Section: SANE Scanner Access Now Easy (5)
Updated: 10 Jul 2008
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 [email protected] 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:
This backend expects device names of the form:
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.
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.
The following options can be specified in the bh.conf file.
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.:
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.
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 [email protected].
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.
Tutoriais de Tecnologia Web