Digital Light & Color

Here is an academic paper, but with implementation too. The movie explains the practical use in photography at close to the end - I like the idea of reducing the whole implementation to 3 sliders...

http://www.cs.huji.ac.il/~danix/epd/index.html

And here is an implementation example from the paper. They split the flower image into 3 detail-scale components, whose contrast where adjusted individually and recombined.

http://www.cs.huji.ac.il/~danix/epd/MST ... index.html

Interesting - I'll take a closer look.