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imnoise

Add noise to image

Description

This function adds noise to an input image.

Usage

imnoise(img, type = "gaussian", mean = 0, sd = 0.01, epsilon = 0.05, var = 0.04,
       looks = 1)

Arguments

img

input grayscale image matrix.
type

character string, specifying the type of contamination: "gaussian" (Gaussian white/additive noise), "saltnpepper" (salt and pepper noise or on-off noise), "speckle" (uniform multiplicative noise) and "gamma" (gamma multiplicative noise).
mean

mean for the Gaussian noise, default value is mean = 0.
sd

standard deviation for the Gaussian noise, default value is sd = 0.01.
epsilon

contamination percentage for the salt and pepper noise with default noise density 0.05. This affects approximately epsilon% of pixels.
var

variance of uniform multiplicative noise using the equation noise = img + unif * img, with unif is uniformly distributed with mean 0 and variance var. Default value is var = 0.04.
looks

parameter of gamma multiplicative noise. The default value is looks = 1.

Value

Noisy image, returned as a numeric matrix. The imnoise function clips output pixel values to the range [0,1] after adding noise.

Examples

data(texmos2)
  x <- imnoise(texmos2, type = "saltnpepper", epsilon = 0.10)
  plot(as.raster(x))

  y <- imnoise(texmos2, type = "speckle")
  plot(as.raster(y))

  z <- imnoise(texmos2, type = "gamma", looks = 4)
  plot(as.raster(z))
SpatialPack

Tools for Assessment the Association Between Two Spatial Processes

v0.3-8196
GPL-3
Authors
Felipe Osorio [aut, cre] (<https://orcid.org/0000-0002-4675-5201>), Ronny Vallejos [aut] (<https://orcid.org/0000-0001-5519-0946>), Francisco Cuevas [ctb], Diego Mancilla [ctb]
Initial release
2020-09-21

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