sane-canon_pp(5)

NAME
sane-canon_pp - SANE backend for Canon Parallel Port flatbed scanners

DESCRIPTION
The sane-canon_pp library implements a SANE (Scanner Access Now Easy) backend that provides access to the following Canon flatbed scanners:

    CanoScan FB330P
    CanoScan FB630P
    CanoScan N340P
    CanoScan N640P

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. We cannot add support for the FB310P or FB320P at the moment, but contact us if you have one of these scanners and would really like to help.

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 dependant on operating system and version. On Linux 2.4 kernels this will be of the form parport0 or older (2.2) kernels may produce names like 0x378 or simply 0 depending 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, and force_nibble Option ieee1284 portname defines which port to use. The format of portname is OS dependant, 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 [portname] defines which calibration file to use on a per-port basis. If you only have one scanner, the portname 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 expaned to the value of the HOME environment. 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 /etc/sane.d/dll.conf

FILES

/etc/sane.d/canon_pp.conf
    The backend configuration file (see also description of SANE_CONFIG_DIR below).

/usr/lib/sane/libsane-canon_pp.a
    The static library implementing this backend.

/usr/lib/sane/libsane-canon_pp.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. 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_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 implented 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 oversampling with an anti-aliasing filter. Again, it seems to be implemeneted 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 will be loaded.

Other Notes

ECP mode in libieee1284 doesn't always work properly, even with new hardware. We beleive that this is a ppdev problem. 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 passthrough 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.

SEE ALSO
sane(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.