Indeed, you need only open Indeed, you need only open_file() (or open_datastream() if you use it) to extract metadata. unpack() only read and unpacks raw pixels, you do not need to use it if you need only metadata. Also, if you need thumbnail too, you may use open_file() + unpack_thumb() calls only. -- Alex Tutubalin @LibRaw LLC reply
Indeed, you need only open_file() (or open_datastream() if you use it) to extract metadata.
unpack() only read and unpacks raw pixels, you do not need to use it if you need only metadata.
Also, if you need thumbnail too, you may use open_file() + unpack_thumb() calls only.