# How can i compute noise (1 sigma error) given a signal

I have a signal organized as an image, i.e. a matrix. Each "pixel" has an error $$\sigma_{i,j}$$. Simplifying, let's assume that the error is the same for all the involved "pixels". How can I compute the corresponding noise associated to each pixel at 1 sigma error? Clearly, I'm assuming a gaussian distribution for the noise for each pixel.

• Do you mean standard error or standard deviation. The two are not the same? – Dave Mar 21 at 14:38
• @Dave: sorry, i simply meant that the error on pixels is the same across the signal. It's only a simplification. – Giuseppe Angora Mar 21 at 17:33