Robust dominant motion estimation using MPEG information in sport sequences

In this paper, we introduce a new method to estimate a parametric description of the dominant motion existing in a video sequence, a key task needed to face more complex video analysis problems. In order to do so, we use motion data provided by the MPEG streams. We propose a method based on imaginary straight line tracking to retrieve the projective transformations that describe the dominant motion of a sequence by estimating 2-D homographies. Our method takes advantage not only of the MPEG motion data, but also of its structure. In order to overcome the noise introduced by the MPEG compression scheme, we also employ several robust estimators to attain reliability. We demonstrate its performance by displaying several image mosaics derived from the motion in real time. Index Terms--Compressed-domain analysis, dominant motion estimation, MPEG transcoding, robust registration, video summarization.