I was working lately on a template on commons related to automatic overlay KML creation (see [1] for KML use on Commons). Two of the items I need but do not know how to access are full file dimensions in pixels and the url to the raw image (like [2]). I think with Lua, I can use HTML Parser [3] to parse the file page, but there must be a simpler way to access those.
Jarek T.
(user:jarekt http://commons.wikimedia.org/wiki/User:Jarekt )
[1] https://commons.wikimedia.org/wiki/Commons:Geocoding/Overlay
[2] https://upload.wikimedia.org/wikipedia/commons/3/36/Covington%2C_Indiana _map_from_1876_atlas.jpg