Our friends at JaegerSloan recently came looking for a way to dynamically light a greenscreen shoot using realtime color information from the background video. With a system like that, they figured, they could match lighting without having to do much in post. It was a good idea.
The content was a Foursquare spot, the foreground subject was a hand holding a smartphone, and the composited background was all stock footage.
To make this happen, I whipped up a simple system allows the user to click points on the background video to define an arbitrary number of pixels from which to sample color. It then pipes that color information out to an arbitrary number of DMX lights.
Included in the interface is a preview of what's going out to each light as well as simple transport and looping controls for video playback.
Shutterstock did a little writeup -- check the video see a peek of it in action below.