Edit: Damn new page, that up arrow is pointing to Rowlii's post
I have just pushed out RS Linkify Version 3.1.9.80 so the jpg:small, jpg:medium, etc should work with all supported image formats hosted on any domain
Latest version (3.1.9.80) is needed for the examples below to work.
Been a while since I have written any regex and I'm not going to lie, it left me scratching my head for a minute. I cracked it though, with the help of some strong coffee