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
       scanners.  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
       following 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@lists.alioth.debian.org 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
       Manual Version 1.5.  The Linux SCSI programming HOWTO, the SANE API
       documentation, 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.

CONFIGURATION
       The contents of the bh.conf file is a list of device names that
       correspond to Bell+Howell scanners.  See sane-scsi(5) on details of
       what constitutes a valid device name.  Additionally, options can be
       specified; these lines begin with the word "option".  Each option is
       described 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
              optional 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
              options.  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
       /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
              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_BH
              If the library was compiled with debug support enabled, this
              environment 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 is a command line frontend
              that supports multi-page scans.  It has been used successfully
              with this backend.  The SANE frontend xsane is an improved 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
              scanning.  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
              option).  The front and back page images are delivered
              consecutively as if they were separately scanned pages.


       Hardware compression
              The scanner is capable of compressing the data into several
              industry 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 options, respectively.  Many SANE frontends are not
              equipped to deal with these formats, however.  The SANE frontend
              scanadf 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 homepage.


       Automatic Border Detection
              The scanner can automatically detect the paper size and adjust
              the scanning window geometry appropriately.  The backend
              supports 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
              Window 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
              allows the host to quickly display a thumbnail representation
              during 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
              characteristics (e.g. geometry, compression).  The sections are
              returned as if they were separately scanned images.
              Additionally sections can be used to greatly enhance the
              accuracy and efficiency of the barcode/patchcode decoding
              process by limiting the search area to a small subset of the
              page.  Most Copiscan II series 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
              decoding 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
              address 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'
              functionality 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
              reliable than the standard Bar/Patch code decoder.  This is not
              currently supported.


OPTIONS
       Scan Mode Options:

       --preview[=(yes|no)] [no]
              Request a preview-quality scan.  When preview is set to yes
              image 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
              option is provided to allow multiple image scans with xsane; it
              has no other purpose.

       --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
              POSITION 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
              produce undesirable results.

       Enhancement:

       --control-panel[=(yes|no)] [yes]
              Enables the scanner's control panel for selecting image
              enhancement parameters.  When the option is set to no the
              following options are used to control image enhancement.  See
              the Bell+Howell scanner users' guide for complete information on
              ACE functionality.

       --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
              barcodes.

       --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
              decoding.  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 functioncodes 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
       setting 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
              values when there are more white pixels in the code.

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


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-devel@lists.alioth.debian.org.


SEE ALSO
       sane(7), sane-scsi(5), scanimage(1), scanadf(1)


AUTHOR
       The sane-bh backend was written by Tom Martone, based on the sane-ricoh
       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)
