Why is the use of randn in matlab?

sig = 0.05;
randn('seed', 0);            % generate seed
x = im + sig*randn(size(im)); % noisy observation

What is the need of seed generation in this code? Here im represents an image.

Answer 1

[Walter Roberson]

Gaussian noise is random by definition. If there were a pattern to it then it would be some other kind of noise.

In particular it is Normal Distribution noise as opposed to uniform random

[D Joseph]

Thanks @Roberson

Answer 2

[Steven Lord]

You shouldn't be using that syntax to change generators, for reasons described in the documentation. Use RNG instead.

D Joseph, I've noticed you've been asking a lot of very basic questions. This leads me to think that you're new to MATLAB, am I right? If so, I highly recommend reading through the Getting Started section of the MATLAB documentation (open the documentation by typing "doc matlab" without the quotes in the Command Window then look for the Getting Started link.) That documentation is not too long, and it includes a lot of examples, but it may help you become familiar with the syntax and the general usage of MATLAB.

[D Joseph]

Thanks@Steven