ras_formats man page

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

Info

February 1993 NCAR VIEW