Compressed domain action classification using HMM

This paper proposes three techniques of feature extraction for person independent action classification in compressed MPEG video. The features used are extracted from motion vectors, obtained by partial decoding of the MPEG video. The feature vectors are fed to Hidden Markov Model (HMM) for classification of actions. Totally seven actions were trained with distinct HMM for classification. Recognition results of more than 90% have been achieved. This work is significant in the context of emerging MPEG-7 standard for video indexing and retrieval. (C) 2002 Elsevier Science B.V. All rights reserved.