Is there a way to report Noise Variance?

[MrBled]

I am experimenting with generate_dataset.py and ISP_implement.py and I am trying to return sigma_s and sigma_c to find an approximation of the noise value. I have tried doing sigma*255 and also np.sqrt(sigma)*255 but the numbers returned do not make sense for sigma_c (they are very low).

Is there a way of finding the chosen variance for both sigma_c and sigma_s? in terms of [0-255]

Thanks