1#!/usr/bin/env python3
2"""
3Adds a white border of consistent width around an image.
4
5I use it when I've taken a screenshot of something on a white background,
6and I want to tidy up the crop quickly.
7"""
8
9import argparse
10import os
11
12from PIL import Image, ImageChops, ImageOps
13
14
15def parse_args():
16    parser = argparse.ArgumentParser()
17
18    parser.add_argument("PATH")
19    parser.add_argument("BORDER_WIDTH", type=int)
20    parser.add_argument("--in-place", action="store_true")
21
22    return parser.parse_args()
23
24
25if __name__ == "__main__":
26    args = parse_args()
27
28    im = Image.open(args.PATH)
29
30    bg = Image.new(im.mode, im.size, (255, 255, 255))
31
32    diff = ImageChops.difference(im, bg)
33    diff = ImageChops.add(diff, diff, 2.0, -100)
34    bbox = diff.getbbox()
35    if bbox:
36        im = im.crop(bbox)
37
38    im = ImageOps.expand(im, border=args.BORDER_WIDTH, fill="white")
39
40    name, ext = os.path.splitext(args.PATH)
41
42    if args.in_place:
43        out_path = args.PATH
44    else:
45        out_path = f"{name}.reborder_{args.BORDER_WIDTH}{ext}"
46
47    im.save(out_path)
48
49    print(out_path)