NAME

     ifwc2snr - Fast Wavelet Packet  Decompression  2D  Keywords:
     wavelet compression signal noise ratio

SYNOPSIS

     ifwc2snr [ -Nntap ] [ -Ootap ] [ -rsirs ] [ -reire ] [ -buf-
     fersize ] [ -nolh ] [ -verify ] [ -VT ] [ -V ] [ -help -h -?
     ]

DESCRIPTION

     ifwc2snr performs very fast wavelet packet based  decompres-
     sion  in  2D. The the header elements are decompressed using
     gzip.  The user may specify the record range  to  decompress
     from  within  the compressed volume.  A verify flag has been
     added to allow the user to  verify  upon  compression  [with
     fwc2snr]   that   all   data   expected  has  actually  been
     compressed.
     ifwc2snr gets both its data and its parameters from  command
     line  arguments.  These arguments specify the input, output,
     the buffer size, the line header status, the record  limits,
     the  verify  flag,  the completion estimate flag and verbose
     printout, if desired.

  Command line arguments
     -N ntap  [stdin]
          Enter the input data set name or file immediately after
          typing -N unless the input is from a pipe in which case
          the -N entry must be omitted.  This input  file  should
          include the complete path name if the file resides in a
          different directory.  Example -N/b/vsp/dummy tells  the
          program to look for file 'dummy' in directory '/b/vsp'.

     -O otap  [stdout]
          Enter the output data  set  name  or  file  immediately
          after typing -O.  This output file is not required when
          piping the output to another process.  The output  data
          set also requires the full path name (see above).

     -verify
          enter the command line argument '-verify' to verify the
          record  count  of a compressed dataset.  This is useful
          immediately after a compression using fwc2 to make sure
          the whole dataset is there.  If something nasty occured
          during compression [like a network failure] it is often
          not  immediately obvious that the compressed dataset is
          incomplete.  Finding this out after the initial dataset
          has been erased is bad.  Running -verify is recommended
          as a QC step.  It runs very quickly as all it has to do
          is count records.

     -buffer rate  [system buffer size]
          enter the desired I/O buffer size.

     -rs irs  [start record]
          enter the sequential start record to decompress

     -re ire  [last record]
          enter the sequential end record to decompress

     -VT  Enter the command line argument '-VT' to get  run  time
          estimates during execution.

     -V   Enter the command line argument '-V' to get  additional
          printout.

     -? or -h or -help
          Enter the command line argument '-?' or  -h  or   -help
          to  get  online help.  The program terminates after the
          help screen is printed.

DISCUSSION

     This product is licensed from Fast  Mathematical  Algorithms
     and Hardware Inc.  It is proprietary to BP Amoco and may not
     be ported to applications or locations outside  the  company
     without the expressed written permission of GeoEnergy Corp.

     There are a few  advanced  options built into  this  release
     to  help  with  corrupt compressed data volumes.  This some-
     times occurs when disk errors or tape parity error have been
     encountered.   If  you  are  playing  with  these option you
     really need to be talking with Joe Wade in  Tulsa.   We  are
     putting them here to remind us that they exist and what they
     are used for.


     -salvage
          Enter the command line argument '-salvage'  to  attempt
          to decompress a corrupt compressed volume.  The routine
          will attempt to skip past a corrupt entry and  continue
          on the next recognizable compressed block.

     -nolh
          Enter the command line argument '-nolh'  if  the  input
          dataset does not have a line header.  This option comes
          in handy when dealing with corrupt data.

     -offset
          Enter the byte offset to the start of data to  be  sal-
          vaged.

DISCUSSION

     This  product  is  licensed  from  GeoEnergy  Inc.   It   is
     proprietary  to  BP  Amoco and may not be ported to applica-
     tions or locations outside the company without the expressed
     written permission

BUGS

     none known at present

AUTHOR

     Anthony Vassiliou (GeoEnergy Inc.  918-494-4641),  Joe  Wade
     (socon 421-3324)

COPYRIGHT

     copyright 2001, Amoco Production Company
               All Rights Reserved
          an affiliate of BP America Inc.