Add Gaussian noise to an image of type np.uint8.

add_gaussian_noise.py

import numpy as np
def add_gaussian_noise(image, mean=0, sigma=20):
    """Add Gaussian noise to an image of type np.uint8."""
    gaussian_noise = np.random.normal(mean, sigma, image.shape)
    gaussian_noise = gaussian_noise.reshape(image.shape)
    noisy_image = image + gaussian_noise
    noisy_image = np.clip(noisy_image, 0, 255)
    noisy_image = noisy_image.astype(np.uint8)
    return noisy_image