Eigenfeatures coding of videoconferencing sequences

This paper presents a video coding techique that achieves high visual quality at very low bit rates. Each video frame is divided into two regions, consisiting of a background area and a visually important feature to be coded at higher bit rates. The feature is tracked from frame to frame and it is coded using a set of features that are extracted from a training set. The set of features, which will be referred to as eigenfeatures, is stored both at the encoder and decoder sites. The technique is based on the eigenfaces method proposed in [1], and achieves high visual quality at high feature compression ratios (around 200 for the salesman sequence and 1000 for the Miss America sequence) with considerably less computational complexity than the eigenfaces method. Using this technique for the feature together with H.261 for the background allows a reduction of up 70% in the bit rate compared to using H.261 alone.