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@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 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.
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(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 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 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 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.
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
/opt/local/etc/sane.d/bh.conf
The backend configuration file (see also description of
SANE_CONFIG_DIR below).
/opt/local/lib/sane/libsane-bh.a
The static library implementing this backend.
/opt/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. On *NIX systems, 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
/opt/local/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
/opt/local/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(1) is a command line frontend
that supports multi-page scans. It has been used successfully
with this backend. The SANE frontend xsane(1) 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(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 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.
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@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-ricoh(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)
sane-backends 1.2.1 - Generated Sat Feb 25 11:23:37 CST 2023