BCI NET/BCI NET Dec 94.iso/archives/programming/source/thesource6.dms/thesource6.adf/Source/Compression/hcompress.lha/hcompress/vms/hcompress.com

Text File | 1992-04-24 | 3.7 KB | 133 lines

$! hcompress.com
$!
$! VMS command file to do H-transform image compression for a list of image
$! files in .hhh, .hhd format.  *.hhd files are replaced by *.hhd_H.
$!
$! Program will compress only I*2 images with no group parameters.
$! (A warning is issued for other images.)
$!
$! The default compression scale factor is 666, which is appropriate for
$! gasp images (gives about a factor of 10 compression, negligible loss in
$! information.)
$!
$! R. White, 20 April 1992
$!
$! determine where this procedure lives (assume that the executable files
$! are in this same directory)
$!
$ shellfile=f$parse(f$environment("procedure"),,,,"NO_CONCEAL")-"]["
$ cdir=f$extract(0,f$locate("]",shellfile),shellfile) + "]"
$ prgnam=f$parse(shellfile,,,"NAME")
$!
$ echo:=write sys$output
$ hc:=$'cdir'hcomp
$!
$ if p1.eqs.""
$ then
$    echo "Usage: ",prgnam," [options] files... [options] files..."
$    echo "  where options are:"
$    echo "     -s scale to specify the compression scale factor"
$    echo "     -k       to keep the uncompressed file (default)"
$    echo "     -r       to remove the uncompressed file"
$    echo ""
$    echo "Default compression scale factor is 666 (good for GASP images.)"
$    echo "Specify .hhd extension on files.  Compressed files are named *.*_H."
$    exit
$ endif
$!
$ scale=666
$ nextscale=0
$ remove=0
$ p=1
$ ploop:
$   parm = p'p
$   if parm.eqs."" then exit                ! all done
$   if nextscale.eq.1
$   then
$      scale=parm                    ! set scale
$      nextscale=0
$      echo "Using scale ", scale
$      goto endploop
$   endif
$   if parm.eqs."-S"
$   then
$      nextscale=1                    ! next parm is scale
$      goto endploop
$   endif
$   if parm.eqs."-R"
$   then
$      remove=1                        ! remove original files
$      goto endploop
$   endif
$   if parm.eqs."-K"
$   then
$      remove=0                        ! keep original files
$      goto endploop
$   endif
$!
$! compress the file(s) specified by this parameter
$! use f$search to allow the use of wildcards in file specifications
$!
$   datafile=f$search(parm,1)                ! get original file name
$   if datafile.eqs.""
$   then
$      echo prgnam,": ",datafile,": No such file"
$      goto endploop
$   endif
$!
$! save name of first file to correct the stupid behavior of f$search
$! when the file argument does not contain a wildcard character
$!
$   firstfile=datafile
$ floop:
$      dext=f$parse(datafile,,,"TYPE")
$      hext=f$extract(0,3,dext)+"H"
$      headfile=f$parse(hext+";",datafile,,,"SYNTAX_ONLY")    ! header name
$      cext=dext+"_H"
$      compfile=f$parse(cext+";",datafile,,,"SYNTAX_ONLY")    ! compress name
$!
$! check that header file exists
$! if compressed file already exists, we'll rely on VMS to create a new version
$!
$      if f$extract(3,1,dext).nes."D"
$      then
$         echo prgnam,": ",datafile," does not have .xxd extension"
$         goto endfloop
$      endif
$      if f$search(headfile,2).eqs.""
$      then
$         echo prgnam,": ",headfile,": No such file"
$         goto endfloop
$      endif
$!
$! perform compression
$!
$      echo datafile
$      define/user sys$output 'compfile'
$      hc -v -s 'scale' -i hhh 'datafile' 'headfile'
$      if $status.eq.1                ! check for success
$      then
$         if remove.eq.1 then delete 'datafile'    ! delete original file
$      else
$         echo prgnam,": ",datafile," not compressed: compression error"
$         delete 'compfile'                ! delete compressed file
$      endif
$ endfloop:
$!
$! get next file name
$!
$! be careful: f$search returns the same name every time if there are
$! no wildcard characters in the argument (dumb)
$!
$      datafile=f$search(parm,1)
$      if datafile.nes.firstfile
$      then
$         if datafile.nes."" then goto floop
$      endif
$!
$! go to next parameter
$!
$ endploop:
$   p = p+1
$   goto ploop