s202226701051/word-app/scripts/make_logo_transparent.py

"""
Make logo.png background transparent (vectorized, fast).
Writes to logo.png.tmp then replaces — avoids corrupting the file on failure.

Tune WHITE_* if edges of the logo are eaten or background remains.
"""
from __future__ import annotations

import os

import numpy as np
from PIL import Image

PATH = r"D:\worksspace\s202226701051\word-app\src\assets\icon\logo.png"
TMP = PATH + ".tmp.png"

# Pixels matching "light background" become transparent
WHITE_MIN = 236   # channel minimum for near-white
WHITE_AVG = 242   # average RGB
WHITE_SPREAD = 28 # max(r,g,b)-min(r,g,b); logo colors usually higher spread


def main() -> None:
    im = Image.open(PATH).convert("RGB")
    rgb = np.array(im)
    r = rgb[:, :, 0].astype(np.int16)
    g = rgb[:, :, 1].astype(np.int16)
    b = rgb[:, :, 2].astype(np.int16)
    avg = (r + g + b) / 3
    spread = np.maximum(np.maximum(r, g), b) - np.minimum(np.minimum(r, g), b)

    near_white = (
        (r >= WHITE_MIN) & (g >= WHITE_MIN) & (b >= WHITE_MIN)
    ) | ((avg >= WHITE_AVG) & (spread <= WHITE_SPREAD))

    rgba = np.zeros((rgb.shape[0], rgb.shape[1], 4), dtype=np.uint8)
    rgba[:, :, :3] = rgb
    rgba[:, :, 3] = np.where(near_white, 0, 255).astype(np.uint8)

    out = Image.fromarray(rgba, "RGBA")
    out.save(TMP, "PNG", optimize=True)
    Image.open(TMP).load()
    os.replace(TMP, PATH)
    print("OK:", PATH, "transparent count:", int(near_white.sum()))


if __name__ == "__main__":
    main()