python HEIC2jpg compression

I was sorting through photos recently and found that HEIC photos taken with mobile phones are not supported by computers; the files are too large, and photos taken casually do not require high resolutions.
Find a HEIC converter available for win https://imagemagick.org/script/convert.php, and add a compression code

import os
import time
import math
from PIL import Image

def compress_jpg(file, min_size=1920):
    sImg = Image.open(file)
    h, w = sImg.size
    max_ori, min_ori = max(h, w), min(h, w)
    if min_ori <= min_size: return
    size = (math.floor(max_ori / min_ori * min_size), min_size)  # 横板
    if h < w: size = (size[1], size[0])  # 竖版
    dImg = sImg.resize(size, Image.ANTIALIAS)  
    dImg.save(file) 

def heic2jpg(file):
    assert os.path.exists(file)
    img = file[:-4] + 'jpg'
    os.system(f'/path/to/convert {file} {img}')
    time.sleep(0.2)
    assert os.path.exists(img)
    return img

def main(root_dir, keep=False):
    for root, dirs, files in os.walk(root_dir):
        for file in files:
            file = os.path.join(root, file)
            if file.lower().endswith('.heic'):
                print(file)
                compress_jpg(heic2jpg(file))
                if not keep:
                    os.remove(file)

if __name__ == "__main__":
    main_with_accelerate('A:\\pictures')