Python PIL：裁剪多个图像会导致冻结和 memory 泄漏

Question

I'm trying to crop multiple images (thousands) with PIL and saving the result to the disk. However, after just cropping a few 100 images and saving them successfully, the program uses 17.5 GB of RAM and takes forever to create the next crop. After that, it only outputs two more images with a size of 65535×65535 pixels each (the original images are all 1920x1080) and then the loop is done.

My code:

import PIL
from PIL import Image
PIL.Image.MAX_IMAGE_PIXELS = 4294836225

for path in paths:
   with Image.open(path) as img:
      left, top, right, bottom = calculate_crop(...)
      cropped = img.crop((left, top, right, bottom))
      cropped.save(new_path, 'png')
      cropped.close()

No exception is ever fired (I also tried using try/except). Do I do something wrong here or could this be a bug in the library?

Answer 1

Okay according to PIL memory leak github forum the issue is that the handler stops calling the.close() method on the file or at least doesn't do it immediately. I would suggest manually opening and closing the file yourself. This may only resolve part of the issue however.