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


       The  sane-dmc  library  implements  a  SANE  (Scanner  Access Now Easy)
       backend that provides access to the Polaroid Digital Microscope Camera.


       This backend expects device names of the form:


       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.


       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.

              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.

              This mode corresponds to the 80-by-60 pixel full-color thumbnail

       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.)


       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.


       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:

              # this is a comment


              The  backend  configuration  file  (see  also   description   of
              SANE_CONFIG_DIR below).

              The static library implementing this backend.

              The shared library implementing this backend (present on systems
              that support dynamic loading).


              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).

              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.


       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

       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.


       sane(7), sane-scsi(5)


       David F. Skoll

       The backend is derived from sane-hp by David Mosberger

                                  13 Jul 2008                      sane-dmc(5)