What kind of quality do you need and how many angles of the same picture do you get?

If you only get one angle, and quality isn't extremely important, it would be easy enough to map a person's ID to a 3d head. As far as heads go, you can assume an average shape and size that you would just paste the image on. The nose would be kind of a lump, not really defined, and you'd stretch the edge of the picture so that it curves correctly around the face.

If you get multiple angles, like the front and sides, you can use the same "average" head but paste the seperate images onto portions of the head. Where the images meet, you'd use a little alpha blending or line matching to get things to look right. The good thing about multiple angles is that you could get the outline of the head just right using the side view. If you can find the outline of the nose, then you have a good idea of where the eyes are and the whole thing kinda falls together.