sane-rts8891(5)          SANE Scanner Access Now Easy          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 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/local/lib/sane/libsane-rts8891.a
              The static library implementing this backend.

       /usr/local/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 Stephane 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)
