sane-apple.5



sane-apple(5)            SANE Scanner Access Now Easy            sane-apple(5)


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@alioth-lists.de-
       bian.net.  See http://www.sane-project.org/mailing-lists.html  for  de-
       tails 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 cor-
       responds 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 corre-
       spond 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  op-
       tions  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.  Unfor-
       tunately, 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

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

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

       /usr/local/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  search-
              ing  the  current  working  directory  (".")  and  then /usr/lo-
              cal/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
              /usr/local/etc/sane.d being searched (in that order).

       SANE_DEBUG_APPLE
              Controls the debug level.  A value of 255 prints all debug  out-
              put.   Smaller values reduce verbosity.  Requires a library com-
              piled 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, ColorOneS-
       canner) I can only develop/test for the AppleScanner effectively.  How-
       ever 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. AppleS-
       canner 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,  cus-
              tom Color Correction Tables (CCT) and of course custom gamma ta-
              bles.

       Park/UnPark (OneScanner, ColorOneScanner)
              Some capabilities are missing.

       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 dimen-
              sional 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 dif-
              ferent 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  im-
              possible.

       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://ft-
       pdev.info.apple.com/devworld/Technical_Documentation/Peripherals_Docu-
       mentation/ is an interesting exercise. I may have missed some dependen-
       cies. For example of the threshold parameter the  Apple  Scanners  Pro-
       gramming  Guide  says nothing. I had to assume it is valid only in Lin-
       eArt 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 en-
       counter  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 num-
              bers 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 hard-
              ware, 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 at-
       tached.

       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 de-
       veloper 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. Avail-
       able options are APPLESCANNER, ONESCANNER, and 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.

       Add other 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 sane-mustek(5)  backend  from  David
       Mosberger and Andreas Czechanowski

                                  11 Jul 2008                    sane-apple(5)

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