stop responding to X events and your system could
        bog down.
  SCSI commands (for debugging):
 
Type ``scanimage --help -d DEVICE'' to get list of all options for DEVICE.
 
List of available devices:
    snapscan:/dev/sg0
root@linux:/home/essais >