On 3 Dec 2012, at 00:05, Terry Duell wrote:
You could also try something like this...
bb = aa + 3/256*randn(h,w);
where h,w are the height, width of aa.
The first approach takes 13.74 sec here, for my little test image. The
second takes about 0.01 sec.
The results appear quite similar, but I guess it depends on your
particular need.
that is equivalent to
bb = imnoise (aa, 'gaussian', 0, sqrt(3/256))
which works the same in Matlab and Octave, the version I proposed
is equivalent to
bb = imnoise (aa, 'poisson')
which is not yet implemented in Octave: