#!/usr/bin/env python

import h5py
import numpy as np


#image = np.zeros((512, 1024), dtype=int)
image = np.zeros((10, 10), dtype=int)

values = [3, 11, 128]
#N = 10000 # per value
N = 10 # per value

width = max(values).bit_length()

for val in values:
    print(f"{val:0{width}b}")
    idx = np.random.choice(image.size, size=N, replace=False)
    image.flat[idx] = val

with h5py.File("example.h5", "x") as f:
    f["pixel_mask"] = image