Provided by: libsane_1.0.21-2ubuntu2_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 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 an 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 is  list  of  directories  where  SANE
              looks  for  the  configuration file.  Under UNIX directory names
              are separated by a colon  (‘:’),  under  OS/2  by  a  semi-colon
              (‘;’).    If  SANE_CONFIG_DIR  is  not  set,  SANE  defaults  to
              searching  the  current  working  directory   (".")   and   then
              /etc/sane.d.   If  the  value  of $SANE_CONFIG_DIR ends with the
              separator character, the default directories are searched  after
              the  directory  list.   For  example, setting SANE_CONFIG_DIR to
              "/tmp/config:" would result in  directories  "tmp/config",  ".",
              and "/etc/sane.d" being searched (in that order).

       SANE_DEBUG_APPLE
              Controls  the  debug  level.   A  value  of 255 prints all debug
              output.  Smaller values reduce verbosity.   Requires  a  library
              compiled with debug support.

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 completed 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 three models lack upload/download support.

       AppleScanner
              Cannot up/download a halftone pattern.

       OneScanner
              Cannot up/download halftone patterns or calibration vectors.

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

       Park/UnPark (OneScanner, ColorOneScanner)

       The above functionalities are missing because I don’t have the hardware
       to experiment on.  Another reason is my lack of understanding as to how
       or  if  the  SANE  API provide means to describe any array type besides
       gamma.

UNSUPPORTED FEATURES

       The following "features" will never be  supported,  at  least  while  I
       maintain 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  if  it  could  intermix
              different  options  for different windows (scan areas). This way
              it could scan a document in LineArt mode but the figures  in  it
              in  Gray  and  at 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 on the  OneScanner
              model. You can also reset the button status by software.

BUGS

       SANE  backend  bugs  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  when  it
       should  (active) or vice versa. Finding out which parameters are active
       across  various  Apple  modes  and  models   from   the   documentation
       ftp://ftpdev.info.apple.com/devworld/Technical_Documentation/Peripherals_Documentation/
       is an interesting exercise. I may have missed  some  dependencies.  For
       example of the threshold parameter the Apple Scanners Programming Guide
       says nothing. I had to assume it is valid only in LineArt mode.

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

       Other  sources of bugs are due to scsi communication, scsi connects and
       disconnects. However the classical bugs are still  there.  So  you  may
       encounter  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 area 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,  for  the
              backend’s options panel to extend beyond your screen. It happens
              with mine and I am running my X Server at 1024x768. 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  environmental  variable
       SANE_DEBUG_APPLE  to 255 and rerun the exact sequence of keystrokes and
       menu selections to reproduce it. Then send me a  report  with  the  log
       attached.

       If you have an Apple Macintosh with the AppleScanners driver installed,
       reporting to me which options are grayed out (inactive) in  what  modes
       would be very helpful.

       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 help with, 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 set the environment variable SANE_DEBUG_SANEI_SCSI to 255 before
       sending me the report.

TODO

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

       Scan   Make scanning 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

                                  11 Jul 2008                    sane-apple(5)