Small python script that adds some noise to all images in a dataset.

dataset_noiser.py

import os
import argparse
import numpy as np
from PIL import Image
from tqdm import tqdm


def add_gaussian_noise(image: Image, factor: float):
    """
    Add a given amount of white guassian noise to an image.
    
    Args:
        image (Image): original image.
        factor (float): amount of noise to mix, between 0 and 1.
    
    Returns:
        PIL.Image: The noisy image.
    """
    image_array = np.array(image)
    mean = 0
    sigma = factor * 255
    noise = np.random.normal(mean, sigma, image_array.shape)
    noisy_image = image_array + noise
    noisy_image = np.clip(noisy_image, 0, 255).astype(np.uint8)
    return Image.fromarray(noisy_image)

def main():
    parser = argparse.ArgumentParser(description='Adds Gaussian noise to images in a dataset.')
    parser.add_argument('--dataset', type=str, required=True, help='Path to the dataset directory.')
    parser.add_argument('--factor', type=float, required=True, help='Amount of noise to mix, between 0 and 1.')
    
    args = parser.parse_args()
    
    if not (0 <= args.factor <= 1):
        raise ValueError(f"The noise factor should be between 0 and 1 (got {args.factor}).")
    
    for filename in tqdm(os.listdir(args.dataset), "Adding noise", unit="img(s)"):
        if filename.lower().endswith(('.png', '.jpg', '.jpeg')):
            img_path = os.path.join(args.dataset, filename)
            image = Image.open(img_path).convert('RGB')
            noisy_image = add_gaussian_noise(image, args.factor)
            noisy_image.save(img_path)

if __name__ == '__main__':
    main()