The vdcomp program reads a variable length compressed PDS image
and outputs a fixed length uncompressed image file in PDS format with
labels, image histogram, engineering table, line header table and an
image with PDS, FITS, VICAR or no labels.
If used on a non-byte-swapped machine the image histogram is
un-swapped.
Options
Vdcomp will prompt for any options that are not supplied on the
command-line.
infile
The name of compressed image file.
outfile
The name of uncompressed image file.
format-code
Select from the following list:
1 - SFDU/PDS format [default]
2 - FITS format
3 - VICAR format
4 - unlabelled binary array
Limitations
This program has been tested on a VAX 780 (VMS 4.6), SUN Workstation
(UNIX 4.2, release 3.4), an IBM PC (MICROSOFT 5.1 compiler) and
Macintosh IIx using Lightspeed C version 3.0. When converting to
other systems, check for portability conflicts.
Credits
This program uses Kris Becker's subroutine DECOMP.C (which is included
in this program in a shortened version).
History
bradley@cis.upenn.edu 06-23-94 ansi-fied program
datri@convex.com, 11-15-91 added recognition of - as stdout for output
filename; disabled various messages; directed messages to stderr;
added exit status
DEC89 Modified program to handle both Voyager and Viking images.
OCT89 Converted Voyager decompression program to handle Viking
compressed images. Changed obuf to 'unsigned' to simplify computation
of checksum.
AUG89 Added code to get command line arguments for filenames and
output format; routines to free memory used by the Huffman tree);
fixed the SFDU label output length; and modified the I/O routines so
that the open for Host type 2 uses binary I/O.
JUN89 Fixed READVAR, to get length on 16-bit unswapped hosts.
JUL88 C driver to decompress standard Voyager Compressed images by
Mike Martin 1989/12/02.