Extraction of key frames from videos by optimal color composition matching and polygon simplification

A video sequence is first mapped to a sequence of points in a semi-metric space that forms a polyline. We require only that a semi-distance between pairs of points be defined that need not satisfy the triangle inequality. By simplifying the polyline, we obtain a small set of the most relevant key frames that is representative of the whole video sequence. The degree of the simplification is either determined automatically or selected by the user. Using our technique, a viewer can browse a video at the level of summarization that suits his patience level. Applications include the creation of a smart fast-forward function for digital VCRs, and the automatic creation of short summaries or trailers that can be used as previews before videos are downloaded from the web.