Provided by: libsane-common_1.0.27-3.2ubuntu3_all 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

       @CONFIGDIR@/apple.conf
              The backend configuration file (see also description of SANE_CONFIG_DIR below).

       @LIBDIR@/libsane-apple.a
              The static library implementing this backend.

       @LIBDIR@/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  "@CONFIGDIR@"
              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)
              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 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.

       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 mustek backend from David Mosberger and Andreas Czechanowski

@PACKAGEVERSION@                           11 Jul 2008                              sane-apple(5)