sane-canon_pp(5) SANE Scanner Access Now Easy sane-canon_pp(5)NAMEsane-canon_pp - SANE backend for Canon CanoScan Parallel
Port flatbed scanners
DESCRIPTION
The sane-canon_pp library implements a SANE (Scanner
Access Now Easy) backend that provides access to the fol-
lowing Canon flatbed scanners:
CanoScan FB320P
CanoScan FB620P
CanoScan FB330P
CanoScan FB630P
CanoScan N340P
CanoScan N640P
CanoScan N640P ex
No USB scanners are supported and there are no plans to
support them in the future. Other projects are working on
support for USB scanners. See the PROJECTS file for more
detail. The FB310P and FB610P are re-badged Avision scan-
ners which use a different command set, so are unlikely to
be supported by this backend in the future.
IMPORTANT: this is alpha code. While we have made every
effort to make it as reliable as possible, it will not
always work as expected. Feedback is still appreciated.
Please send any bug reports to the maintainers as listed
on the web page (listed in SEE ALSO below).
DEVICE NAMES
This backend expects device names of the form presented by
libieee1284. These names are highly dependent on operat-
ing system and version.
On Linux 2.4 kernels this will be of the form parport0 or
older (2.2 and before) kernels may produce names like
0x378 (the base address of your port) or simply 0 depend-
ing on your module configuration. Check the contents of
/proc/parport if it exists. If you don't want to specify
a default port (or don't know its name), the backend
should be able to detect which port your scanner is on.
CONFIGURATION
The contents of the canon_pp.conf file is a list of
options for the driver to use. Empty lines and lines
starting with a hash mark (#) are ignored.
The supported options are currently ieee1284, calibrate,
init_mode, and force_nibble
Option ieee1284 port-name defines which port to use. The
format of port-name is OS dependent, based on the names
presented by libieee1284. Please only have one of these
lines, or all but one will be ignored.
Option calibrate cal-file [port-name] defines which cali-
bration file to use on a per-port basis. If you only have
one parport, the port-name argument may be omitted - but
be careful as this will cause problems on multi-scanner
systems. You may have as many of these lines as you like,
as long as each has a unique port name. The tilde (`~')
character is acceptable and will be expanded to the value
of the HOME environment.
Option init_mode <AUTO|FB620P|FB630P> [portname] defines
which initialisation (wake-up) mode to use on a per-port
basis. If you only have one parport, the portname argu-
ment may be omitted - but be careful as this may cause
problems on multi-scanner systems. You may have as many
of these lines as you like, as long as each has a unique
port name. The valid initialisation modes are FB620P
(which strobes 10101010 and 01010101 on the data pins),
FB630P (which strobes 11001100 and 00110011 on the data
pins) and AUTO, which will try FB630P mode first then
FB620P mode second. The FB620P mode is also used by the
FB320P. The FB630P mode is used by the FB330P, N340P, and
N640P.
Option force_nibble forces the driver to use nibble mode
even if ECP mode is reported to work by libieee1284. This
works-around the rare issue of ECP mode being reported to
work by the library, then not working.
TIPS
Hit the "Calibrate" button before scanning. It vastly
improves the quality of scans.
To enable automatic detection of your scanner, uncomment
the "canon_pp" line from /usr/freeware/etc/sane.d/dll.conf
FILES
/usr/freeware/etc/sane.d/canon_pp.conf
The backend configuration file (see also descrip-
tion of SANE_CONFIG_DIR below).
/usr/freeware/lib32/sane/libsane-canon_pp.a
The static library implementing this backend.
/usr/freeware/lib32/sane/libsane-canon_pp.so
The shared library implementing this backend (pre-
sent on systems that support dynamic loading).
ENVIRONMENT
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 /usr/freeware/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 spec-
ified directories. For example, setting SANE_CON-
FIG_DIR to "/tmp/config:" would result in directo-
ries "tmp/config", ".", and "/usr/free-
ware/etc/sane.d" being searched (in this order).
SANE_DEBUG_CANON_PP
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_PP=4
NOTES
Features available in the Windows interface
Brightness and Contrast
These are not implemented, and probably never will
be. These appear to be implemented entirely in
software. Use GIMP or a similar program if you
need these features.
Descreen Mode
This appears on our first analysis to be just over-
sampling with an anti-aliasing filter. Again, it
seems to be implemented entirely in software, so
GIMP is your best bet for now.
Gamma Tables
This is under investigation, but for now only a
simple gamma profile (ie: the one returned during
calibration) will be loaded.
Communication Problems
ECP mode in libieee1284 doesn't always work properly, even
with new hardware. We believe that this is a ppdev prob-
lem. If you change the configuration file to include
force_nibble , the problem will go away, but you will only
be able to scan in nibble mode.
Sometimes the scanner can be left in a state where our
code cannot revive it. If the backend reports no scanner
present, try unplugging the power and plugging it back in.
Also try unplugging printers from the pass-through port.
The scanner will not respond correctly to our commands
when you first plug in the power. You may find if you try
a scan very soon after plugging in the power that the
backend will incorrectly report that you have no scanner
present. To avoid this, give it about 10 seconds to reset
itself before attempting any scans.
Repeated Lines
Sometimes at high resolutions (ie. 600dpi) you will notice
lines which appear twice. These lines correspond to
points where the scanner head has stopped during the scan
(it stops every time the internal 64kb buffer is full).
Basically it's a mechanical problem inside the scanner,
that the tolerance of movement for a start/stop event is
greater than 1/600 inches. I've never tried the windows
driver so I'm not sure how (or if) it works around this
problem, but as we don't know how to rewind the scanner
head to do these bits again, there's currently no nice way
to deal with the problem.
Grey-scale Scans
Be aware that the scanner uses the green LEDs to read
grey-scale scans, meaning green coloured things will
appear lighter than normal, and red and blue coloured
items will appear darker than normal. For high-accuracy
grey-scale scans of colour items, it's best just to scan
in colour and convert to grey-scale in graphics software
such as the GIMP.
FB620P/FB320P Caveats
These models can not be reset in the same way as the oth-
ers. The windows driver doesn't know how to reset them
either - when left with an inconsistent scanner, it will
start scanning half way down the page!
Aborting is known to work correctly on the FB*30P models,
and is known to be broken on the FB*20P models. The
FB620P which I tested on simply returns garbage after a
scan has been aborted using the method we know. Aborting
is able to leave the scanner in a state where it can be
shut down, but not where another scan can be made.
SEE ALSOsane(7), sane-dll(5) http://canon-fb330p.sourceforge.net/
AUTHOR
This backend is primarily the work of Simon Krix (Reverse
Engineering), and Matthew Duggan (SANE interface).
Many thanks to Kevin Easton for his comments and help, and
Kent A. Signorini for his help with the N340P.
sane-backends 1.0.12 1 October 2002 sane-canon_pp(5)
