<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 3.2//EN">
<HTML><HEAD><TITLE>Ppmdist User Manual</TITLE></HEAD>
<BODY>
<H1>ppmdist</H1>
Updated: 22 July 1992
<BR>
<A HREF="#index">Table Of Contents</A>
<A NAME="lbAB"> </A>
<H2>NAME</H2>
ppmdist - simplistic grayscale assignment for machine generated, color images
<A NAME="lbAC"> </A>
<H2>SYNOPSIS</H2>
<B>ppmdist</B>
[<B>-intensity</B>|<B>-frequency</B>]
[<I>ppmfile</I>]
<A NAME="lbAD"> </A>
<H2>DESCRIPTION</H2>
<p>This program is part of <a href="index.html">Netpbm</a>.
<p><b>ppmdist</b> reads a PPM image as input and performs a simplistic
grayscale assignment intended for use with grayscale or bitmap
printers.
<P>Often conversion from ppm to pgm will yield an image with contrast
too low for good printer output. The program maximizes contrast
between the gray levels output.
<P>A ppm input of n colors is read, and a pgm of n gray levels is
written. The gray levels take on the values 0..n-1, while maxval
takes on n-1.
<P>The mapping from color to stepped grayscale can be performed in
order of input pixel intensity, or input pixel frequency (number of
repetitions).
<p>This program is helpful only for images with a very small number of
colors.
<A NAME="lbAE"> </A>
<H2>OPTIONS</H2>
<DL COMPACT>
<DT><B>-frequency</B>
<DD>Sort input colors by the number of times a color appears in the
input, before mapping to evenly distributed graylevels of output.
<DT><B>-intensity</B>
<dd>Sort input colors by their grayscale intensity, before mapping to
evenly distributed graylevels of output. This is the default.
</DL>
<A NAME="lbAG"> </A>
<H2>SEE ALSO</H2>
<A HREF="ppmtopgm.html">ppmtopgm</A>,
<A HREF="ppmhist.html">ppmhist</A>,
<A HREF="ppm.html">ppm</A>
<A NAME="lbAH"> </A>
<H2>AUTHOR</H2>
Copyright (C) 1993 by Dan Stromberg.
<HR>
<A NAME="index"> </A>
<H2>Table Of Contents</H2>
<UL>
<LI><A HREF="#lbAB">NAME</A>
<LI><A HREF="#lbAC">SYNOPSIS</A>
<LI><A HREF="#lbAD">DESCRIPTION</A>
<LI><A HREF="#lbAE">OPTIONS</A>
<LI><A HREF="#lbAG">SEE ALSO</A>
<LI><A HREF="#lbAH">AUTHOR</A>
</UL>
</BODY>
</HTML>