sane-bh(5) SANE Scanner Access Now Easy sane-bh(5)
NAME
sane-bh - SANE backend for Bell+Howell Copiscan II series document scan-
ners
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 dur-
ing 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 documenta-
tion, 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); 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 op-
tion 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 unde-
sirable 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+Howell
scanner users' guide for complete information on ACE functional-
ity.
--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 in-
crease 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 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 bar-
code 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 im-
age 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 sec-
tions 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 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 corre-
spond to Bell+Howell scanners. See sane-scsi(5) on details of what con-
stitutes 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 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 en-
couraged. 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 configu-
ration file than the devices which are to be "faked".
FILES
/etc/sane.d/bh.conf
The backend configuration file (see also description of SANE_CON-
FIG_DIR below).
/usr/lib/x86_64-linux-gnu/sane/libsane-bh.a
The static library implementing this backend.
/usr/lib/x86_64-linux-gnu/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 directo-
ries are separated by a colon (`:'), under OS/2, they are sepa-
rated 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 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 fron-
tend 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 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 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 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 writ-
ten 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 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 character-
istics (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 orien-
tation, and the time it took to find. Further information on the
content of this text frame as well as some barcode decoding exam-
ples 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(1) ses-
sion, 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 reli-
able than the standard Bar/Patch code decoder. This is not cur-
rently supported.
BUGS
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 Reif-
schneider of tummy.com ltd. Some 8000 enhancements added by Mark Tem-
ple.
10 Jul 2008 sane-bh(5)
Generated by dwww version 1.16 on Sat Oct 3 07:13:21 CEST 2026.