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UNEXP(1)		    General Commands Manual		      UNEXP(1)

       unexp - Convert "exponential" files into	normal files.

       unexp [ -m maxval ] [ -o	outfile	] [ -p ] [ -s ]	[ -v ] infile

       Unexp  Converts	a  file	of "exponential" floating point	values into an
       RLE(5) file containing integer valued bytes.   Exponential  files  have
       N-1  channels of	eight bit data,	with the Nth channel containing	a com-
       mon exponent for	the other channels.  This  allows  the	values	repre-
       sented by the pixels to have a wider dynamic range.

       If  no  maximum	value  is specified, unexp first reads the RLE file to
       find the	dynamic	range of the whole file.  It then rewinds the file and
       scales the output to fit	within that dynamic range.  If a maximum value
       is specified, unexp runs	in one pass, and clamps	any  values  exceeding
       the maximum.

       Files  containing  exponential  data  are  expected to have a "exponen-
       tial_data" comment; unexp prints	a warning if such  a  comment  doesn't
       exist.  An exponential file should be unexp'ed before attempting	to use
       any tools that perform arithmetic on pixels (e.g., rlecomp(1), avg4(1),
       fant(1),	or applymap(1))	or displaying the image.

       Unexp  does not allow piped input.  The infile must be a	real file; the
       special filenames described in urt(1) are not allowed.  ("-" does work,
       as  long	 as  the  input	is coming from a real file; this is of minimal
       utility,	therefore, as typing unexp - _foo.rle is  harder  than	typing
       unexp foo.rle.)

       -m maxval
	      Specify the maximum value	(i.e., the data	in the file is assumed
	      to be in the range 0..maxval).  Only the conversion pass is exe-
	      cuted, and values	found exceeding	the maximum are	clamped.

       -o outfile
	      If  specified, the output	will be	written	to this	file.  If out-
	      file is "-", or if it is not specified, the output will be writ-
	      ten to the standard output stream.

       -p     Print the	maximum	value found during the scanning	phase

       -s     Just  scan the file to find the maximum, don't generate any out-

       -v     Verbose mode, print a message to stderr after scanning  or  con-
	      verting every hundred scanlines.

       float_to_exp(3),	urt(1),	RLE(5).

       John W. Peterson

       Unexp  is  provided  because  of	the lack of floating point or extended
       precision RLE files.

       The -v flag is a	historical relict from the slow	CPU days.

4th Berkeley Distribution      November	8, 1987			      UNEXP(1)


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