Image Thumbnail

You can use Matplotlib to generate thumbnails from existing images. Matplotlib relies on Pillow for reading images, and thus supports all formats supported by Pillow.

from argparse import ArgumentParser
from pathlib import Path
import sys

import matplotlib.image as image

parser = ArgumentParser(
    description="Build thumbnails of all images in a directory.")
parser.add_argument("imagedir", type=Path)
args = parser.parse_args()
if not args.imagedir.is_dir():
    sys.exit(f"Could not find input directory {args.imagedir}")

outdir = Path("thumbs")
outdir.mkdir(parents=True, exist_ok=True)

for path in args.imagedir.glob("*.png"):
    outpath = outdir / path.name
    fig = image.thumbnail(path, outpath, scale=0.15)
    print(f"saved thumbnail of {path} to {outpath}")