Example of a shared buffer between file (mmap), numpy array and Pillow image

example.py

import mmap

from PIL import Image
import numpy as np


size = 32 * 32 * 4
f = open('f.bin', 'w+b')
f.truncate(size)
mm = mmap.mmap(f.fileno(), size)
mm[:] = (np.arange(size) % 199).astype(np.uint8)
data = np.frombuffer(mm, dtype=np.uint8).reshape(32, 32, 4)
img = Image.fromarray(data, 'RGBX')
img.show()