Title
Combining Simple Models to Approximate Complex Dynamics
Abstract
Stochastic tracking of structured models in monolithic state spaces often requires modeling complex distributions that are difficult to represent with either parametric or sample-based approaches. We show that if redundant representations are available, the individual state estimates may be improved by combining simpler dynamical systems, each of which captures some aspect of the complex behavior. For example, human body parts may be robustly tracked individually, but the resulting pose combinations may not satisfy articulation constraints. Conversely, the results produced by full-body trackers satisfy such constraints, but such trackers are usually fragile due to the presence of clutter. We combine constituent dynamical systems in a manner similar to a Product of HMMs model. Hidden variables are introduced to represent system appearance. While the resulting model contains loops, making the inference hard in general, we present an approximate non-loopy filtering algorithm based on sequential application of Belief Propagation to acyclic subgraphs of the model.
Year
DOI
Venue
2004
10.1007/978-3-540-30212-4_9
Lecture Notes in Computer Science
Keywords
Field
DocType
complex dynamics,human body,belief propagation,dynamic system,satisfiability,hidden variables,state space
Complex dynamics,Mathematical optimization,Clutter,Inference,Filter (signal processing),Algorithm,Parametric statistics,Dynamical systems theory,Hidden variable theory,Mathematics,Belief propagation
Conference
Volume
ISSN
Citations 
3247
0302-9743
2
PageRank 
References 
Authors
0.47
16
3
Name
Order
Citations
PageRank
Leonid Taycher124019.37
John W. Fisher III287874.44
Trevor Darrell3224131800.67