Provided by: libsane_1.0.17-1ubuntu4_i386 bug

NAME

       sane-apple - SANE backend for Apple flatbed scanners

DESCRIPTION

       The  sane-apple  library  implements  a  SANE (Scanner Access Now Easy)
       backend that provides access to Apple flatbed scanners. At present, the
       following scanners are supported from this backend:

       --------------- ----- ------------------ ------
       AppleScanner    4bit  16 Shades of Gray
       OneScanner      8bit  256 Shades of Gray
       ColorOneScanner 24bit RGB color          3-pass

       If  you own a Apple scanner other than the ones listed above that works
       with this backend, please let us know by sending  the  scanner’s  model
       name,     SCSI     id,     and     firmware     revision    to    sane-
       devel@lists.alioth.debian.org.           See           http://www.sane-
       project.org/mailing-lists.html for details on how to subscribe to sane-
       devel.

DEVICE NAMES

       This backend expects device names of the form:

              special

       Where special is either the  path-name  for  the  special  device  that
       corresponds  to  a  SCSI scanner. For SCSI scanners, the special device
       name must be a generic SCSI device or  a  symlink  to  such  a  device.
       Under  Linux,  such  a  device  name could be /dev/sga or /dev/sge, for
       example.  See sane-scsi(5) for details.

CONFIGURATION

       The contents of the apple.conf file is a list  of  options  and  device
       names  that  correspond  to  Apple  scanners.   Empty  lines  and lines
       starting with a hash mark (#) are ignored.  See sane-scsi(5) on details
       of what constitutes a valid device name.

       Options  come  in  two  flavors:  global  and  positional ones.  Global
       options apply to all devices managed by the backend whereas  positional
       options  apply  just  to the most recently mentioned device.  Note that
       this means that the order in which the options appear matters!

SCSI ADAPTER TIPS

       SCSI scanners  are  typically  delivered  with  an  ISA  SCSI  adapter.
       Unfortunately, that adapter is not worth much since it is not interrupt
       driven.  It is (sometimes) possible to get the supplied card  to  work,
       but  without  interrupt  line,  scanning  will  put so much load on the
       system, that it becomes almost unusable for other tasks.

FILES

       /etc/sane.d/apple.conf
              The  backend  configuration  file  (see  also   description   of
              SANE_CONFIG_DIR below).

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

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

ENVIRONMENT

       SANE_CONFIG_DIR
              This environment variable specifies the list of directories that
              may contain the configuration file.  Under UNIX, the directories
              are separated by a colon (‘:’), under OS/2, they  are  separated
              by  a  semi-colon  (‘;’).   If  this  variable  is  not set, the
              configuration file  is  searched  in  two  default  directories:
              first,   the   current  working  directory  (".")  and  then  in
              /etc/sane.d.  If the value of the environment variable ends with
              the  directory separator character, then the default directories
              are searched after the explicitly  specified  directories.   For
              example,  setting SANE_CONFIG_DIR to "/tmp/config:" would result
              in  directories  "tmp/config",  ".",  and  "/etc/sane.d"   being
              searched (in this order).

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

CURRENT STATUS

       The apple backend is now in version 0.3 (Tue Jul 21 1998). Since I only
       have   the   AppleScanner   and   not  the  other  models  (OneScanner,
       ColorOneScanner)  I  can  only  develop/test   for   the   AppleScanner
       effectively.   However with this release I almost complete the gui part
       of all  scanners.   Most  of  the  functionality  is  there.  At  least
       OneScanner should scan at the AppleScanner’s compatible modes (LineArt,
       HalfTone, Gray16). My personal belief is that with a  slight  touch  of
       debugging  the OneScanner could be actually usable. The ColorOneScanner
       needs more work. AppleScanner is of course almost fully supported.

MISSING FUNCTIONALITY

       Currently all 3 models are lacking upload/dowload support.

       AppleScanner
              Cannot up/download a halftone pattern.

       OneScanner
              Cannot up/download halftone pattern and calibration vector.

       ColorOneScanner
              Cannot up/download halftone pattern, calibration vectors, custom
              Color  Correction Table (CCT) and of course custom gamma tables.

       Park/UnPark (OneScanner, ColorOneScanner)

       The above functionalities are not only missing because I don’t actually
       have  the  hardware  to experiment on it. Another reason is the lack of
       understanding of how SANE API could  provide  enaugh  means  to  me  to
       actually describe other array types than the gamma one.

UNSUPPORTED FEATURES

       The  following  "features"  will  never  be supported. At least as I am
       maintaining the sane-apple backend.

       NoHome (AppleScanner)
              The scanner lamp stays on  and  the  carriage  assembly  remains
              where it stops at the end of the scan. After two minutes, if the
              scanner does not receive another SCAN command the lamp goes  off
              and the carriage returns to the home position.

       Compression (AppleScanner)
              The  Scanner  can  compress  data  with  CCITT  Group  III,  one
              dimensional algorithm (fax), and the Skip White Line  algorithm.

       Multiple Windows (AppleScanner)
              AppleScanner  may  support  multiple windows. It would be a cool
              feature and a challenge for me to code it if you could  intermix
              different  options  for different windows (scan areas). This way
              you could scan a document in LineArt mode but the figures in  it
              on  Gray  and  in a different resolution.  Unfortunately this is
              impossible.

       Scan Direction (OneScanner)
              It controls the scan direction. (?)

       Status/Reset Button (OneScanner)
              This option controls the status  of  the  button  in  OneScanner
              model. You can also reset the button status by software.

BUGS

       The bugs in a sane backend are divided in two classes. We have GUI bugs
       and scanner specific bugs.

       We know we have a GUI bug when a parameter is  not  showing  up  itself
       when it should (active) or vice versa. To find out which parameters are
       active accross various Apple modes and models  from  the  documentation
       ftp://ftpdev.info.apple.com/devworld/Technical_Documentation/Peripherals_Documentation/
       is an interesting exercise. I may missed some dependancies. For example
       for  the  threshold parameter the Apple Scanners Programming guide says
       nothing. I had to assume that is valid only in LineArt mode.

       Scanner specific bugs are mostly due to mandatory round offs  in  order
       to  scan.  In  the documentation in some place states that the width of
       the scan area should be a byte multiple. In an other  place  says  that
       the  width  of  the  scan  area  should  be  an  even byte multiple. Go
       figure...

       Other source of bugs are due to scsi communcation,  scsi  connects  and
       disconnects.  However  the  classical  bugs are still there. So you may
       encouter buffer overruns, null pointers, memory corruption and SANE API
       violations.

       SIGSEGV on SliceBars
              When you try to modify the scan area from the slice bar you have
              a nice little cute core dump. I don’t know why.  If  you  select
              the  scan  are  from  the  preview window, or by hand typing the
              numbers everything is fine. The  SIGSEGV  happens  deep  in  gtk
              library (gdk). I really cannot debug it.

       Options too much
              It  is  possible,  especially  for the ColorOneScanner, that the
              backend’s options panel to exceed from your screen.  It  happens
              with  mine  and I am running at 1024x768 my X Server. What can I
              say? Try smaller fonts in the X server, or virtual screens.

       Weird SCSI behaviour
              I am quoting David Myers Here...

              >> OS: FreeBSD 2.2.6
              >> CC: egcs-1.02
              Just wanted to follow up on this...  I recently changed my  SCSI
              card  from  the  Adaptec  2940UW  to  a dual-channel Symbios 786
              chipset.  When I started up SANE with your driver, I managed  to
              scan line art drawings okay, but Gray16 scans led to a stream of
              SCSI error messages on the console, ultimately  hanging  with  a
              message  saying the scanner wasn’t releasing the SCSI bus.  This
              may be that the Symbios  is  simply  less  tolerant  of  ancient
              hardware, or may be bugs in your driver or in SANE itself...

DEBUG

       If  you  encounter  a  GUI  bug  please  set  the  environment variable
       SANE_DEBUG_APPLE to 255 and rerun the excact sequence of keystrokes and
       menu  selections  to  reproduce  it. Then send me a report with the log
       attached.

       It would be very helpfull if you have handy an Apple machine (I am  not
       sure  how  Mackintoshs  are  spelled)  with  the  AppleScanners  driver
       installed and check what option are grayed out (inactive) in what modes
       and report back to me.

       If  you  want  to  offer  some help but you don’t have a scanner or you
       don’t have the model you would like to offer some help, or  you  are  a
       sane  developer  and  you  just  want  to  take a look at how the apple
       backend looks like. Goto to apple.h and #define the  NEUTRALIZE_BACKEND
       macro.  You can select the scanner model through the APPLE_MODEL_SELECT
       macro. Available options are APPLESCANNER, ONESCANNER, COLORONESCANNER.

       If  you  encounter  a SCSI bus error or trimmed and/or displaced images
       please also set the environment variable SANE_DEBUG_SANEI_SCSI  to  255
       before sendme the report.

TODO

       Non Blocking Support
              Make  sane-apple  a  non  blocking backend. Properly support for
              sane_set_io_mode and sane_get_select_fd

       Scan   Make scan possible for all models in all supported modes.

       Missing Functionality

SEE ALSO

       sane(7), sane-scsi(5)

AUTHOR

       The sane-apple backend was written not entirely from scratch  by  Milon
       Firikis.  It is mostly based on the mustek backend from David Mosberger
       and Andreas Czechanowski