NAME
sane-dmc - SANE backend for the Polaroid Digital Microscope Camera
DESCRIPTION
The sane-dmc library implements a SANE (Scanner Access Now Easy)
backend that provides access to the Polaroid Digital Microscope Camera.
DEVICE NAMES
This backend expects device names of the form:
special
Where special is the UNIX path-name for the special device that
corresponds to the scanner. The special device name must be a generic
SCSI device or a symlink to such a device. Under Linux, such a device
name could be /dev/sga or /dev/sge, for example.
IMAGING MODES
The Polaroid DMC supports a number of imaging modes. This driver
supports five of the imaging modes:
Full Frame
This mode corresponds to the 801-by-600 pixel full-color full-
frame image.
Viewfinder
This mode corresponds to the 270-by-201 pixel grey-scale
viewfinder image. This image is acquired very quickly.
Raw This mode corresponds to the 1599-by-600 pixel "raw" image from
the CCD. It is grey-scale, with pixels alternating horizontally
between red, green and blue stripes. The pixels are twice as
high as they are wide, so the image is distorted.
Thumbnail
This mode corresponds to the 80-by-60 pixel full-color thumbnail
image.
Super Resolution
This image is a 1599-by-1200 pixel full-color image constructed
by filtering and interpolating the "raw" image. The filtering
and interpolation is done in software, so this mode is very
slow. Also, this mode places restrictions on how the image is
read which means that the "preview" mode of xscanimage does not
work in Super Resolution mode. (xcam and the non-preview modes
of scanimage and xscanimage work fine, however.)
OTHER SETTINGS
ASA Setting
This setting adjusts the camera’s sensitivity. You can choose
one of 25, 50, or 100 "equivalent" ASA.
Shutter Speed
You can select a shutter speed from 8 to 1000 milliseconds. The
shutter speed is quantized in units of 32 microseconds.
White Balance
You can choose one of "Daylight", "Incandescent" or
"Fluorescent" white balances. This setting more-or-less
corresponds to the "Color Temperature" settings on Polaroid’s
Windows and Mac software.
CONFIGURATION
The contents of the dmc.conf file is a list of device names that
correspond to DMC scanners. Empty lines and lines starting with a hash
mark (#) are ignored. A sample configuration file is shown below:
/dev/scanner
# this is a comment
/dev/sge
FILES
/etc/sane.d/dmc.conf
The backend configuration file (see also description of
SANE_CONFIG_DIR below).
/usr/lib/sane/libsane-dmc.a
The static library implementing this backend.
/usr/lib/sane/libsane-dmc.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_DMC
If the library was compiled with debug support enabled, this
environment variable controls the debug level for this backend.
E.g., a value of 128 requests all debug output to be printed.
Smaller levels reduce verbosity.
BUGS
In the "Full Frame" and "Raw" modes, images must be read in units of
entire lines. The driver performs no buffering in these modes; if you
ask sane_read to read a non-integral number of lines, it may read less
than you ask for. If you ask sane_read to read less than a single
line, it returns SANE_STATUS_INVAL.
In the "Super Resolution" mode, images must be read in units of two
lines (3198 pixels or 9594 bytes.) If you try to read less than two
lines, you get SANE_STATUS_INVAL. The Super Resolution mode is very
slow.
In the "Viewfinder" and "Thumbnail" modes, the entire image must be
read in one SCSI transfer. In this case, the driver performs buffering
and you can read the image in as small an increment as you like.
SEE ALSO
sane(7), sane-scsi(5)
AUTHOR
David F. Skoll
The backend is derived from sane-hp by David Mosberger
13 Jul 2008 sane-dmc(5)