sane-dmc(5) SANE Scanner Access Now Easy sane-dmc(5)NAMEsane-dmc - SANE backend for the Polaroid Digital Micro-
scope 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 xscan-
image 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 mil-
liseconds. 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" set-
tings 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
/usr/freeware/etc/sane.d/dmc.conf
The backend configuration file (see also descrip-
tion of SANE_CONFIG_DIR below).
/usr/freeware/lib32/sane/libsane-dmc.a
The static library implementing this backend.
/usr/freeware/lib32/sane/libsane-dmc.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_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 buffer-
ing 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_STA-
TUS_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 ALSOsane(7), sane-scsi(5)AUTHOR
David F. Skoll
The backend is derived from sane-hp by David Mosberger
sane-backends 1.0.12 13 May 1998 sane-dmc(5)
