I'm afraid I don't understand the question. Do you wish to alter the size of the image itself, or the alter the size of the subjects within the image? Either way, it can be done in Photoshop without need of further software. That is, of course, presuming you own a copy of Photoshop.
-Medley.
There are only 10 types of people in this world- those who understand binary, and those who don't.