NAME
sane-canon_dr - SANE backend for Canon DR-series scanners
DESCRIPTION
The sane-canon_dr library implements a SANE (Scanner Access Now Easy)
backend which provides access to some Canon DR-series scanners.
This document describes backend version 35, which shipped with SANE
1.0.21.
SUPPORTED HARDWARE
This version has only been tested with a few scanner models. Please see
http://www.sane-project.org/sane-supported-devices.html for the most
recent list.
This backend may support other Canon scanners. The best way to
determine level of support is to test the scanner directly, or to
collect a trace of the windows driver in action. Please contact the
author for help or with test results.
In general, the larger machines (DR-4000 and up) which have been tested
use a fairly complete protocol, with hardware support for many modes,
resolutions and features. The smaller machines have many limitations,
like missing horizontal resolutions, missing binary mode, always
scanning full-width, etc. There is code in the backend to address
these problems, but there seems to be no way to detect if they are
required, so they must be hard-coded.
OPTIONS
Effort has been made to expose most hardware options, including:
source s
Selects the source for the scan. Options may include "Flatbed",
"ADF Front", "ADF Back", "ADF Duplex".
mode m
Selects the mode for the scan. Options may include "Lineart",
"Halftone", "Gray", and "Color".
resolution
Controls scan resolution.
tl-x, tl-y, br-x, br-y
Sets scan area upper left and lower right coordinates. These are
renamed t, l, x, y by some frontends.
page-width, page-height
Sets paper size. Used by scanner to determine centering of scan
coordinates when using ADF and to detect double feed errors.
Other options will be available based on the capabilities of the
scanner: enhancement, compression, buttons and sensors, etc.
Additionally, several ’software’ options are exposed by the backend.
These are reimplementations of features provided natively by larger
scanners, but running on the host computer. This enables smaller
machines to have similar capabilites. Please note that these features
are somewhat simplistic, and may not perform as well as the native
implementations. Note also that these features all require that the
driver cache the entire image in memory. This will almost certainly
result in a reduction of scanning speed.
swcrop
Requests the driver to detect the extremities of the paper
within the larger image, and crop the empty edges.
swdeskew
Requests the driver to detect the rotation of the paper within
the larger image, and counter the rotation.
swdespeck X
Requests the driver to find and remove dots of X diameter or
smaller from the image, and fill the space with the average
surrounding color.
Use ’scanimage --help’ to get a list, but be aware that some options
may be settable only when another option has been set, and that
advanced options may be hidden by some frontend programs.
CONFIGURATION FILE
The configuration file "canon_dr.conf" is used to tell the backend how
to look for scanners, and provide options controlling the operation of
the backend. This file is read each time the frontend asks the backend
for a list of scanners, generally only when the frontend starts. If the
configuration file is missing, the backend will fail to run.
Scanners can be specified in the configuration file in 4 ways:
"scsi CANON DR"
Requests backend to search all scsi busses in the system for a
device which reports itself to be a scanner made by ’CANON’,
with a model name starting with ’DR’.
"scsi /dev/sg0" (or other scsi device file)
Requests backend to open the named scsi device. Only useful if
you have multiple compatible scanners connected to your system,
and need to specify one. Probably should not be used with the
other "scsi" line above.
"usb 0x04a9 0x1603" (or other vendor/product ids)
Requests backend to search all usb busses in the system for a
device which uses that vendor and product id. The device will
then be queried to determine if it is a Canon scanner.
"usb /dev/usb/scanner0" (or other device file)
Some systems use a kernel driver to access usb scanners. This
method is untested.
Besides the ’scsi’ and ’usb’ lines, the configuration file supports the
following ’option’ lines:
"option buffer-size [number of bytes]"
Set the number of bytes in the data buffer to something other
than the compiled-in default of 4MB. Large values may cause
timeouts or hangs, small values may cause slow scans.
Note: The backend does not place an upper bound on this value,
as some users required it to be quite large. Values above the
default are not recommended, and may crash your OS or lockup
your scsi card driver. You have been warned.
"option vendor-name [string of text]"
"option model-name [string of text]"
"option version-name [string of text]"
These options can be used collectively to override the values
provided by the scanner, or to provide the values when the
scanner cannot.
"option padded-read [0|1]"
Some scanners prepend all data transmitted to host with 12
bytes. Enable this option if the scanner fails to respond to
commands.
Note: ’option’ lines may appear multiple times in the configuration
file. They only apply to scanners discovered by the next ’scsi/usb’
line.
ENVIRONMENT
The backend uses a single environment variable, SANE_DEBUG_CANON_DR,
which enables debugging output to stderr. Valid values are:
5 Errors
10 Function trace
15 Function detail
20 Option commands
25 SCSI/USB trace
30 SCSI/USB detail
35 Useless noise
KNOWN ISSUES
This backend was entirely reverse engineered from usb traces of the
proprietary driver. Various advanced features of the machines may not
be enabled. Many machines have not been tested. Their protocol is
unknown.
CREDITS
The various authors of the sane-fujitsu backend provided useful code
Corcaribe Tecnología C.A. www.cc.com.ve provided significant funding
EvriChart, Inc. www.evrichart.com provided funding and loaned equipment
Canon, USA. www.usa.canon.com loaned equipment
HPrint hprint.com.br provided funding and testing for DR-2510 support
Stone-IT www.stone-it.com provided funding for DR-2010 and DR-2050
support
Special thanks to: Alejandro Imass, Andre Shimakawa, Martijn van
Brummelen, Thanos Diacakis and Junren Shi for testing and feedback.
SEE ALSO
sane(7), sane-scsi(5), sane-usb(5)
AUTHOR
m. allan noah: <kitno455 a t gmail d o t com>
10 Feb 2010 sane-canon_dr(5)