\
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.TH "Pnmalias User Manual" 0 "15 March 2004" "netpbm documentation"

.SH NAME

pnmalias - antialias a PNM image

.UN synopsis
.SH SYNOPSIS

\fBpnmalias\fP

[\fB-bgcolor\fP \fIcolor\fP]

[\fB-fgcolor\fP \fIcolor\fP]

[\fB-bonly\fP]

[\fB-fonly\fP]

[\fB-balias\fP]

[\fB-falias\fP]

[\fB-weight\fP \fIw\fP]

[\fIpnmfile\fP]

.UN description
.SH DESCRIPTION
.PP
This program is part of
.BR "Netpbm" (1)\c
\&.
.PP
\fBpnmalias\fP reads a PNM image as input, and applies
anti-aliasing to background and foreground pixels.  If the input file
is a PBM, \fBpnmalias\fP promotes the output anti-aliased image to a
PGM, and prints a message informing the user of the change in format.

.UN options
.SH OPTIONS
.PP
In addition to the options common to all programs based on libnetpbm
(most notably \fB-quiet\fP, see 
.UR index.html#commonoptions
 Common Options
.UE
\&), \fBpnmalias\fP recognizes the following
command line options:
.PP
\fB-bgcolor\fP \fIcolorb\fP sets the background color the
\fIcolorb\fP.
.PP
\fB-fgcolor\fP \fIcolorf\fP sets the foreground color to
\fIcolorf\fP.
.PP
Pixels with these values will be anti-aliased.  By default,
\fBpnmalias\fP takes the background color to be black, and foreground
color to be white.
.PP
Specify the color (\fIcolor\fP) as described for the 
.UR libnetpbm_image.html#colorname
argument of the \fBpnm_parsecolor()\fP library routine
.UE
\&.
.PP
Note that even when dealing with PGMs, background and foreground
colors need to be specified in the fashion described above.  In this
case, \fBpnmalias\fP takes the background and foreground pixel values
to be the value of the red component for the specified color.
.PP
\fB-bonly\fP says to apply anti-aliasing only to the background pixels.
.PP
\fB-fonly\fP says to apply anti-aliasing only to the foreground pixels.
.PP
\fB-balias\fP says to apply anti-aliasing to all pixels surrounding
background pixels.
.PP
\fB-falias\fP says to apply anti-aliasing to all pixels surrounding
foreground pixels.
.PP
If you specify neither \fB-balias\fP nor \fB-falias\fP,
\fBpnmalias\fP applies anti-aliasing only among neighboring
background and foreground pixels.
.PP
\fB-weight\fP \fIw\fP says to use \fIw\fP as the central weight
for the aliasing filter.  \fIw\fP must be a real number in the range
0 < \fIw\fP < 1.  The lower the value of \fIw\fP is, the
"blurrier" the output image is.  The default is w = 1/3.

.UN seealso
.SH SEE ALSO
.BR "pbmtext" (1)\c
\&,
.BR "pnmsmooth" (1)\c
\&,
.BR "pnm" (5)\c
\&

.UN author
.SH AUTHOR

Copyright (C) 1992 by Alberto Accomazzi, Smithsonian Astrophysical Observatory.
.SH DOCUMENT SOURCE
This manual page was generated by the Netpbm tool 'makeman' from HTML
source.  The master documentation is at
.IP
.B http://netpbm.sourceforge.net/doc/pnmalias.html
.PP