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
       /etc/sane.d/dmc.conf
	      The   backend   configuration  file  (see	 also  description  of
	      SANE_CONFIG_DIR below).

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

       /usr/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 /etc/sane.d.	If the
	      value  of the environment variable ends with the directory sepa-
	      rator 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



sane-backends 1.0.18		  13 May 1998			   sane-dmc(5)