From: Kyle Schmitt <kyleaschmitt@...>
Date: 2009-06-19T01:51:20+09:00
Subject: Re: Mark GPS coordinates on image file

Err, I think you want something that does xmp or exif tagging.

ruby-exiv2 is supposed to be able to write out the tags, but I've not
done used it since I've only had to read.
For reading, exifr has been really great from my experience.

--Kyle