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(1) does not work in Super Resolution mode.  (xcam(1) and the  non-preview  modes  of
              scanimage(1) and xscanimage(1) 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/x86_64-linux-gnu/sane/libsane-dmc.a
              The static library implementing this backend.

       /usr/lib/x86_64-linux-gnu/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.  On *NIX systems, 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

       Dianne Skoll <dianne@skoll.ca>

       The backend is derived from sane-hp(5) by David Mosberger.

                                                   13 Jul 2008                                       sane-dmc(5)