Publications de Samy Bengio | EPFL Graph Search

Discriminative Keyword Spotting

2009

A Discriminative Kernel-based Model to Rank Images from Text Queries

This paper introduces a discriminative model for the retrieval of images from text queries. Our approach formalizes the retrieval task as a ranking problem, and introduces a learning procedure optimizing a criterion related to the ranking performance. The ...

2008

A Kernel Trick For Sequences Applied to Text-Independent Speaker Verification Systems

Samy Bengio

This paper present a principled SVM based speaker verification system. We propose a new framework and a new sequence kernel that can make use of any Mercer kernel at the frame level. An extension of the sequence kernel based on the Max operator is also pro ...

2007

Performance Generalization in Biometric Authentication Using Joint User-Specific and Sample Bootstraps

Samy Bengio, Norman Hoon Thian Poh

Biometric authentication performance is often depicted by a DET curve. We show that this curve is dependent on the choice of samples available, the demographic composition and the number of users specific to a database. We propose a two-step bootstrap proc ...

2007

On transforming statistical models for non-frontal face verification

Samy Bengio

2006

Using Chimeric Users to Construct Fusion Classifiers in Biometric Authentication Tasks: An Investigation

Samy Bengio, Norman Hoon Thian Poh

Chimeric users have recently been proposed in the field of biometric person authentication as a way to overcome the problem of lack of real multimodal biometric databases as well as an important privacy issue -- the fact that too many biometric modalities ...

IEEE2006

Measuring the Performance of Face Localization Systems

Yann Rodriguez, Samy Bengio

The purpose of Face localization is to determine the coordinates of a face in a given image. It is a fundamental research area in computer vision because it serves, as a necessary first step, any face processing systems, such as automatic face recognition, ...

2006

Database, Protocol and Tools for Evaluating Score-Level Fusion Algorithms in Biometric Authentication

Samy Bengio, Norman Hoon Thian Poh

Fusing the scores of several biometric systems is a very promising approach to improve the overall system's accuracy. Despite many works in the literature, it is surprising that there is no coordinated effort in making a benchmark database available. It sh ...

2006

User Authentication via Adapted Statistical Models of Face Images

Samy Bengio

2005

How Do Correlation and Variance of Base-Experts Affect Fusion in Biometric Authentication Tasks?

Samy Bengio, Norman Hoon Thian Poh

Combining multiple information sources such as subbands, streams (with different features) and multi modal data has shown to be a very promising trend, both in experiments and to some extend in real-life biometric authentication applications. Despite consi ...

2005

Online Policy Adaptation for Ensemble Classifiers

Samy Bengio, Christos Dimitrakakis

Ensemble algorithms can improve the performance of a given learning algorithm through the combination of multiple base classifiers into an ensemble. In this paper we attempt to train and combine the base classifiers using an adaptive policy. This policy is ...

2005

Automatic Analysis of Multimodal Group Actions in Meetings

Samy Bengio, Mark Barnard, Guillaume Lathoud, Dong Zhang, Daniel Gatica-Perez

This paper investigates the recognition of group actions in meetings. A statistical framework is proposed in which group actions result from the interactions of the individual participants. The group actions are modelled using different HMM-based approache ...

2005

A Unified Framework for Score Normalization Techniques Applied to Text Independent Speaker Verification

Samy Bengio

The purpose of this paper is to unify several of the state-of-the-art score normalization techniques applied to text-independent speaker verification systems. We propose a new framework for this purpose. The two well-known Z- and T-normalization techniques ...

IEEE Institute of Electrical and Electronics Engineers2005