vdcomp(1)vdcomp(1)Namevdcomp - decompress a compressed PDS image
Synopsisvdcomp [ infile ] [ outfile ] [ format-code ]
Description
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 porta-
bility 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 std-
out for output filename; disabled various messages;
directed messages to stderr; added exit status
DEC89 Modified program to handle both Voyager and Viking
images.
1
vdcomp(1)vdcomp(1)
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 file-
names 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.
2