I have created an Unpublished namespace on my wiki that is viewable only to certain users. The goal of this namespace is to have a place to create articles, so that I can time their release at which time I move the pages to the main namespace. So far this works well, except with images, which are of course in the special File namespace.

So basically, is there a way I can keep certain uploaded images hidden as well until I'm ready to release the article? I'd like something simple, I'm assuming with an extension.