vdcomp(1)                   General Commands Manual                  vdcomp(1)



[1mName[0m
       [4mvdcomp[24m - decompress a compressed PDS image

[1mSynopsis[0m
       [4mvdcomp[24m [ infile ] [ outfile ] [ format-code ]

[1mDescription[0m
       The  [4mvdcomp[24m  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.

[1mOptions[0m
       [4mVdcomp[24m  will  prompt  for any options that are not supplied on the com-
       mand-line.

       [4minfile[0m
              The name of compressed image file.

       [4moutfile[0m
              The name of uncompressed image file.

       [4mformat-code[0m
              Select from the following list:
                     [4m1[24m - SFDU/PDS format [default]
                     [4m2[24m - FITS format
                     [4m3[24m - VICAR format
                     [4m4[24m - unlabelled binary array

[1mLimitations[0m
       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 Macin-
       tosh IIx using Lightspeed C version 3.0.  When converting to other sys-
       tems, check for portability conflicts.

[1mCredits[0m
       This  program uses Kris Becker's subroutine DECOMP.C (which is included
       in this program in a shortened version).

[1mHistory[0m
       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  com-
       pressed  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.



                                                                     vdcomp(1)
