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Andrzej Drygajlo

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Related publications (26)

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Bayesian Networks Based Multimodality Fusion for Error Handling in Human-Robot Dialogues Under Noisy Conditions

Andrzej Drygajlo, Plamen Prodanov

In this paper, we introduce probabilistic model based architecture for error handling in human–robot spoken dialogue systems under adverse audio conditions. In this architecture, a Bayesian network framework is used for interpretation of multi-modal signal ...

2005

Promoting diversity in Gaussian mixture ensembles: an application to signature verification

Jonas Richiardi, Andrzej Drygajlo

Classifiers based on Gaussian mixture models are good performers in many pattern recognition tasks. Unlike decision trees, they can be described as stable classifier: a small change in the sampling of the training set will produce not a large change in the ...

Springer2008

Identification of Aging Faces using A-stack Classification Model

Andrzej Drygajlo, Weifeng Li

The problem of time validity of biometric models has received only a marginal attention from researchers. In this paper, we investigate the aging influence on the classifier scores of genuine client. Our studies show that as age progresses the classifier s ...

Ieee Service Center, 445 Hoes Lane, Po Box 1331, Piscataway, Nj 08855-1331 Usa2009

Speaker verification in score-ageing-quality classification space

Andrzej Drygajlo, Finnian Paul Kelly

A challenge in automatic speaker verification is to create a system that is robust to the effects of vocal ageing. To observe the ageing effect, a speaker's voice must be analysed over a period of time, over which, variation in the quality of the voice sam ...

Academic Press Ltd- Elsevier Science Ltd2013

Discarding low quality Minutia Cylinder-Code pairs for improved fingerprint comparison

Andrzej Drygajlo, Mohammad Hamed Izadi

Local minutiae descriptors such as Minutia Cylinder-Code (MCC) are becoming more popular in modern fingerprint matching systems. The matching performance depends a lot on the fingerprint image quality in global and local levels. Rejecting part of the lowes ...

2015

The Multiscenario Multienvironment BioSecure Multimodal Database (BMDB)

Norman Hoon Thian Poh, Jonas Richiardi, Andrzej Drygajlo

A new multimodal biometric database designed and acquired within the framework of the European BioSecure Network of Excellence is presented. It is comprised of more than 600 individuals acquired simultaneously in three scenarios: 1) over the Internet, 2) i ...

2010

Forensic Automatic Speaker Recognition

Andrzej Drygajlo

The existence of highly developed and fully automated telephone networks in industrialized countries and the pervasiveness of speech communication technology have resulted in the ever-increasing use of the human voice as an instrument in the commission of ...

2007

Low-level grounding in a multimodal mobile service robot conversational system using graphical models

Jonas Richiardi, Andrzej Drygajlo, Plamen Prodanov, Anil Alexander

The main task of a service robot with a voice-enabled communication interface is to engage a user in dialogue providing an access to the services it is designed for. In managing such interaction, inferring the user goal (intention) from the request for a s ...

Springer-Verlag2008

Aural and automatic forensic speaker recognition in mismatched conditions

Andrzej Drygajlo, Anil Alexander

In this article, we compare aural and automatic speaker recognition in the context of forensic analyses, using a Bayesian framework for the interpretation of evidence. We use perceptual tests performed by non-experts and compare their performance with that ...

2005

Improving biometric verification with class-independent quality information

Andrzej Drygajlo

Existing approaches to biometric classification with quality measures make a clear distinction between the single-modality applications and the multi-modal scenarios. This study bridges this gap with Q-stack, a stacking-based classifier ensemble, which use ...

2009

Verification of Aging Faces Using Local Ternary Patterns and Q-Stack Classifier

Weifeng Li, Andrzej Drygajlo

This paper deals with the influence of age progression on the performance of face verification systems. This is a challenging and largely open research problem that deserves more and more attention. Aging affects both the shape of the face and its texture, ...

Springer2009

On Quality of Quality Measures for Classification

Andrzej Drygajlo

In this paper we provide a theoretical discussion of the in)pact of uncertainty in quality measurement oil the expected benefits of including biometric signal quality measures in classification. While all ideal signal quality measure should be a, precise q ...

Springer-Verlag New York, Ms Ingrid Cunningham, 175 Fifth Ave, New York, Ny 10010 Usa2008

Embedding cylinder quality measures into Minutia Cylinder-Code based latent fingerprint matching

Andrzej Drygajlo, Mohammad Hamed Izadi

One of the major problems concerning latent fingerprint matching in forensic applications is the poor quality of fingerprint data. Therefore, local quality assessment of fingerprint images is necessary to ensure high biometric performance in this applicati ...

ACM Press2012

How synthetic fingerprints can improve pre-selection of MCC pairs using local quality measures

Andrzej Drygajlo, Mohammad Hamed Izadi

A major source of errors in fingerprint recognition systems is poor quality of fingerprints. Local quality of fingerprints plays an important role in these systems to ensure high recognition performance. Recently an improved fingerprint matching method is ...

2015

Palm vein recognition with local texture patterns

Andrzej Drygajlo, Leila Mirmohamadsadeghi

Biometric recognition using the palm vein characteristics is emerging as a touchless and spoof-resistant hand-based means to identify individuals or to verify their identity. One of the open challenges in this field is the creation of fast and modality-dep ...

Inst Engineering Technology-Iet2014

Client-specific A-stack model for adult face verification across aging

Andrzej Drygajlo, Weifeng Li

The problem of time validity of biometricmodels has received only a marginal attention from researchers. In this paper, we propose to manage the aging influence on the adult face verification system by an A-stack age modeling technique, which uses the age ...

2011

Reliability-based decision fusion in multimodal biometric verification systems

Jonas Richiardi, Andrzej Drygajlo, Plamen Prodanov

We present a methodology of reliability estimation in the multimodal biometric verification scenario. Reliability estimation has shown to be an efficient and accurate way of predicting and correcting erroneous classification decisions in both unimodal (spe ...

2007

Credence estimation and error prediction in biometric identity verification

Andrzej Drygajlo

This paper focuses on the estimation of credence in the correctness of classification decisions produced by a biometric identity verification system. We adopt the concept of decision credence defined in terms of subjective Bayesian degree of belief. We dem ...

2008

Biometrics for Identity Documents and Smart Cards: European Perspective

Andrzej Drygajlo

With an increase in identity fraud and the emphasis on security, there is a growing and urgent need to efficiently identify humans both locally and remotely on a routine basis. The appearance of biometric identity documents such as passports, visas, nation ...

2008

Confidence and Reliability Measures in Speaker Verification

Jonas Richiardi, Andrzej Drygajlo, Plamen Prodanov

Speaker verification is a biometric identity verification technique whose performance can be severely degraded by the presence of noise. Using a coherent notation, we reformulate and review several methods which have been proposed to quantify the uncertain ...

2006