.\" Copyright (c) 1986, University of Utah
.\" Template man page.  Taken from wtm's page for getcx3d
.TH UNEXP 1 "November 8, 1987" 1
.UC 4 
.SH NAME
unexp \- Convert "exponential" files into normal files.
.SH SYNOPSIS
.B unexp
[
.B \-m
.I maxval
] [
.B \-o
.I outfile
] [
.B \-p
] [
.B \-s
] [
.B \-v
] 
.I infile
.SH DESCRIPTION
.IR Unexp
Converts a file of "exponential" floating point values into an 
.IR RLE (5)
file containing integer valued bytes.  Exponential files have N-1 channels of
eight bit data, with the Nth channel containing a common exponent for
the other channels.  This allows the values represented by the pixels to have 
a wider dynamic range.

If no maximum value is specified, 
.I 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,
.I unexp
runs in one pass, and clamps any values exceeding the maximum.  

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

.I Unexp
does not allow piped input.  The
.I infile
must be a real file; the special filenames described in 
.IR 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 
.I "unexp - <foo.rle"
is harder than typing
.IR "unexp foo.rle" .)
.SH OPTIONS
.TP
.BI \-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 executed, and values found 
exceeding the maximum are clamped.
.TP
.BI \-o \ outfile
If specified, the output will be written to this file.  If 
.I outfile
is "\-", or if it is not specified, the output will be written to the
standard output stream.
.TP
.B \-p
Print the maximum value found during the scanning phase
.TP
.B \-s
Just scan the file to find the maximum, don't generate any output.
.TP
.B \-v
Verbose mode, print a message to stderr after scanning or converting every 
hundred scanlines.
.SH SEE ALSO
.IR float_to_exp (3),
.IR urt (1),
.IR RLE (5).
.SH AUTHOR
John W. Peterson
.SH BUGS
.I Unexp
is provided because of the lack of floating point or extended
precision RLE files.

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