1. Yes, parse_render() need raise UnsupportedImageFormat to  limit available image formats, but here also need raise it, because we need catch PIL/Pillow errors.
2. `pip install pillow`, then `yum remove libjpeg`. It will raise `ImportError: The _imaging C module is not installed`

BTW. I forgot catch `IOError: encoder jpeg not available` . <(づ∥￣▽￣)>