TY - GEN
T1 - Sampling methods for unsupervised learning
AU - Fergus, Rob
AU - Zisserman, Andrew
AU - Perona, Pietro
PY - 2005
Y1 - 2005
N2 - We present an algorithm to overcome the local maxima problem in estimating the parameters of mixture models. It combines existing approaches from both EM and a robust fitting algorithm, RANSAC, to give a data-driven stochastic learning scheme. Minimal subsets of data points, sufficient to constrain the parameters of the model, are drawn from proposal densities to discover new regions of high likelihood. The proposal densities are learnt using EM and bias the sampling toward promising solutions. The algorithm is computationally efficient, as well as effective at escaping from local maxima. We compare it with alternative methods, including EM and RANSAC, on both challenging synthetic data and the computer vision problem of alpha-matting.
AB - We present an algorithm to overcome the local maxima problem in estimating the parameters of mixture models. It combines existing approaches from both EM and a robust fitting algorithm, RANSAC, to give a data-driven stochastic learning scheme. Minimal subsets of data points, sufficient to constrain the parameters of the model, are drawn from proposal densities to discover new regions of high likelihood. The proposal densities are learnt using EM and bias the sampling toward promising solutions. The algorithm is computationally efficient, as well as effective at escaping from local maxima. We compare it with alternative methods, including EM and RANSAC, on both challenging synthetic data and the computer vision problem of alpha-matting.
UR - http://www.scopus.com/inward/record.url?scp=84898968638&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84898968638&partnerID=8YFLogxK
M3 - Conference contribution
AN - SCOPUS:84898968638
SN - 0262195348
SN - 9780262195348
T3 - Advances in Neural Information Processing Systems
BT - Advances in Neural Information Processing Systems 17 - Proceedings of the 2004 Conference, NIPS 2004
PB - Neural information processing systems foundation
T2 - 18th Annual Conference on Neural Information Processing Systems, NIPS 2004
Y2 - 13 December 2004 through 16 December 2004
ER -