你想要PIL它可以轻松地完成这个任务

You want PIL it does this with ease

from PIL import Image
sizes = [(120,120), (720,720), (1600,1600)]
files = ['a.jpg','b.jpg','c.jpg']

for image in files:
    for size in sizes:
      Image.open(image).thumbnail(size).save("thumbnail_%s_%s" % (image, "_".join(size)))

如果你迫切需要速度。然后编程，多处理或获取另一种语言。

If you desperately need speed. Then thread it, multiprocess it or get another language.