# Which type of noise can we see from the given image signal and its abs of 2D FFT?

1. Background:

I get an 128*128 2D one-channel noisy image as follows:

I get the shifted absolute values of 2D FFT result by the following Python code:

import numpy as np
import cv2

...

x = x.reshape(128, 128)
x_fft_abs = np.fft.fftshift(np.log(1 + np.abs(np.fft.fft2(x))))

...



2. My Question:

It seems that the latent clean image mainly consists of mid-/high-frequency components, since the lowest (central) and highest (marginal) values are significantly smaller.

However, since I know little about FFT and its properties, I do not know which type of noise affects the image, with regular (uniformly distributed) cross patterns (i.e., something like "+++++" in the 2D FFT abs result).

Could you please figure it out and tell me how to prevent it (or remove it) in my device?