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@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/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
              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)
