\
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.\" Do not hand-hack it!  If you have bug fixes or improvements, please find
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.TH "Ppmspread User Manual" 0 "06 March 2021" "netpbm documentation"

.SH NAME

ppmspread - displace a PPM image's pixels by a random amount

.UN synopsis
.SH SYNOPSIS

\fBppmspread\fP \fIamount\fP [\fIppmfile\fP]
[\fB-randomseed=\fP\fIinteger\fP]


.UN description
.SH DESCRIPTION
.PP
This program is part of
.BR "Netpbm" (1)\c
\&.
.PP
\fBppmspread\fP reads a PPM image as input and moves every pixel
around a random bit relative to its original position. \fIamount\fP
determines by how many pixels a pixel is to be moved around at most.
.PP
Pictures processed with this filter will seem to be somewhat
dissolved or unfocussed (although they appear more coarse than images
processed by something like \fIpnmconvol\fP).
.PP
The randomness in the image is limited before Netpbm 10.37 (December
2006) -- if you run the program twice in the same second, you may get
identical output.


.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
\&), \fBppmspread\fP recognizes the following
command line options:


  
.TP
\fB-randomseed=\fP\fIinteger\fP
This is the seed for the random number generator that generates the
pixels.
.sp
Use this to ensure you get the same image on separate invocations.
.sp
This option was new in Netpbm 10.94 (March 2021).



  
.UN seealso
.SH SEE ALSO
.BR "ppm" (1)\c
\&, 
.BR "pnmconvol" (1)\c
\&

.UN author
.SH AUTHOR

Copyright (C) 1993 by Frank Neumann
.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/ppmspread.html
.PP