gistfile1.txt

from PIL import Image, ImageEnhance
import os
from os.path import join


def start():
    batch("img_source_dir", "img_result_dir", "watermark.png")


def batch(infolder, outfolder, watermark):
    mark = Image.open(watermark)
    for root, dirs, files in os.walk(infolder):
        for name in files:
            im = Image.open(join(root, name))
            mark = mark.resize((im.size[0], im.size[1]), Image.ANTIALIAS)
            if im.mode != 'RGBA':
                im = im.convert('RGBA')
            layer = Image.new('RGBA', im.size, (0, 0, 0, 0))
            position = (im.size[0] - mark.size[0], im.size[1] - mark.size[1])
            layer.paste(mark, position)
            Image.composite(layer, im, layer).save(join(outfolder, name), format="JPEG")

start()

Водяной знак на картинки в папке