I just finished this in the lab a little while ago and have a monster migraine now. haha.
Done in Painter with lots and lots of chalks, airbrushes, sponges, and pastels.
We basically clone the original image, backspace, and use the light box and stamp color tool to create a painting of a photo. This is one of my favorite art pieces because I started with no idea of how I was going to do this and ended up playing around with different brushes and layers to end up with a product I really love. Ahh art is amazing. :)