[Cole Johnson]

Hey! No clue if you’re still checking this thread, but just in case I figure I’ll attempt to help.

If you still happen to have the original PSD file, simply create a new PSD with the same aspect ratio as the original and copy the old photo into the new file, resizing it to fit the larger size.

Luckily, Photoshop doesn’t add anti-aliasing, so this is the best way to get a larger file of a bitmap.

Either that, or I’m fairly certain you can trace it in Illustrator.

Never used Illustrator extensively before, however, and am not 100% sure on that one.