script for batch fixing image dimensions

fix_images.py

#!/usr/bin/env python3
# fix_images.py
# author: bruno borges paschoalinoto
# no rights reserved
# written for my friend @LucasGiannella

import sys, os, math
from itertools import repeat

try:
  from PIL import Image
except:
  print("Pillow does not seem to be installed. Try running:")
  print("  python3 -m pip install --upgrade Pillow")
  print("to install it.")
  sys.exit(1)

EXTS = [
  ".jpg", ".jpeg", ".png", ".gif", ".tiff", ".tif", ".bmp", ".dib"
]


def fiximg(args):
  fn, target_dim = args
  img = Image.open(fn)
  corrs = []
  if img.size[0] < img.size[1]:
    corrs.append("rotation")
    img = img.rotate(90)
  w, h = img.size
  wj, hj = target_dim
  if w < wj:
    corrs.append("stretch to fit width")
    img = img.resize((wj, h*wj//w))
  w, h = img.size
  if h < hj:
    corrs.append("stretch to fit height")
    img = img.resize((w*hj//h, hj))
  w, h = img.size
  if (w, h) != (wj, hj):
    left = (w - wj)//2
    top = (h - hj)//2
    right = (w + wj)//2
    bottom = (h + hj)//2
    img = img.crop((left, top, right, bottom))
    corrs.append("center cut")
  if len(corrs):
    img.save(fn)
    s = ", ".join(corrs)
    print(f"Image {fn} required: {s}.")
    return True
  else:
    print(f"Image {fn} was already the right size.")
    return False


def fixdir(dirpath, target_dim, num_threads=1):
  print(f"Fixing images in {dirpath} with {num_threads} threads.\n")
  isimg = lambda p: any([ext in p for ext in EXTS])
  fs = map(lambda f: os.path.join(dirpath, f), os.listdir(dirpath))
  imgs = list(zip(filter(isimg, fs), repeat(target_dim)))
  if num_threads == 1:
    my_map = map
  else:
    from multiprocessing import Pool
    my_map = Pool(num_threads).map
  total = sum(my_map(fiximg, imgs))
  print(f"\nDone! Saw {len(imgs)} images, {total} out of which were changed.")
  return total


def main(argc, argv):
  if argc < 4:
    print("Specify directory, width and height.")
    return 1
  _, dirpath, wj, hj = argv[:4]
  try:
    wj = int(wj)
    hj = int(hj)
    if wj < 1 or hj < 1:
      raise ValueError("Width and height need both be POSITIVE integers.")
  except ValueError as ve:
    print(ve)
    return 1
  try:
    from multiprocessing import cpu_count
    cc = cpu_count()
  except:
    cc = 1
  num_threads = (cc - 1) if cc > 1 else 1
  fixdir(dirpath, (wj, hj), num_threads=num_threads)
  return 0


if __name__ == "__main__":
  from sys import argv, exit
  exit(main(len(argv), argv))