Provided by: libsane-common_1.0.22-7ubuntu1_amd64 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/arch_triplet/sane/libsane-hp.a
              The static library implementing this backend.

       /usr/lib/arch_triplet/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.

                                           13 Jul 2008                                 sane-hp(5)