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<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 3.2//EN">
<HTML><HEAD><TITLE>Pbmclean User Manual</TITLE></HEAD>
<BODY>
<H1>pbmclean</H1>
Updated: 27 Feb 2005
<BR>
<A HREF="#index">Table Of Contents</A>

<A NAME="lbAB">&nbsp;</A>
<H2>NAME</H2>

pbmclean - flip isolated pixels in portable bitmap

<A NAME="lbAC">&nbsp;</A>
<H2>SYNOPSIS</H2>

<B>pbmclean</B>
[<B>-minneighbors=</B><I>N</I>]
[<B>-black</B>|<B>-white</B>]
[<I>pbmfile</I>]

<?makeman .SH OPTION USAGE ?>
<P>You can use the minimum unique abbreviation of the options.  You
can use two hyphens instead of one.  You can separate an option name
from its value with white space instead of an equals sign.

<A NAME="description">&nbsp;</A>
<H2>DESCRIPTION</H2>

<p>This program is part of <a href="index.html">Netpbm</a>.

<p><B>pbmclean</B> cleans up a PBM image of random specks.  It reads a
PBM image as input and outputs a PBM that is the same as the input
except with isolated pixels inverted.  An isolated pixel is one that
has very few neighboring pixels of the same color.  The
<b>-minneighbors</b> option gives the number of same-color neighbors
are required.

<P>The default is 1 pixel -- only completely isolated pixels are
flipped.

<P>(A <b>-minneighbors</b> value greater than 8 generates a completely
inverted image (but use <B>pnminvert</B> to do that) -- or a
completely white or completely black image with the <B>-black</B> or
<B>-white</B> option).

<P><B>pbmclean</B> considers the area beyond the edges of the image to
be white.  (This matters when you consider pixels right on the edge of
the image).

<P>You can use <B>pbmclean </B> to clean up &quot;snow&quot; on bitmap
images.

<A NAME="lbAE">&nbsp;</A>
<H2>OPTIONS</H2>

<DL COMPACT>
<DT><B>-black</B>

<DT><B>-white</B>

<DD>Flip pixels of the specified color.  By default, if you specify
neither <B>-black</B> nor <B>-white</B>, <B>pbmclean</B> flips both
black and white pixels which do not have sufficient identical
neighbors.  If you specify <B>-black</B>, <B>pbmclean</B> leaves the
white pixels alone and just erases isolated black pixels.  Vice versa
for <B>-white</B>.  You may specify both <B>-black</B> and
<B>-white</B> to get the same as the default behavior.

<dt><b>-minneighbors=</b><i>N</i>

<dd>This determines how many pixels must be in a cluster in order
for <b>pbmclean</b> to consider them legitimate and not clean them
out of the image.  See <a href="#description">Description</a>.

<P>Before December 2001, <B>pbmclean</B> accepted <B>-</B><I>N</I>
instead of <B>-minneighbors</B>.  Before Netpbm 10.27 (March 2005),
<b>-minneighbors</b> was <b>-minneighbor</b>.


</DL>

<A NAME="lbAF">&nbsp;</A>
<H2>SEE ALSO</H2>

<B><A HREF="pbm.html">pbm</A></B>

<A NAME="lbAG">&nbsp;</A>
<H2>AUTHOR</H2>

Copyright (C) 1990 by Angus Duggan
Copyright (C) 1989 by Jef Poskanzer.
Copyright (C) 2001 by Michael Sternberg.
<P>
Permission to use, copy, modify, and distribute this software and its
documentation for any purpose and without fee is hereby granted, provided
that the above copyright notice appear in all copies and that both that
copyright notice and this permission notice appear in supporting
documentation.  This software is provided &quot;as is&quot; without express or
implied warranty.

<HR>
<A NAME="index">&nbsp;</A>
<H2>Table Of Contents</H2>
<UL>
<LI><A HREF="#lbAB">NAME</A>
<LI><A HREF="#lbAC">SYNOPSIS</A>
<LI><A HREF="#description">DESCRIPTION</A>
<LI><A HREF="#lbAE">OPTIONS</A>
<LI><A HREF="#lbAF">SEE ALSO</A>
<LI><A HREF="#lbAG">AUTHOR</A>
</UL>
</BODY>
</HTML>