Convert image in .tif to png

tif_to_python.py

import sys
import os
from PIL import Image

def get_filename(filepath):
    filename = os.path.basename(filepath)
    filename, file_extension = os.path.splitext(filename)
    return filename

def convert_to_png(filepath):
    im = Image.open(filepath)
    im.thumbnail(im.size)
    filename = get_filename(filepath)
    im.save(filename + ".png", "PNG", quality=100)

if __name__ == '__main__':
    convert_to_png(sys.argv[1])