.\" Copyright (c) 1990, University of Michigan
.TH RLESPIFF 1 "June 12, 1990" 1
.UC 4 
.SH NAME
rlespiff \- Use simple contrast enhancement to "spiff up" an image.
.SH SYNOPSIS
.B rlespiff
[
.B \-b
.I blacklevel
] [
.B \-s
] [
.B \-t
.I threshold
] [
.B \-w 
.I whitelevel
] [
.B \-o 
.I outfile 
] [
.I infile
]
.SH DESCRIPTION
.I Rlespiff
"spiffs up" an
image by stretching the contrast range so that the darkest pixel maps
to black and the lightest to white.  If the
.B \-s
flag is given, the color channels will be treated separately.  This
will likely cause some drastic color shifts.
.SH OPTIONS
.TP
.BI \-b \ blacklevel
The darkest input pixel will map to this pixel value in the
output image.  The default is 0.
.TP
.B \-s
If specified, each color channel will be mapped separately.
.TP
.BI \-t \ threshold
This argument controls the number of samples of a pixel value that
should be considered insignificant (and will therefore be ignored).
It is specified in pixels/million.  A threshold of 4 applied to a
512x512 image would mean that any value that existed at only one pixel
would be ignored.  The default value is 10.
.TP
.BI \-w \ whitelevel
The lightest input pixel will map to this pixel value in the output
image.  The default is 255.
.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
.I infile
The input will be read from this file.  If
.I infile
is "\-" or is not specified, the input will be read from the standard
input stream.
.SH SEE ALSO
.IR urt (1),
.IR RLE (5).
.SH AUTHOR
Spencer W. Thomas