Automatic human face detection for content-based image annotation

In this paper, an automatic human face detection approach using colour analysis is applied for content-based image annotation. In the face detection, the probable face region is detected by adaptive boosting algorithm, and then combined with a colour filtering classifier to enhance the accuracy in face detection. The initial experimental benchmark shows the proposed scheme can be efficiently applied for image annotation with higher fidelity

Human gait recognition based on multiview gait sequences

Copyright © 2008 X. Huang and N. V. Boulgouris. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Most of the existing gait recognition methods rely on a single view, usually the side view, of the walking person. This paper investigates the case in which several views are available for gait recognition. It is shown that each view has unequal discrimination power and, therefore, should have unequal contribution in the recognition process. In order to exploit the availability of multiple views, several methods for the combination of the results that are obtained from the individual views are tested and evaluated. A novel approach for the combination of the results from several views is also proposed based on the relative importance of each view. The proposed approach generates superior results, compared to those obtained by using individual views or by using multiple views that are combined using other combination methods.European Commissio

Biometria e autenticação

Com a utilização cada vez maior de Tecnologias da Informação e das Comunicações (TIC) nos Sistemas de Informação (SI) das organizações, surgem com crescente evidência os problemas de segurança e, em particular, a questão da autenticação do utilizador. Esta questão é hoje fundamental já que o acesso indevido a informação sensível pode provocar grandes prejuízos à organização. Neste trabalho descreve-se uma das técnicas utilizadas na autenticação, a biometria, como forma de aumentar a qualidade da autenticação. Nesse sentido, é analisado o estado da arte, são identificadas algumas vantagens, desvantagens e limitações das principais tecnologias desenvolvidas e procura-se perceber o impacto que a autenticação biométrica pode ter nas organizações, quando conjugada com a tecnologia proporcionada pelos cartões com capacidade de processamento e armazenamento seguro, conhecidos como Smart Cards. Finalmente, é brevemente introduzido o projecto de investigação em curso para o desenvolvimento de um sistema que explora estas tecnologias

Оценка качества и идентификация отпечатков пальцев путем анализа структурных свойств изображения

The paper addresses the problem of assessing the quality of fingerprint images using spatial analysis methods. The author proposes using the previously developed mathematical model to describe the set of magnitudes of the image gradient. The model is based on the two-parameter Weibull distribution. The author proposes two approaches to assess the quality of fingerprints. The first approach is implemented by the so-called “Full reference method”, which compares the Weibull distribution parameters’ values of statistical estimates. The results of identifying sweat pores using this method are presented. The second approach is called the “No-Reference method” and is used to assess fingerprints’ quality when analyzing and identifying the information content of their individual sections. It is proposed to use an image blur map as a quality characteristic and a statistical estimate of the Weibull distribution shape parameter as a measure of the blur. The shape parameter is estimated at each image point by the combination of magnitudes of the image gradient in the vicinity of the point; in this, the previously developed blur mapping technique is applied. The specific examples illustrate effectiveness of the proposed approaches.Рассмотрена задача оценки качества изображения отпечатков пальцев с применением пространственных методов анализа. Предложено использовать математическую модель, разработанную ранее для описания совокупности магнитуд градиента изображения. Модель основана на двухпараметрическом распределении Вейбулла. Для оценки качества отпечатков пальцев предложены два подхода. Первый реализуется с помощью так называемого метода сравнения с эталоном (Full Reference), когда сравниваются значения статистических оценок параметров распределения Вейбулла. Приведены результаты решения задачи идентификации потовых пор этим методом. Второй подход называется «безэталонным» (No-Reference) и применяется для оценки качества отпечатков при анализе и выделении информативности их отдельных участков. В качестве характеристики качества предлагается использовать карту размытости изображения, а в качестве меры размытости – статистическую оценку параметра формы распределения Вейбулла. Параметр формы оценивается в каждой точке изображения по совокупности магнитуд градиента изображения в окрестности точки, при этом применяется разработанная ранее методика построения карты размытости. Эффективность предложенных подходов иллюстрируется конкретными примерами

Pitfall of the Detection Rate Optimized Bit Allocation within template protection and a remedy

One of the requirements of a biometric template protection system is that the protected template ideally should not leak any information about the biometric sample or its derivatives. In the literature, several proposed template protection techniques are based on binary vectors. Hence, they require the extraction of a binary representation from the real- valued biometric sample. In this work we focus on the Detection Rate Optimized Bit Allocation (DROBA) quantization scheme that extracts multiple bits per feature component while maximizing the overall detection rate. The allocation strategy has to be stored as auxiliary data for reuse in the verification phase and is considered as public. This implies that the auxiliary data should not leak any information about the extracted binary representation. Experiments in our work show that the original DROBA algorithm, as known in the literature, creates auxiliary data that leaks a significant amount of information. We show how an adversary is able to exploit this information and significantly increase its success rate on obtaining a false accept. Fortunately, the information leakage can be mitigated by restricting the allocation freedom of the DROBA algorithm. We propose a method based on population statistics and empirically illustrate its effectiveness. All the experiments are based on the MCYT fingerprint database using two different texture based feature extraction algorithms

Video dizilerinden çoğul biyometrik kimlik doğrulama = combining face and voice modalities for person verification from video sequences

In this paper, a multimodal person verification system is presented. The system is based on face and voice modalities. Fusion of information derived from each modality is performed at the matching swre level using sum rule. For face verification statistical subspace tools are utilized as feature exhactors. For speaker verification, me1 frequency cepstral coefficients are used as features and gaussian mixture models are used for modeling. Various wmbination cases are hied in the experiments and the results show that for each case the wmbined modalities performs betfer than the single modality