from PIL import Image

def make_square(im, min_size=256, fill_color=(255, 255, 255)):
    x, y = im.size
    size = max(min_size, x, y)
    new_im = Image.new('RGBA', (size, size), fill_color)
    new_im.paste(im, (int((size - x) / 2), int((size - y) / 2)))
    return new_im

import os
import shutil

formats = ('jpg', 'jpeg', 'png', 'jtif', 'webp')
folder = 'D:/picures/' #root folder
src = folder+'photos' #pictures to rectify
dest = folder+'photos_rect' #rectified picture folder

for root, dirs, files in os.walk(src):
    for file in files:
        if file.lower().endswith(formats):
            DEST = f"{dest}/{root[3:]}"
            if not os.path.exists(DEST):
                os.makedirs(DEST)
            shutil.copy(os.path.join(root, file), os.path.join(DEST, file))


for root, dirs, files in os.walk(dest):
    for file in files:
        path = os.path.join(root, file)
        im = Image.open(path)
        im = make_square(im)
        im = im.convert('RGB')
        im.save(path, 'JPEG')