Download presentation
Presentation is loading. Please wait.
Published byJoel Newman Modified over 9 years ago
1
Auto-regressive dynamical models Continuous form of Markov process Linear Gaussian model Hidden states and stochastic observations (emissions) Statistical filters: Kalman, Particle EM learning Mixed states
2
Configuration AR model Parametric shape/texture model, eg curve model: Auto-regressive dynamical model driven by independent noise ARP order possibly nonlinear
3
Deformable curve model Planar affine + learned warps Active shape models (Cootes&Taylor, 93) Residual PCA (“Active Contours”, Blake & Isard, 98) Active appearance models (Cootes, Edwards &Taylor, 98) curve model:
4
Configuration Linear Gaussian AR model Prior shape “Steady state” prior Linear AR model (“Active Contours”, Blake and Isard, Springer 1998) (1 st order)
5
Gaussian processes for shape & motion intra-classsingle object (Reynard, Wildenberg, Blake & Marchant, ECCV 96)
6
Stochastic observer Kalman filter (Forward filter) Kalman smoothing filter (Forward-Backward) Kalman filter independent noise (Gelb 74) alsoetc.
7
Classical Kalman filter
8
Visual clutter
9
Visual clutter observational nonlinearity
10
Particle Filter: Non-Gaussian Kalman filter www.research.microsoft.com/~ablake/talks/MonteCarlo.ppt
11
Particle Filter (PF) continue
12
particles “sprayed” along the contour “JetStream”: cut-and-paste by particle filtering
13
Propagating Particles particles “sprayed” along the contour particles “sprayed” along the contour contour smoothness prior contour smoothness prior
14
Branching
15
MLE Learning of a linear AR Model Direct observations: “Classic” Yule-Walker Learn parameters by maximizing: which for linear AR process minimizing Finally solve: where “sufficient statistics” are:
16
Handwriting -- simulation of learned ARP model “Scribble” -- disassembly
17
Simulation of learned Gait -- simulation of learned ARP model
18
Walking Simulation (ARP)
19
Walking Simulation (ARP + HMM) (Toyama & Blake 2001)
20
Dynamic texture (S. Soatto, G. Doretto, Y. N. Wu, ICCV 01; A. Fitzgibbon, ICCV01)
21
Speech-tuned filter (Blake, Isard & Reynard, 1985)
22
EM learning Stochastic observations z:unknown -- hidden unavailable – classic EM: M-step E-step i.e. FB smoothing
23
PF: forward only
24
PF: forward-backward continue
25
Juggling (North et al., 2000)
26
State lifetimes and transition rates also learned Learned Dynamics of Juggling
27
Juggling
28
Perception and Classification Ballistic (left)Catch, carry, throw (left)
29
Underlying classifications
30
Learning Algorithms EM-P
31
1D Markov models 1D Markov models 2D Markov models
32
EM-PF Learning Forward-backward particle smoother (Kitagawa 96, Isard and Blake, 98) for non-Gaussian problems:particle smoother Generates particles with weights Autocorrelations: Transition Frequencies:
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.