The Cartoon Filter in After Effects CS4 allows users to create a wide range of video stylization effects, from a pencil-like black-and-white look, to flat colors with edges, similar to the movie Waking Life or A Scanner Darkly. Unlike those movies, the filter does not employ manual rotoscoping, but instead relies on several image filters to achieve real-time performance.
Under the hood, the Cartoon Filter is implemented as a PixelBender graph. As one of the first Pixelbender video filters (and a fairly complex one at that), the Cartoon Filter was used internally to stress-test and showcase Pixelbender technology.
The technical aspects (and some interesting perceptual motivations) for the Cartoon Filter were developed externally at Northwestern University, and published at SIGGRAPH 2006.
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