ras_formats
Information on raster formats supported by NCAR Graphics and its
translators.
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, rasls, rascat, rasgetpal,
rassplit
Copyright
Copyright © 1987-1999
University Corporation for Atmospheric Research
The use of this
software and documentation is governed by a License Agreement.