How can I re-categorize my posts as text, photo, link etc without re-posting?

Is there a way to change a "text" post into a "photo" post (or change posting categories in general) without deleting and re-posting?

I have a tumblr blog with something like 100 text posts with embedded photos. Is there a way to recategorize the posts as "photo" posts? I am interested in using a gallery-style tumblr theme which unfortunately, isn't compatible with text posts.

(my tumblr: http://www.doggiedrawings.net)