.TH IM_ADDGNOISE 3 "14 May 1991"
.SH NAME
im_addgnoise \- add gaussian noise to an image
.SH SYNOPSIS
#include <vips/vips.h>

int im_addgnoise(in, out, sigma)
.br
IMAGE *in, *out;
.br
double sigma;

.SH DESCRIPTION
im_addgnoise() adds gaussian noise with mean 0 and standard deviation sigma to
the image held by the image descriptor in and writes the result on the image
descriptor out.  The function works on any non-complex input image. 
Input can have any no of bands.  The noise is generated by adding
12 random numbers.

.SH RETURN VALUE
The function returns 0 on success and -1 on error.
.SH SEE ALSO
im_add(3), im_lintra(3), im_multiply(3).
.SH COPYRIGHT
N. Dessipris
.SH AUTHOR
N. Dessipris \- 25/04/1991