sane-rts8891(5)           (8 Dec 2008)            sane-rts8891(5)

     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(1)
          or through GUI elements in xscanimage(1) or xsane(1).

          If you notice 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 resolu-
               tions for the specified option value:

                 Value   Hor. Resolution  Vert. Resolution
                 -----   ---------------  -------------------

     Page 1                       Plan 9             (printed 5/26/22)

     sane-rts8891(5)           (8 Dec 2008)            sane-rts8891(5)

                 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 mul-
               tiple frontends at the same time.

          modelnumber
               is used to force the reported model by the backend and
               is only useful 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/x86_64-linux-gnu/sane/libsane-rts8891.a
               The static library implementing this backend.

     Page 2                       Plan 9             (printed 5/26/22)

     sane-rts8891(5)           (8 Dec 2008)            sane-rts8891(5)

          /usr/lib/x86_64-linux-gnu/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 control 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 sup-
          ported than others. At least 75 dpi mode is working for any
          model. Sharing the scanner between several frontends at the
          same time (allowsharing option) may not work on some USB
          controllers.

          XPA is not (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 developed by St['e]phane 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.

     Page 3                       Plan 9             (printed 5/26/22)