scanadf is a command-line interface to control image acquisition devices which
are capable of returning a series of images (e.g. a scanner with an
automatic document feeder (ADF)). The device is controlled via
command-line options. After command-line processing,
scanadf normally proceeds to acquire a series of images until the device returns
SANE_STATUS_NO_DOCS status code.
The images are written to output files, specified by the
--output-file option. These files are typically written in one of the PNM (portable aNyMaP)
formats (PBM for black-and-white images, PGM for grayscale images,
and PPM for color images). Several optional frame formats (SANE_FRAME_JPEG,
SANE_FRAME_G31D, SANE_FRAME_G32D, SANE_FRAME_G42D, and SANE_FRAME_TEXT)
are supported. In each case, the data is written out to the output file
as-is without a header. Unrecognized frame formats are handled in
the same way, although a warning message is printed in verbose mode.
Typically, the optional frame formats are used in conjunction with a scan
script (specified by the
--scanscript option) which is invoked for each acquired image. The script is provided
with a series of environment variables which describe the parameters
and format of the image file.
scanadf accesses image acquisition devices through the SANE (Scanner Access
Now Easy) interface and can thus support any device for which there
exists a SANE backend (try "apropos sane-" to get a list of available
--device-name options must be followed by a SANE device-name. A (partial) list of
available devices can be obtained with the
--list-devices option (see below). If no device-name is specified explicitly,
scanadf will attempt to open the first available device.
--help options request help information. The information is printed on
standard output and in this case, no attempt will be made to acquire
--list-devices option requests a (partial) list of devices that are available. The
list is not complete since some devices may be available, but are not
listed in any of the configuration files (which are typically stored
in directory /usr/local/etc/sane.d). This is particularly the case when
accessing scanners through the network. If a device is not listed in
a configuration file, the only way to access it is by its full device
name. You may need to consult your system administrator to find out
the names of such devices.
--verbose options increase the verbosity of the operation of
scanadf. The option may be specified repeatedly, each time increasing the verbosity
--version option requests that
scanadf print the program and package name, as well as the version number of
the SANE distribution that it came with.
--output-file option specifies a format string used to generate the name of file to
write the image data to. You can use %d replacement in the output file
name; this will be replaced with the current page number. The default
format string is image-%04d.
--no-overwrite option prevents
scanadf from overwriting existing image files.
--scan-script option specifies the name of script to run after each scanned image
is acquired. The script receives the name of the image output file
as its first and only command line argument. Additionally the scan
script can reference the following environment variables to get
information about the parameters of the image.
SCAN_RES - the image resolution (in DPI)
SCAN_WIDTH - the image width (in pixels)
SCAN_HEIGHT - the image height (in pixels)
SCAN_DEPTH - the image bit-depth (in bits)
SCAN_FORMAT - a string representing the image format (e.g. gray, g42d, text, etc)
SCAN_FORMAT_ID - the numeric image format identifier
--scipt-wait option is given, scanadf will wait until all scan-scripts have been finished before
exiting. That will be useful if scanadf is used in conjunction with tools to modify
the scanned images.
--start-count option specifies the page number of first scanned image.
--end-count option specifies the last page number to scan. Using this option,
you can request a specific number of pages to be scanned, rather than
scanning until there are no more images available.
--raw option specifies that the raw image data be written to the output file
as-is without interpretation. This disables the writing of the PNM
header for basic frame types. This feature is usually used in
conjunction with the
--scan-script option where the scan script uses the environment variables to
understand the format and parameters of the image and converts
the file to a more useful format. NOTE: With support for the
optional frame types and the default handling of unrecognized
frametypes, this option becomes less and less useful.
As you might imagine, much of the power of
scanadf comes from the fact that it can control any SANE backend. Thus, the
exact set of command-line options depends on the capabilities of the
selected device. To see the options for a device named
scanadf via a command-line of the form:
scanadf --help --device
The documentation for the device-specific options printed by
--help is explained in the manual page for