Pamaddnoise User Manual

# pamaddnoise

Updated: 12 December 2020
Table Of Contents

## NAME

pamaddnoise - add noise to a Netpbm image

## SYNOPSIS

pamaddnoise
{
[-type gaussian] [-sigma1 value] [-sigma2 value]
|
-type multiplicative_gaussian [-mgsigma value]
|
-type impulse [-tolerance ratio]
|
-type laplacian [-lsigma value]
|
-type poisson [-lambda value]
}
[-seed int] [netpbmfile]

## DESCRIPTION

This program is part of Netpbm.

pamaddnoise adds the specified noise type to a Netpbm image. pamaddnoise treats a PPM image as 3 independent planes, not as a plane of colors in a color space.

## OPTIONS

In addition to the options common to all programs based on libnetpbm (most notably -quiet, see Common Options), pamaddnoise recognizes the following command line options:

-lambda value
  This is the expected value of the Poisson distribution for a sample value of mximum intensity. The expected value for other intensities is proportional; e.g. for half intensity, it is half this value.

  This is meaningful only with -type=poisson.

  The default value is 12.

-lsigma value
  Used for laplacian noise only. The default value is 10.0.
-mgsigma value
  Used for multiplicative gaussian noise only. The default value is 0.5.
-seed int
  Used for all noise types. Set the initial random number generator seed value.
-sigma1 value
  Used for gaussian noise only. The default value is 4.0.
-sigma2 value
  Used for gaussian noise only. The default value is 20.0.
-tolerance ratio
  Used for impulse noise only. The default value is 0.10. This means that 5% of all pixel values will be set to 0 and 5% will be set to the maxval
-type noise_type
  Select type of noise by name. The following noise types are available: gaussian, multiplicative_gaussian, impulse, laplacian, poisson. Only enough letters to be unique are required for the noise type option. The default noise type is gaussian.
  - gaussian
  - multiplicative_gaussian
  - impulse
  - laplacian
  - poisson

## REFERENCES

- "Adaptive Image Restoration in Signal-Dependent Noise" by R. Kasturi Institute for Electronic Science, Texas Tech University, 1982
- "Digital Image Processing Algorithms" by Ioannis Pitas, Prentice Hall, 1993 ISBN 0-13-145814-0

## SEE ALSO

pgmnoise, pgmmedian, pnm, pam,

## HISTORY

pamaddnoise was added to Netpbm in Version 10.29 (August 2005). It had been distributed by Mike Burns via his own web site before that (and continued to be so).

Burns' version, and the one in Netpbm 10.29, was called pnmaddnoise and worked only on PNM images. In Netpbm 10.30, it was converted to handle PAM images and renamed to pamaddnoise.

## AUTHOR

Copyright (C) 1995 by Mike Burns <burns@cac.psu.edu>

## Table Of Contents

- SYNOPSIS
- DESCRIPTION
- OPTIONS
- REFERENCES
- SEE ALSO
- HISTORY
- AUTHOR