*Title:*Latent identity variables for face recognition: from distance based methods to probabilistic inference

*Speaker:*Dr. Simon Prince
Department of Computer Science
UniversityCollegeLondon(UCL)

*Place: *room 209, Electronic Engineering

*Date: *Wednesday 25 July

*Time: *1 pm

*Abstract:*Many face recognition algorithms use “distance-based”
methods: feature vectors are extracted from each face and distances in
feature space are compared to determine matches. In this paper we argue
for a fundamentally different approach. We consider each image as having
been generated from an underlying cause (a latent identity variable, or
LIV). In recognition we evaluate the probability that two faces have the
same underlying cause. Since image generation is noisy, we can never be
exactly certain what this cause was, so we integrate (marginalize) over
all possible causes. We present examples of identification and
verification and show that the LIV approach outperforms equivalent
distance-based algorithms. Moreover, other advantages include: (i) a
natural approach to changes in pose and lighting (ii) the ability to
implement novel algorithms that have no distance-based equivalent (iii)
a principled way to combine multiple observations and prior information.

*About the speaker:*Dr. Simon Princeisa lecturer in the Department of
Computer Science at University College London.Hewas an undergraduate at
UCL where he studied Psychology. His doctoral work was at the
Universityof Oxford, in the Department of Experimental Psychology. He
subsequently worked in the Laboratory of Physiology in Oxfordfor two
years as Post Doc with Andrew Parker. In 2000 he returned to UCL where
he undertook the Masters by Research in Computer Vision, Image
Processing, Graphics and Simulation. Upon completion of this degree he
moved for two and a half years to Singaporewhere he was a post-doctoral
research fellow in the Department of Electrical and Computer Engineering
in the National University of Singapore. Following this, he moved to
Toronto, Canada, where he worked as a post-doc for James Elder in the
Centre for Vision Research in YorkUniversityuntil 2005.