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# sane-dmc.5

    sane-dmc(5)              SANE Scanner Access Now Easy              sane-dmc(5)

## NAME

           sane-dmc - SANE backend for the Polaroid Digital Microscope Camera

## DESCRIPTION

           The  sane-dmc library implements a SANE (Scanner Access Now Easy) back-
           end 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  corre-
           sponds  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 sup-
           ports 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  "Fluores-
                  cent"  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 corre-
           spond 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/local/etc/sane.d/dmc.conf
                  The   backend   configuration  file  (see  also  description  of
                  SANE_CONFIG_DIR below).

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

           /usr/local/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 config-
                  uration  file is searched in two default directories: first, the
                  current    working    directory    (".")     and     then     in
                  /usr/local/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 directo-
                  ries.  For example, setting  SANE_CONFIG_DIR  to  "/tmp/config:"
                  would    result    in   directories   "tmp/config",   ".",   and
                  "/usr/local/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

    sane-backends 1.0.12-cvs          13 May 1998                      sane-dmc(5)