split_img.py

from pathlib import Path

import cv2
import numpy as np

from tqdm import tqdm


def main(filename):
    # 画像を読み込む
    img = cv2.imread(filename)
    assert img is not None, f'Cannot open {filename}'

    # フォルダの作成
    dst_filename_stem = Path(filename).stem
    (Path('.') / dst_filename_stem).mkdir()

    # 画像のリサイズ
    height, width, _ = img.shape
    img = cv2.resize(img, (width//4, height//4))

    # 画像の分割 & 保存
    strips = np.split(img, 12, axis=1)
    for i in range(8):
        work = strips[i:] + strips[:i]
        dst = np.hstack(work)

        cv2.imwrite(f'{dst_filename_stem}/{i:02d}.jpg', dst)


if __name__ == '__main__':
    root = Path(r'...')

    for img_file in tqdm(root.glob('*/*.jpg')):
        img_file = str(img_file.resolve())
        main(img_file)