An earlier post about the independent feature "Able Edwards" made reference to the use of scanned photos that were manipulated in Photoshop to produce new environments for the actors to be composited against. If you're interested in how such an effect is achieved, you might want to check out the links below. There are two tutorials on creating a digital matte painting which take you step-by-step through the process, from finding source images on the Web to adding realistic details and lighting.
The use of matte paintings goes back to the early days of film production when mattes were painted on glass and then shot live. Using matte paintings made it possible to add production value to films by making it appear as if a special set was in place when all that existed was paint. The advent of producing images digitally puts the power of big production values within the reach of those without the budget to hire a skilled painter. While a certain level of skill and craftsmanship is still required, often only basic manipulation of existing images is required to create a new location or world.
Matte Painting for Film and Television by Dennis Sedov
Matte Painting - The Castle by Dragos Jieanu
