sane-bh.5



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


NAME

       sane-bh  -  SANE  backend  for  Bell+Howell Copiscan II series document
       scanners


DESCRIPTION

       The sane-bh library implements a SANE (Scanner Access Now Easy) backend
       that  provides  access to Bell+Howell Copiscan II series document scan-
       ners.  The Copiscan II 6338 has been the  primary  scanner  model  used
       during development and testing, but since the programming interface for
       the entire series is consistent the backend should work for the follow-
       ing scanner models:

              COPISCAN II 6338 Duplex Scanner with ACE
              COPISCAN II 2135 Simplex Scanner
              COPISCAN II 2137(A) Simplex Scanner (with ACE)
              COPISCAN II 2138A Simplex Scanner with ACE
              COPISCAN II 3238 Simplex Scanner
              COPISCAN II 3338(A) Simplex Scanner (with ACE)

       If  you  have  a  Bell+Howell scanner and are able to test it with this
       backend, please  contact  sane-devel@alioth-lists.debian.net  with  the
       model    number    and    testing    results.    Have    a    look   at
       http://www.sane-project.org/mailing-lists.html concerning  subscription
       to sane-devel. Additionally, the author is curious as to the likelihood
       of using this backend with the newer 4000 and 8000 series scanners.  If
       you have such a beast, please let me know.

       The  Bell+Howell  Copiscan II series document scanners are high volume,
       high throughput scanners designed for document  scanning  applications.
       As  such, they are lineart/grayscale scanners supporting a fixed number
       of fairly low resolutions (e.g. 200/240/300dpi).  However, they do have
       a number of interesting and useful features suited to needs of document
       imaging applications.  This backend attempts  to  support  as  many  of
       these features as possible.

       The  main  technical reference used in writing this backend is the Bell
       and Howell Copiscan II Remote SCSI Controller (RSC) OEM Technical  Man-
       ual  Version 1.5.  The Linux SCSI programming HOWTO, the SANE API docu-
       mentation, and SANE source code were also extremely valuable resources.

       The latest backend release, additional information  and  helpful  hints
       are available from the backend homepage:
              http://www.martoneconsulting.com/sane-bh.html


DEVICE NAMES

       This backend expects device names of the form:

              special

       Where  special is 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 takes a format such as /dev/sga or /dev/sg0,  for  example.
       See sane-scsi(5) for details.


OPTIONS

       Scan Mode Options:

       --preview[=(yes|no)] [no]
              Request  a preview-quality scan.  When preview is set to yes im-
              age compression is disabled and the  image  is  delivered  in  a
              SANE_FRAME_GRAY frame.

       --mode lineart|halftone [lineart]
              Selects the scan mode (e.g., lineart,monochrome, or color).

       --resolution 200|240|300dpi [200]
              Sets  the  resolution  of the scanned image.  Each scanner model
              supports a list of standard resolutions; only these  resolutions
              can be used.

       --compression none|g31d|g32d|g42d [none]
              Sets  the  compression mode of the scanner.  Determines the type
              of data returned from the scanner.  Values are:

              none - uncompressed data - delivered in a SANE_FRAME_GRAY frame
              g31d  -  CCITT  G3  1  dimension   (MH)   -   delivered   in   a
              SANE_FRAME_G31D frame
              g32d  -  CCITT  G3  2  dimensions  (MR,  K=4)  -  delivered in a
              SANE_FRAME_G32D frame
              g42d - CCITT G4 (MMR) - delivered in a SANE_FRAME_G42D frame

              NOTE: The use of g31d, g32d, and g42d compression values  causes
              the  backend to generate optional frame formats which may not be
              supported by all SANE frontends.

       Geometry Options:

       --autoborder[=(yes|no)] [yes]
              Enable/Disable automatic image border detection.  When  enabled,
              the  RSC  unit automatically detects the image area and sets the
              window geometry to match.

       --paper-size Custom|Letter|Legal|A3|A4|A5|A6|B4|B5 [Custom]
              Specify the scan window geometry by specifying the paper size of
              the documents to be scanned.

       --tl-x 0..297.18mm [0]
              Top-left x position of scan area.

       --tl-y 0..431.8mm [0]
              Top-left y position of scan area.

       --br-x 0..297.18mm [297.18]
              Bottom-right x position of scan area.

       --br-y 0..431.8mm [431.8]
              Bottom-right y position of scan area.

       Feeder Options:

       --source Automatic Document Feeder|Manual Feed Tray [Automatic Document
       Feeder]
              Selects the scan source (such as a document feeder).   This  op-
              tion   is   provided   to   allow   multiple  image  scans  with
              xsane(1);ithasnootherpurpose.

       --batch[=(yes|no)] [no]
              Enable/disable batch mode scanning.  Batch mode allows  scanning
              at  maximum  throughput  by buffering within the RSC unit.  This
              option is recommended when performing multiple pages scans until
              the feeder is emptied.

       --duplex[=(yes|no)] [no]
              Enable duplex (dual-sided) scanning.  The scanner takes an image
              of each side of the document during a single  pass  through  the
              scanner.  The front page is delivered followed by the back page.
              Most options, such as compression, affect  both  the  front  and
              back pages.

       --timeout-adf 0..255 [0]
              Sets  the  timeout  in seconds for the automatic document feeder
              (ADF).  The value 0 specifies the hardware default  value  which
              varies based on the scanner model.

       --timeout-manual 0..255 [0]
              Sets  the  timeout  in  seconds  for semi-automatic feeder.  The
              value 0 specifies the hardware default value which varies  based
              on the scanner model.

       --check-adf[=(yes|no)] [no]
              Check  ADF  Status prior to starting scan using the OBJECT POSI-
              TION command.  Note that  this  feature  requires  RSC  firmware
              level 1.5 or higher and dip switch 4 must be in the on position.
              NOTE: This option has not been tested extensively and  may  pro-
              duce undesirable results.

       Enhancement:

       --control-panel[=(yes|no)] [yes]
              Enables the scanner's control panel for selecting image enhance-
              ment parameters.  When the option is set to no the following op-
              tions  are used to control image enhancement.  See the Bell+How-
              ell scanner users' guide for complete information on  ACE  func-
              tionality.

       --ace-function -4..4 [3]
              Specify the Automatic Contrast Enhancement (ACE) Function.

       --ace-sensitivity 0..9 [5]
              Specify the Automatic Contrast Enhancement (ACE) Sensitivity.

       --brightness 0..255 [0]
              Controls  the brightness of the acquired image.  Ignored for ACE
              capable scanners.

       --threshold 0..255 [0]
              Select minimum-brightness to get a white point.  Ignored for ACE
              capable scanners.

       --contrast 0..255 [inactive]
              Controls the contrast of the acquired image.  This option is not
              currently used by the scanner (and perhaps never will be).

       --negative[=(yes|no)] [no]
              Swap black and white, yielding a reverse-video image.

       Icon:

       --icon-width 0..3600pel (in steps of 8) [0]
              Width of icon (thumbnail) image in pixels.

       --icon-length 0..3600pel (in steps of 8) [0]
              Length of icon (thumbnail) image in pixels.

       Barcode Options:

       --barcode-search-bar <see list> [none]
              Specifies the barcode type to search for.  If this option is not
              specified,  or  specified with a value of none, then the barcode
              decoding feature is completely disabled.  The valid barcode type
              are:

              none
              ean-8
              ean-13
              reserved-ean-add
              code39
              code2-5-interleaved
              code2-5-3lines-matrix
              code2-5-3lines-datalogic
              code2-5-5lines-industrial
              patchcode
              codabar
              codabar-with-start-stop
              code39ascii
              code128
              code2-5-5lines-iata

       --barcode-search-count 1..7 [3]
              Number  of  times  that the RSC performs the decoding algorithm.
              Specify the smallest number possible  to  increase  performance.
              If  you are having trouble recognizing barcodes, it is suggested
              that you increase this option to its maximum value (7).

       --barcode-search-mode <see list> [horiz-vert]
              Chooses the orientation of barcodes to be searched.   The  valid
              orientations are:

              horiz-vert
              horizontal
              vertical
              vert-horiz

       --barcode-hmin 0..1660mm [5]
              Sets  the  barcode  minimum height in millimeters (larger values
              increase recognition speed).  Of course the actual  barcodes  in
              the document must be of sufficient size.

       --barcode-search-timeout 20..65535us [10000]
              Sets  the  timeout  for barcode searching in milliseconds.  When
              the timeout expires, the decoder will stop trying to decode bar-
              codes.

       --section <string> []
              Specifies  a series of image sections.  A section can be used to
              gather a subset image or to provide a small area for barcode de-
              coding.   Each  section  is  specified  in  the following format
              (units are in millimeters):

       <width>x<height>+<top-left-x>+<top-left-y>[:functioncode...]

       Multiple sections can be specified by separating them with commas.

       For example 76.2x25.4+50.8+0:frontbar identifies an area 3 inches  wide
       and  1  inch  high  with  a  top left corner at the top of the page two
       inches from the left hand edge of the page.  This section will be  used
       for barcode decoding on the front page only.

       For  example  50.8x25.4+25.4+0:frontbar:front:g42d identifies an area 2
       inches wide and 1 inch high with a top left corner at the  top  of  the
       page  one  inch from the left hand edge of the page.  This section will
       be used for barcode decoding on the front page as well as generating an
       image compressed in g42d format.

       Ordinarily  barcodes  are  searched in the entire image.  However, when
       you specify sections all barcode searching is done within the  specific
       sections  identified.   This  can  significantly  speed up the decoding
       process.

       The following function codes are available:

              front - generate an image for the front page section
              back - generate an image for the back page section
              frontbar - perform barcode search in front page section
              backbar - perform barcode search in back page section
              frontpatch - perform patchcode search in front page section
              backpatch - perform patchcode search in back page section
              none - use no image compression
              g31d - use Group 3 1 dimension image compression
              g32d - use Group 3 2 dimensions image compression
              g42d - use Group 4 2 dimensions image compression

       If you omit a compression functioncode, the full page compression  set-
       ting  is used.  If you specify multiple compression functioncodes, only
       the last one is used.

       --barcode-relmax 0..255 [0]
              Specifies the maximum relation from the widest to  the  smallest
              bar.

       --barcode-barmin 0..255 [0]
              Specifies the minimum number of bars in Bar/Patch code.

       --barcode-barmax 0..255 [0]
              Specifies the maximum number of bars in a Bar/Patch code.

       --barcode-contrast 0..6 [3]
              Specifies  the image contrast used in decoding.  Use higher val-
              ues when there are more white pixels in the code.

       --barcode-patchmode 0..1 [0]
              Controls Patch Code detection.


CONFIGURATION

       The contents of the bh.conf file is a list of device names that  corre-
       spond  to  Bell+Howell  scanners.   See sane-scsi(5) on details of what
       constitutes a valid device name.  Additionally, options can  be  speci-
       fied;  these  lines  begin  with the word "option".  Each option is de-
       scribed in detail below.  Empty lines and lines starting  with  a  hash
       mark (#) are ignored.


OPTIONS

       The following options can be specified in the bh.conf file.

       disable-optional-frames
              This  option  prevents  the  backend  from  sending any optional
              frames.  This option may be useful when dealing  with  frontends
              which do not support these optional frames.  When this option is
              in effect, the data is sent in a SANE_FRAME_GRAY frame.  The op-
              tional   frames  sent  by  this  backend  are:  SANE_FRAME_G31D,
              SANE_FRAME_G32D,  SANE_FRAME_G42D  and  SANE_FRAME_TEXT.   These
              frames  are  generated  based on the compression and barcode op-
              tions.  These frames are never sent in preview mode.

       fake-inquiry
              This option is used for debugging purposes and its  use  is  not
              encouraged.  Essentially, it allows the backend to initialize in
              the absence of a scanner.  This is useful  for  development  and
              not  much  else.   This  option must be specified earlier in the
              configuration file than the devices which are to be "faked".


FILES

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

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

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


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 config-
              uration file is searched in two default directories: first,  the
              current   working   directory   (".")   and   then  in  /usr/lo-
              cal/etc/sane.d.  If the value of the environment  variable  ends
              with  the directory separator character, then the default direc-
              tories are searched after the explicitly specified  directories.
              For example, setting SANE_CONFIG_DIR to "/tmp/config:" would re-
              sult in directories tmp/config, ., and /usr/local/etc/sane.d be-
              ing searched (in this order).

       SANE_DEBUG_BH
              If the library was compiled with debug support enabled, this en-
              vironment variable controls the debug level  for  this  backend.
              E.g.,  a  value  of 255 requests all debug output to be printed.
              Smaller levels reduce verbosity.


SUPPORTED FEATURES

       ADF support
              With document scanners, automatic document feeder (ADF)  support
              is  a  key feature.  The backend supports the ADF by default and
              returns SANE_STATUS_NO_DOCS when the out-of-paper  condition  is
              detected.  The SANE frontend scanadf(1) is a command line front-
              end that supports multi-page scans.  It has been  used  success-
              fully  with  this backend.  The SANE frontend xsane(1) is an im-
              proved GUI frontend by Oliver  Rauch.   Support  for  multi-page
              scans is included in xsane version 0.35 and above.

       Duplex scanning
              Some  models, such as the COPISCAN II 6338, support duplex scan-
              ning.  That is, they scan both sides of the  document  during  a
              single  pass  through the scanner (the scanner has two cameras).
              This backend supports duplex scanning  (with  the  --duplex  op-
              tion).   The  front  and back page images are delivered consecu-
              tively as if they were separately scanned pages.

       Hardware compression
              The scanner is capable of compressing the data into several  in-
              dustry standard formats (CCITT G3, CCITT G3-2D, CCITT G4).  This
              results in increased performance as less data is passed from the
              scanner  to  the  host  over the SCSI bus.  The backend supports
              these compression formats via the  --g31d,  --g32d,  --g42d  op-
              tions,  respectively.   Many  SANE frontends are not equipped to
              deal with these formats, however.  The SANE frontend  scanadf(1)
              supports  these  optional  frame  formats.  The compressed image
              data is written directly to a file and can then be processed  by
              a  scan-script using the --scan-script option.  Examples of this
              are given on the scanadf(1) homepage.

       Automatic Border Detection
              The scanner can automatically detect the paper size  and  adjust
              the  scanning  window  geometry appropriately.  The backend sup-
              ports this useful feature with the --autoborder option.   It  is
              enabled by default.

       Batch Mode Scanning
              The batch scan mode allows for maximum throughput.  The Set Win-
              dow parameters must remain constant during the entire batch.

       Icon Generation
              The Icon function generates a thumbnail of the full page  image,
              that can be transferred as if it were a separate page.  This al-
              lows the host to quickly display a thumbnail representation dur-
              ing  the  scanning operation.  Perhaps this would be a great way
              of implementing a preview scan, but since a normal  scan  is  so
              quick, it might not be worth the trouble.

       Multiple Sections
              Multiple  sections (scanning sub-windows) can be defined for the
              front and back pages.  Each section can have  different  charac-
              teristics  (e.g.  geometry,  compression).  The sections are re-
              turned as if they were separately scanned images.   Additionally
              sections  can  be used to greatly enhance the accuracy and effi-
              ciency of the barcode/patchcode decoding process by limiting the
              search area to a small subset of the page.  Most Copiscan II se-
              ries scanners support up to 8 user-defined sections.

       Support Barcode/Patchcode Decoding
              The RSC unit can recognize Bar and Patch Codes of various  types
              embedded  in  the  scanned image.  The codes are decoded and the
              data is returned to the frontend as a text frame.  The  text  is
              encoded  in  xml  and contains a great deal of information about
              the decoded data such as the location where it  was  found,  its
              orientation,  and the time it took to find.  Further information
              on the content of this text frame as well as some barcode decod-
              ing examples can be found on the backend homepage.


LIMITATIONS

       Decoding a single barcode type per scan
              The RSC unit can search for up to six different barcode types at
              a time.  While the code generally supports  this  as  well,  the
              --barcode-search-bar  option  only  allows the user to specify a
              single barcode type.  Perhaps  another  option  which  allows  a
              comma separated list of barcode type codes could be added to ad-
              dress this.

       Scanning a fixed number of pages in batch mode
              The separation of front  and  back  end  functionality  in  SANE
              presents  a problem in supporting the 'cancel batch' functional-
              ity in the scanner.  In batch mode, the scanner is always a page
              ahead  of  the host.  The host, knowing ahead of time which page
              will be the last, can cancel batch mode prior to initiating  the
              last  scan  command.  Currently, there is no mechanism available
              for the frontend to pass this  knowledge  to  the  backend.   If
              batch  mode  is enabled and the --end-count terminates a scanadf
              session, an extra page will be pulled through the  scanner,  but
              is neither read nor delivered to the frontend.  The issue can be
              avoided by specifying --batch=no when scanning a fixed number of
              pages.

       Revision 1.2 Patch detector
              There  is an enhanced patchcode detection algorithm available in
              the RSC with revision 1.2 or higher that is faster and more  re-
              liable  than  the  standard Bar/Patch code decoder.  This is not
              currently supported.


BUGS

       This is a new backend; detailed bug reports are welcome -- and expected
       ;)

       If  you have found something that you think is a bug, please attempt to
       recreate it with the SANE_DEBUG_BH environment variable set to 255, and
       send  a report detailing the conditions surrounding the bug to sane-de-
       vel@alioth-lists.debian.net.


SEE ALSO

       sane(7), sane-scsi(5), scanimage(1), scanadf(1), xsane(1)


AUTHOR

       The sane-bh backend was written by Tom Martone, based on  the  sane-ri-
       coh(5)  backend  by  Feico  W.  Dillema and the bnhscan program by Sean
       Reifschneider of tummy.com ltd.  Some 8000 enhancements added  by  Mark
       Temple.

                                  10 Jul 2008                       sane-bh(5)

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