NAME

       ras_formats - Information on raster formats supported by NCAR Graphics and NCAR View.

SYNOPSIS

       Abekas A60, AVS, Generic Binary, HDF, HPPCL, NRIF, Sun, SGI, and XWD.

DESCRIPTION

       NCAR  Graphics  and  NCAR  View applications are built upon a common library that provides
       read and write access to raster imagery. The table below summarizes the  support  that  is
       provided  for  all  the  different  formats.   Note that a format may be writeable but not
       readable, and that a compressed image may be readable but not  writeable.  By  default,  a
       raster  image  is  written as compressed if possible. For those applications that key upon
       the filename to determine the raster format, or allow a -ifmt or -ofmt, the extension,  as
       listed below, should be used without the "."  in front (e.g. use "hdf", not ".hdf").

       Format(extensions)   Encoding    Input   Output   Compression
       ──────────────────────────────────────────────────────────────

       Abekas A60(.a60)     RGB24        Yes     Yes        None
       AVS(.avs)            RGB24        Yes     Yes        None
       HDF(.hdf)            Indexed-8    Yes     Yes       In/Out
       HDF(.hdf)            Direct-24    Yes     Yes       In/Out
       HPPCL(.hppcl)        Indexed-8    No      Yes         Out
       NRIF(.nrif)          Bilevel      No       No        None
       NRIF(.nrif)          Indexed-8    Yes     Yes       In/Out
       NRIF(.nrif)          Direct-24    Yes     Yes       In/Out
       Sun(.sun)            Indexed-8    Yes     Yes         In
       Sun(.sun)            Direct-24    Yes      No         In
       SGI(.sgi,.rgb)       Direct-24    Yes     Yes         In
       XWD(.xwd)            Indexed-8    Yes     Yes        None

       ──────────────────────────────────────────────────────────────

CAVEATS

       Not  all  formats and encodings that are supported for output are supported for input; the
       software has separate input and output drivers for format/encoding pair.

       For all the  formats  listed  below,  only  8-bit  pixels  and  8-bit  run-lengths  (where
       applicable) are supported.

       Experience  with HDF's "advanced" compression option indicates that you should use it only
       if you consider random pixels an advanced-appearing image.

SEE ALSO

       rasview(1NCARG), rasls(1NCARG), rascat(1NCARG), rasgetpal(1NCARG), rassplit(1NCARG)

       Hardcopy: NCAR Graphics Fundamentals, UNIX Version

COPYRIGHT

       Copyright (C) 1987-2009
       University Corporation for Atmospheric Research

       The use of this Software is governed by a License Agreement.