Hello, friend! When memory card requires formatting, the stored information inside, like your photos, goes nowhere. It is still stored there and could be stayed there till you do write something new there.
So, in other words, as long as you do save no new stuff on this not formatted memory card, your pictures may be all restored there and only inaccessible.
To make them all visible and useful again, you can use some data recovery software to have a good try.
So, in your case, read more photo recovery articles here and see whether your pictures are still recoverable:
http://www.icare-recovery.com/howto/sd-card-photo-restore.html
Or http://en.wikipedia.org/wiki/Photo_recovery
