Get image type

getimagetype.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-

def get_image_type(filename):
    with open(filename, 'rb') as f:
        data = f.read(10).encode('hex')
        ftype = None
        if data.startswith('ffd8'):
            ftype = 'jpeg'
        elif data.startswith('474946'):
            ftype = 'gif'
        elif data.startswith('89504e470d0a1a0a'):
            ftype = 'png'
        elif data.startswith('424d'):
            ftype = 'bmp'
        return ftype
 
import sys

if __name__ == '__main__':
    for f in sys.argv[1:]:
        print '%s: %s' % (f, get_image_type(f))