TY - GEN
T1 - Robust multi-modal group action recognition in meetings from disturbed videos with the asynchronous Hidden Markov model
AU - Al-Hames, Marc
AU - Lenz, Claus
AU - Reiter, Stephan
AU - Schenk, Joachim
AU - Wallhoff, Frank
AU - Rigoll, Gerhard
PY - 2007
Y1 - 2007
N2 - The Asynchronous Hidden Markov Model (AHMM) models the joint likelihood of two observation sequences, even if the streams are not synchronised. We explain this concept and how the model is trained by the EM algorithm. We then show how the AHMM can be applied to the analysis of group action events in meetings from both clear and disturbed data. The AHMM outperforms an early fusion HMM by 5.7% recognition rate (a rel. error reduction of 38.5%) for clear data. For occluded data, the improvement is in average 6.5% recognition rate (rel. error red. 40%). Thus asynchronity is a dominant factor in meeting analysis, even if the data is disturbed. The AHMM exploits this and is therefore much more robust against disturbances.
AB - The Asynchronous Hidden Markov Model (AHMM) models the joint likelihood of two observation sequences, even if the streams are not synchronised. We explain this concept and how the model is trained by the EM algorithm. We then show how the AHMM can be applied to the analysis of group action events in meetings from both clear and disturbed data. The AHMM outperforms an early fusion HMM by 5.7% recognition rate (a rel. error reduction of 38.5%) for clear data. For occluded data, the improvement is in average 6.5% recognition rate (rel. error red. 40%). Thus asynchronity is a dominant factor in meeting analysis, even if the data is disturbed. The AHMM exploits this and is therefore much more robust against disturbances.
KW - Hidden Markov models
KW - Meetings
KW - Multimedia communication
KW - Robustness
KW - Video signal processing
UR - http://www.scopus.com/inward/record.url?scp=48149111986&partnerID=8YFLogxK
U2 - 10.1109/ICIP.2007.4379130
DO - 10.1109/ICIP.2007.4379130
M3 - Conference contribution
AN - SCOPUS:48149111986
SN - 1424414377
SN - 9781424414376
T3 - Proceedings - International Conference on Image Processing, ICIP
SP - II213-II216
BT - 2007 IEEE International Conference on Image Processing, ICIP 2007 Proceedings
T2 - 14th IEEE International Conference on Image Processing, ICIP 2007
Y2 - 16 September 2007 through 19 September 2007
ER -