from PIL import Image
from pathlib import Path

source = ''
target = ''

for image in Path(source).glob('*.jpg'):

    img = Image.open(image)
    width, height = img.size

    if height > width:
        var = height / width
        new_width = int(1600 / var)
        new_height = 1600
    else:
        var = width / height
        new_width = 1600
        new_height = int(1600 / var)

    img_final = img.resize((new_width, new_height))
    img_final.save(target + '\\' + image.name, quality=85)
    print(f'file{image} ok!')