Provided by: libsane_1.0.20-4ubuntu3_i386 bug

NAME

       sane-rts8891 - SANE backend for rts8891 based scanners

DESCRIPTION

       The  sane-rts8891  library  implements a SANE (Scanner Access Now Easy)
       backend that provides access to scanners based on the rts8891 ASIC.

       The scanners that work with this backend are:

                 Vendor Model           status
              ----------------------  -----------
                Umax Astra 4400       untested
                Umax Astra 4450       untested
                HP scanjet 4000c      good
                HP scanjet 4470c      good

       The options the backend supports can either be selected through command
       line  options  to  programs  like  scanimage or through GUI elements in
       xscanimage or xsane.

       If you  have  any  strange  behavior,  please  report  to  the  backend
       maintainer or to the SANE mailing list.

       Valid command line options and their syntax can be listed by using
              scanimage --help -d rts8891

       Scan Mode Options

       --mode selects the basic mode of operation of the scanner valid choices
              are R Color , Gray and Lineart The default mode  is  Color.  The
              Lineart  mode  is  black and white only (1 bit).  Grayscale will
              produce 256 levels of gray (8 bits). Color mode allows for  over
              16  million  different  colors  produced  from  24 bits of color
              information.

       --resolution
              selects the resolution for a scan. The horizontal  and  vertical
              resolutions  are set by the value of this option. The scanner is
              capable of the following resolutions for  the  specified  option
              value:

                Value   Hor. Resolution  Vert. Resolution
                -----   ---------------  -------------------
                75      75dpi            75dpi
                150     150dpi           150dpi
                300     300dpi           300dpi
                600     600dpi           600dpi
                1200    1200dpi          1200dpi

       --preview
              requests a preview scan. The resolution used for that scan is 75
              dpi and the scan area and the scan mode are as specified through
              their  options,  or  the  default  if not specified. The default
              value for preview mode is "no".

       --threshold
              selects the   minimum-brightness  to  get  a  white  point.  The
              threshold is only used with Lineart mode scans.  It is specified
              as a percentage in the range  0..100%  (in  steps  of  1).   The
              default value of the threshold option is 50.

CONFIGURATION FILE

       The configuration file /etc/sane.d/rts8891.conf contains the usb device
       ids  of  supported  scanners  (eg  usb  0x043d  0x007c)   and   scanner
       configuration options.  Empty lines and lines starting with a hash mark
       (#) are ignored.

       The options supported are allowsharing , modelnumber

       Option

       allowsharing enables or not the sharing of the scanner between multiple
       frontends at the same time.

       modelnumber  is  used to force the reported model by the backend and is
       only usefull in the case of a scanner which NVRAM has been erased.
              0 to report a HP4470c.
              1 to report a HP4400c.
              2 to report an Astra 4400.

FILES

       /usr/lib/sane/libsane-rts8891.a
              The static library implementing this backend.

       /usr/lib/sane/libsane-rts8891.so
              The shared library implementing this backend (present on systems
              that support dynamic loading).

ENVIRONMENT

       SANE_DEBUG_RTS8891 SANE_DEBUG_RTS8891_LOW SANE_DEBUG_RTS88XX_LIB
              If  the  library  was compiled with debug support enabled, these
              environment variables controls the debug level for this backend.
              E.g.,  a  value  of 255 requests all debug output to be printed.
              Smaller levels reduce verbosity.

LIMITATIONS

       Scanners of the same model exist with different sensors, due to lack of
       data  (ie  USB  logs) some sensors are better supported than others. At
       least 75 dpi mode is working for  any  model.  Sharing  the  a  scanner
       between  several  frontends  at the same time (allowsharing option) may
       not work on some USB controllers.

       XPA is no (yet) supported.

BUGS

       No bugs currently known.

SEE ALSO

       sane-scsi(5), scanimage(1), xscanimage(1), xsane(1), sane(7)

AUTHOR

       This backend has been developped by St├ęphane Voltz.
              http://stef.dev.free.fr/sane/rts8891

CREDITS

       Many thanks go to:
              Laurent Fournier who donated me a HP4470c.  Vladimir Sysoev  and
              "TheUnruly  Squash"  for  the  time  they  spent  recording  USB
              activity and testing the experimental version on HP4400  models.

                                  8 Dec 2008                   sane-rts8891(5)