Check out this page about the Starn Twins, two brothers who create mixed media art by altering and collaging photographic prints. Then google them to see more examples of their work!
Gerhard Richter : Overpainted Photographs
Evidence of editing after the image has been processed.
Mike and Doug Starn *~twinz~* identical liked the theme of doubling, because..they are..twins. influenced by science, physics, light, photographing and then rethinking and reworking things from an art historical standpoint.
Layered Landscapes by Nobuhiro Nakanishi
YellowRose | Mike + Doug Starn | 1982-1986
Shards of Memory: David Prifti, by Jason Landry via Huffington Post.