I have the following image I and I want to add additive noise using the array N below. Can you please give me a calculation example of how to achieve this?

Do I have to move from image space to frequency space?

You don't have to go to the frequency domain to add noise. I'm not completely sure what you mean by adding it, because those number in N are quite big. Are those variances or actually sample values?

Adding them together can simply be done by well... adding them together (value by value). Since they both have the same size, this is possible.

Normally one would give a noise distribution with its paramters. Those random numbers can then be generated and added to each element of the matrix.

• Actually the don't have the same size. I = 4x4 and N = 4x3. The value are sample values. Do I have to calculate the variance? Nov 9, 2018 at 11:39
• Ou sorry just realized that. No you don't. Do you might have more details or maybe more information what I and N are? It's not clear what you actually try to do. If one would like to make an image noisy he could just add randn(1,1) e.g. to every single pixel. Your N is somehow weird. Nov 9, 2018 at 11:45