Perform operations on pixels in an image

pixels.py

import cv2
import numpy as np
from PIL import Image

def process_pixels(img):    
    pixel_data = list(img.getdata())
    pixels = np.array(pixel_data).flatten()
    width = img.size[0]
    height = img.size[1]

    # Perform operations on pixels
    print(pixels)

    pixel_data = []           
    for index in range(0, len(pixels), 3):
        pixel = []
        for offset in range(3):
            pixel.append(pixels[index + offset])
        pixel_data.append(tuple(pixel))

    img.putdata(pixel_data)
    return img

img = Image.open('image.png')
img = process_pixels(img)
img.show()