Provided by: libsane-common_1.0.27-1~experimental3ubuntu2.4_all 
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 @CONFIGDIR@/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 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
@LIBDIR@/libsane-rts8891.a
The static library implementing this backend.
@LIBDIR@/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 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 developed by Stéphane 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.
@PACKAGEVERSION@ 8 Dec 2008 sane-rts8891(5)