Provided by: libsane_1.0.19-6ubuntu1_i386 bug

NAME

       sane-hp - SANE backend for HP ScanJet scanners

DESCRIPTION

       The sane-hp library implements a SANE (Scanner Access Now Easy) backend
       that provides access to HP ScanJet scanners which support SCL  (Scanner
       Control  Language  by HP).  The following scanners are known positively
       to work with this backend:

              Model:         Product id:     Interface:
              ----------     -----------     ----------
              ScanJet Plus   C9195A          HP Parallel Interface Card
              ScanJet IIc    C1750A 3226     SCSI
              ScanJet IIcx   C2500A 3332     SCSI
              ScanJet IIp    C1790A          SCSI
              ScanJet 3C     C2520A 3503     SCSI
              ScanJet 3P     C2570A 3406     SCSI
              ScanJet 4C     C2520A          SCSI
              ScanJet 4P     C1130A 3540     SCSI
              ScanJet 4100C  C6290A          USB
              ScanJet 5P     C5110A          SCSI
              ScanJet 5100C  C5190A          parallel port
              ScanJet 5200C  C7190A 3846     parallel port/USB
              ScanJet 6100C  C2520A 3644     SCSI
              ScanJet 6200C  C6270A 3828     SCSI/USB
              ScanJet 6250C  C6270A 3828     SCSI/USB
              ScanJet 6300C  C7670A          SCSI/USB
              ScanJet 6350C  C7670A          SCSI/USB
              ScanJet 6390C  C7670A          SCSI/USB
              PhotoSmart     C5100A R029,R030,R032    SCSI

       Support for models 5100C/5200C connected to the parallel port  requires
       the            ppSCSI           driver           available           at
       http://cyberelk.net/tim/parport/ppscsi.html     and     http://penguin-
       breeder.org/kernel/download/.

       Support  for  models 5200C/62X0C/63X0C connected to the USB require the
       kernel scanner driver or libusb. See sane-usb(5) for more details.

       The  "hp"  backend  no   longer   supports   OfficeJet   multi-function
       peripherals.   For  these  devices  use  the external "hpoj" backend in
       version 0.90 and later of the "HP OfficeJet Linux driver", available at
       http://hpoj.sourceforge.net

       Because  Hewlett-Packard  does  no longer produce scanners that support
       SCL (beside the OfficeJets), the above list of  supported  scanners  is
       complete.  Other HP scanners are not supported by the "hp" backend, but
       might be supported by another  one.  See  http://www.sane-project.org/.
       You  can  also  watch  the  sane-devel mailing list at http://www.sane-
       project.org/mailing-lists.html.

       More details about  the  hp  backend  can  be  found  on  its  homepage
       http://www.kirchgessner.net/sane.html.

DEVICE NAMES

       This backend expects device names of the form:

              special

       Where  special  is  the  UNIX  path-name  for  the  special device that
       corresponds to the 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/sg2,  for  example.
       If  the special device name contains "usb", "uscanner" or "ugen", it is
       assumed that the scanner is connected by USB.  For the HP ScanJet  Plus
       the  special  device  name  must  be the device that corresponds to the
       parallel interface card that was shipped  with  the  scanner.  That  is
       /dev/hpscan.   A  special  driver  is  required  for  this  card.   See
       ftp://rvs.ctrl-c.liu.se/pub/wingel/hpscan for details. If the link does
       not  work, try ftp://sunsite.unc.edu/pub/Linux/kernel/patches/scanners.

CONFIGURATION

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

       Options  specified  in  front  of the first line that contains a device
       name are defaults for all devices. Options specified below a line  that
       contains  a  device  name  apply  just  to  the most recently mentioned
       device.

       Supported  options  are  connect-scsi,  connect-device,   enable-image-
       buffering, and dumb-read.

       Option  connect-scsi  specifies  that  the  scanner is connected to the
       system by SCSI.  Input/output is performed using SCSI-commands. This is
       the  default.   But if your SCSI device name contains "usb", "uscanner"
       or "ugen", option connect-scsi  must  be  specified.  Otherwise  it  is
       assumed that the scanner is connected by USB.

       Option  connect-device  specifies  that the scanner is connected to the
       system  by   a   special   device.   Input/output   is   performed   by
       read()/write()-operations  on  the device. This option must be used for
       HP ScanJet Plus or scanners connected to USB which are accessed through
       a named device (e.g. /dev/usb/scanner0).  For device names that contain
       "usb", "uscanner" or "ugen", it is  not  necessary  to  specify  option
       connect-device.

       Option enable-image-buffering stores the scanned image in memory before
       passing it to the frontend. Could be used in case  of  forward/backward
       moving scanner lamp.

       Option dumb-read can be used to work around problems with "Error during
       device  I/O".  These  problems  may  occur  with  certain   SCSI-to-USB
       converters  or  Buslogic SCSI cards.  The option should not be used for
       SCSI  devices  which  are  working  correctly.   Otherwise  startup  of
       frontends and changing parameters might be slower.

       A sample configuration file is shown below:

              /dev/scanner
              # this is a comment
              /dev/hpscan
                option connect-device

       /dev/scanner  is typically a symlink to the actual SCSI scanner device.

FILES

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

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

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

       $HOME/.sane/calib-hp:<device>.dat
              Calibration  data  for  HP  PhotoSmart  PhotoScanner   that   is
              retrieved  from  the  scanner  after  calibration.  The  data is
              uploaded to the scanner at start of the  backend  if  it  is  in
              media  mode  ’print  media’  or  if the media mode is changed to
              ’print media’.

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_HP
              If  the  library  was  compiled with debug support enabled, this
              environment variable controls the debug level for this  backend.
              E.g.,  a  value  of 128 requests all debug output to be printed.
              Smaller levels reduce verbosity.

       SANE_HOME_HP
              Only  used  for  OS/2  and  along  with  use  of  HP  PhotoSmart
              PhotoScanner.   Must be set to the directory where the directory
              .sane is located.  Is used to  save  and  read  the  calibration
              file.

       SANE_HP_KEEPOPEN_SCSI

       SANE_HP_KEEPOPEN_USB

       SANE_HP_KEEPOPEN_DEVICE
              For each type of connection (connect-scsi, connect-usb, connect-
              device) it can be specified if  the  connection  to  the  device
              should be kept open ("1") or not ("0").  Usually the connections
              are closed after an operation is performed.  Keeping  connection
              open  to SCSI-devices can result in errors during device IO when
              the scanner has not been used for some time.  By  default,  USB-
              connections are kept open. Other connections are closed.

       SANE_HP_RDREDO
              Specifies  number of retries for read operation before returning
              an EOF error.  Only supported for non-SCSI devices.  Default:  1
              retry. Time between retries is 0.1 seconds.

BUGS

       HP PhotoSmart PhotoScanner
              In  media  mode  ’slide’  and  ’negative’,  scan resolutions are
              rounded to multiple of 300 dpi. The scanner does not  scale  the
              data correctly on other resolutions. Some newer models (firmware
              code  R030   and   later)   do   not   support   adjustment   of
              contrast/intensity   level  and  tone  map.   The  backend  will
              simulate this by software, but only for gray and 24 bit color.

       Automatic Document Feeder (ADF)
              For use of the ADF with xscanimage(1), first place paper in  the
              ADF  and  then change option scan source to ’ADF’. Press ’change
              document’ to load a sheet. Then press ’scan’ to  start  a  scan.
              Maybe it is sufficient to press ’scan’ without ’change document’
              for repeated scans.  The  use  of  the  preview  window  is  not
              recommended when working with the ADF.  Setting a window to scan
              from ADF is not supported with xscanimage(1).  Try xsane(1).

       Immediate actions
              Some  actions  in  xscanimage(1)  (i.e.  unload,  select  media,
              calibrate)  have  an  immediate  effect  on  the scanner without
              starting a scan.  These options can not be used with  scanimage.

TODO

       HP PhotoSmart PhotoScanner
              PhotoScanners with firmware release R030 and up have no firmware
              support for  contrast/brightness/gamma  table.  In  the  current
              backend   this  is  simulated  by  software  on  24  bits  data.
              Simulation on 30 bits should give better results.

       Data widths greater than 8 bits
              Custom gamma table does not work.

       Parallel scanner support
              Beside the  ScanJet  Plus  which  came  with  its  own  parallel
              interface  card,  currently  only the HP ScanJet 5100C/5200C are
              supported.  These scanners are using  an  internal  parallel-to-
              SCSI  converter  which  is  supported  by the ppSCSI-driver (see
              above).

SEE ALSO

       sane(7), sane-scsi(5), sane-usb(5)

AUTHOR

       The sane-hp backend was written by Geoffrey T. Dairiki.  HP  PhotoSmart
       PhotoScanner support by Peter Kirchgessner.