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/arch_triplet/sane/libsane-dmc.a
              The static library implementing this backend.

       /usr/lib/arch_triplet/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)