As far as i know there's no way to do it easily. There are programs that can detect and try to figure out shape and letters but even then you'd need to do tweaking over and over.
second guy's post. (on second look, the entire comments may help you rather than just the one comment)
http://typophile.com/node/94121
second guy's post. (on second look, the entire comments may help you rather than just the one comment)
http://typophile.com/node/94121