REALTIME SPEAKER IDENTIFICATION FOR VIDEO CONFERENCING Automatic speaker identification in a videoconferencing environment will allow conference attendees to focus their attention on the conference rather than having to be engaged manually in identifying which channel is active and who may be the speaker within that channel. In this work we present a realtime, audiocoupled video based approach to address this problem, but focus more on the video analysis side. The system is driven by the need for detecting a talking human via the use of computer vision algorithms. The initial stage consists of a face detector which is subsequently followed by a liplocalization algorithm that segments the lip region. A novel approach for lip movement detection based on image registration and using the Coherent Point Drift (CPD) algorithm is proposed. Coherent Point Drift (CPD) is a technique for rigid and nonrigid registration of point sets. We provide experimental results to analyse the performance of the algorithm when used in monitoring real life videoconferencing data.

ACOUSTICLABIAL SPEAKER VERIFICATION This paper describes a multimodal approach for speaker verification. The system consists of two classifiers, one using visual features and the other using acoustic features. A lip tracker is used to extract visual information from the speaking face which provides shape and intensity features. We describe an approach for normalizing and mapping different modalities onto a common confidence interval. We also describe a novel method for integrating the scores of multiple classifiers. Verification experiments are reported for the individual modalities and for the combined classifier. The performance of the integrated system outperformed each subsystem and reduced the false acceptance rate of the acoustic subsystem from 2.3% to 0.5%.