import os
from PIL import Image
imdir = "directory of images"
savedir="path to where you wanna save the files"
files = [os.path.join(imdir, fname) for fname in os.lsdir(imdir)]
for infile in files:
    im = pil.Image.open(infile)
    file, ext = os.path.splitext(infile)
    //first region
    slice1 = im.crop((left, upper, right, lower)
    slice.save(file+"slice1", "JPEG")
   //copy and paste with new boxes