Automatically turning photos into 3d models is almost impossible, at least for characters. There are some programs that work for simple geometry, but not something complex like a 3d character model.
What you could do is creating textures from the photos you have and apply them to your 3d models. In Poser for example this is easy with the face editor, the results look ok. From Poser you can easily export 3d-sprites of you characters then, but you can't use the models itself for a 2.5d game because they are way to high-poly.
If you are good at low-poly modelling you could do the same for realtime 3d models of course. Most modelling programs can export 2d images, too.