from pathlib import Path
from PIL import Image, ImageChops
root = Path(__file__).parent
before = Image.open(root / "B1-stable-late.png").convert("RGB")
after = Image.open(root / "A1-after-grace.png").convert("RGB")
assert before.size == after.size
diff = ImageChops.difference(before, after)
diff.point(lambda x: min(255, x * 8)).save(root / "phone-diff-zero-amplified.png")
channels = diff.split()
maximum = ImageChops.lighter(ImageChops.lighter(channels[0], channels[1]), channels[2])
mask = maximum.point(lambda x: 255 if x > 16 else 0)
threshold = Image.new("RGB", before.size, "black")
threshold.paste((255, 0, 255), (0, 0), mask)
threshold.save(root / "phone-diff-threshold16.png")