sane-canon - SANE backend for Canon flatbed scanners
The sane-canon library implements a SANE (Scanner Access Now Easy)
backend that provides access to the following Canon flatbed scanners:
CanoScan 300
CanoScan 600
CanoScan 2700F
No parallel port and USB scanners are supported and there are no plans
to support them in the future.
IMPORTANT: this is alpha code. Don't expect this to work correctly.
Many functions are missing, others contain errors. In some cases, your
computer might even hang. It cannot be excluded (although I consider it
extremely unprobable) that your scanner will be damaged.
That said, TESTERS ARE WELCOME. Send your bug reports and comments to
Manuel Panea <[email protected]>.
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. The special device name must be a generic SCSI
device or a symlink to such a device. The program sane-find-scanner
helps to find out the correct device. Under Linux, such a device name
could be /dev/sga or /dev/sge, for example. See sane-scsi(5) for
details.
The contents of the canon.conf file is a list of device names that correspond
to Canon scanners. Empty lines and lines starting with a hash
mark (#) are ignored. Only one device name can be listed in
canon.conf.
When scanning either slides or negatives, I found that I must set the
gamma value to something about 2.2 to 2.4 (I set the same value for all
three red, green, blue). Also, for slides, using "Auto Exposure" helps
a lot.
The "Auto Exposure" function for slides makes the scanner do a first
pass on the film to determine the Highlight and Shadow point values.
The "Auto Focus" function triggers yet another pass to determine the
focus value. After that, the real scanning pass takes place. The "Auto
Exposure" function is not available for negatives yet.
Even after "Auto Focus", the image I get is often a bit too blurred. I
found that using the GIMP to do a "Filter->Enhance->Sharpen" at about
40 to 60 improves the image quite a bit. In fact, I find it so good
that I might implement a sharpen filter into the backend in the future.
The "native" scanner resolutions of the 2700F are the integer sub-multiples
of 2720 dpi, i.e. 1360, 680, 340 and 170. You can scan at any
other resolution, but you will notice that the image has noticeably
more jaggies that when using one of the "native" resolutions.
/etc/sane.d/canon.conf
The backend configuration file (see also description of
SANE_CONFIG_DIR below).
/usr/lib/sane/libsane-canon.a
The static library implementing this backend.
/usr/lib/sane/libsane-canon.so
The shared library implementing this backend (present on systems
that support dynamic loading).
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_CANON [Toc] [Back]
If the library was compiled with debug support enabled, this
environment variable controls the debug level for this backend.
Higher debug levels increase the verbosity of the output.
Example: export SANE_DEBUG_CANON=4
sane(7), sane-scsi(5), sane-find-scanner(1)
http://www.rzg.mpg.de/~mpd/sane/
/usr/doc/sane-1.0.7/canon/canon.install2700F.txt (installation of a
CanoScan 2700F)
Helmut Koeberle, Manuel Panea, and Markus Mertinat
Man page by Henning Meier-Geinitz (mostly based on canon.README)
29 May 2001 sane-canon(5)
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