A simple command line python script which convert to grayscale and crop some image multiple times with the same size.

crop_image.py

import sys, getopt
import argparse
from PIL import Image

if __name__ == "__main__":
    parser = argparse.ArgumentParser()
    parser.add_argument('-i', '--image')
    parser.add_argument('-o', '--output')
    parser.add_argument('-d', '--divisor')
    args = parser.parse_args()

    try:
        divisor = int(args.divisor) if args.divisor else 4
    except:
        divisor = 4

    if args.image and args.output:
        with Image.open(args.image).convert('L') as im:
            w = im.width / divisor
            i = 1
            left = 0
            top = 0
            right = w
            bottom = im.height
            while i <= divisor:
                im.crop((left, top, right, bottom)).save("%s%s.jpg" % (args.output, i,))
                left += w
                right += w
                i += 1
    else:
        parser.print_help()