Help for VGRCDCOPY

PURPOSE
    vgrcdcopy decompresses a Huffman First-Difference compressed
    VGR image, translating it from labeled image to a Voyager
    formatted VICAR image.

EXECUTION
    vgrcdcopy INP  OUT

NOTE:  VGRCDCOPY is not a VICAR program, but has a .pdf that is hard-coded
to run the application in $R2LIB.  To run the program from your directory,
simply run it from the command line:

   % ./vgrcdcopy INP OUT

EXAMPLE
    vgrcdcpy vg_0020:[000000.jupiter.c1940XXX]c1940944.imq   XXX.out
OUTPUT FILES
    a decompressed Voyager formatted Vicar Image.

OPERATION

  vgrcdcopy decompresses a Huffman First-Difference compressed
  VGR image, translating it from a PDS labeled image to a
  Voyager formatted VICAR image.  The binary headers and line
  prefixes are KEPT IN VAX-VMS FORMAT.  This should cause
  no problems since the next program run on this image is
  VGRFILLIN, which is advertised as being ported.

  The program verifies that the right number of parameters have	
  been entered.  Open file pointers to the files, exiting if problems.	

  The PDS label is parsed for information.  The Image histogram is read
  in from the file.  The 'missing lines' pixels in the 0 DN histogram 
  count are not included.  This can lead to histograms that don't sum to 
  640000 (800 x 800).	
									
  The histogram is written out as VAX formatted long ints.  
					
  Each variable length line is read in, decompressed , and written 
  to the output file.  Remember:  each line decompresses to a buffer 
  of 836 bytes.  The extra 36 bytes are the 'line suffix'.  This info 
  is described on the CD-ROM in the file /CDROM/label/linesufx.lbl			 Remember that the binary prefix for each line is 224 bytes long.	
  This will give a total line length of 1024 bytes.			
									
  The binary headers and prefixes are written in	
	VAX VAX VAX VAX VAX VAX VAX VAX VAX VAX VAX VAX VAX		
  format.  This should allow VGRFILLIN to run succesfully on any	
  platform, since it is advertised as being ported.			
  This is accomplished by simply moving the bytes to the correct	
  location in the prefix.  
		
PROGRAM HISTORY

    Original Programmer :  Myche McAuley  June 1995
    Cognizant Programmer:  Myche McAuley

REVISION HISTORY

    26 Mar 96  OAM  ...Revised to run on VMS. First Release. 
    
    

PARAMETERS: