15,834 research outputs found

    Circle-based Eye Center Localization (CECL)

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    We propose an improved eye center localization method based on the Hough transform, called Circle-based Eye Center Localization (CECL) that is simple, robust, and achieves accuracy on a par with typically more complex state-of-the-art methods. The CECL method relies on color and shape cues that distinguish the iris from other facial structures. The accuracy of the CECL method is demonstrated through a comparison with 15 state-of-the-art eye center localization methods against five error thresholds, as reported in the literature. The CECL method achieved an accuracy of 80.8% to 99.4% and ranked first for 2 of the 5 thresholds. It is concluded that the CECL method offers an attractive alternative to existing methods for automatic eye center localization.Comment: Published and presented at The 14th IAPR International Conference on Machine Vision Applications, 2015. http://www.mva-org.jp/mva2015

    Engineering data compendium. Human perception and performance. User's guide

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    The concept underlying the Engineering Data Compendium was the product of a research and development program (Integrated Perceptual Information for Designers project) aimed at facilitating the application of basic research findings in human performance to the design and military crew systems. The principal objective was to develop a workable strategy for: (1) identifying and distilling information of potential value to system design from the existing research literature, and (2) presenting this technical information in a way that would aid its accessibility, interpretability, and applicability by systems designers. The present four volumes of the Engineering Data Compendium represent the first implementation of this strategy. This is the first volume, the User's Guide, containing a description of the program and instructions for its use

    Unobtrusive and pervasive video-based eye-gaze tracking

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    Eye-gaze tracking has long been considered a desktop technology that finds its use inside the traditional office setting, where the operating conditions may be controlled. Nonetheless, recent advancements in mobile technology and a growing interest in capturing natural human behaviour have motivated an emerging interest in tracking eye movements within unconstrained real-life conditions, referred to as pervasive eye-gaze tracking. This critical review focuses on emerging passive and unobtrusive video-based eye-gaze tracking methods in recent literature, with the aim to identify different research avenues that are being followed in response to the challenges of pervasive eye-gaze tracking. Different eye-gaze tracking approaches are discussed in order to bring out their strengths and weaknesses, and to identify any limitations, within the context of pervasive eye-gaze tracking, that have yet to be considered by the computer vision community.peer-reviewe

    The Discriminative Generalized Hough Transform for Localization of Highly Variable Objects and its Application for Surveillance Recordings

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    This work is about the localization of arbitrary objects in 2D images in general and the localization of persons in video surveillance recordings in particular. More precisely, it is about localizing specific landmarks. Thereby the possibilities and limitations of localization approaches based on the Generalized Hough Transform (GHT), especially of the Discriminative Generalized Hough Transform (DGHT) will be evaluated. GHT-based approaches determine the number of matching model and feature points and the most likely target point position is given by the highest number of matching model and feature points. Additionally, the DGHT comprises a statistical learning approach to generate optimal DGHT-models achieving good results on medical images. This work will show that the DGHT is not restricted to medical tasks but has issues with large target object variabilities, which are frequent in video surveillance tasks. As all GHT-based approaches also the DGHT only considers the number of matching model-feature-point-combinations, which means that all model points are treated independently. This work will show that model points are not independent of each other and considering them independently will result in high error rates. This drawback is analyzed and a universal solution, which is not only applicable for the DGHT but all GHT-based approaches, is presented. This solution is based on an additional classifier that takes the whole set of matching model-feature-point-combinations into account to estimate a confidence score. On all tested databases, this approach could reduce the error rates drastically by up to 94.9%. Furthermore, this work presents a general approach for combining multiple GHT-models into a deeper model. This can be used to combine the localization results of different object landmarks such as mouth, nose, and eyes. Similar to Convolutional Neural Networks (CNNs) this will split the target object variability into multiple and smaller variabilities. A comparison of GHT-based approaches with CNNs and a description of the advantages, disadvantages, and potential application of both approaches will conclude this work.Diese Arbeit beschäftigt sich im Allgemeinen mit der Lokalisierung von Objekten in 2D Bilddaten und im Speziellen mit der Lokalisierung von Personen in Videoüberwachungsaufnahmen. Genauer gesagt handelt es sich hierbei um die Lokalisierung spezieller Landmarken. Dabei werden die Möglichkeiten und Limiterungen von Lokalisierungsverfahren basierend auf der Generalisierten Hough Transformation (GHT) untersucht, insbesondere die der Diskriminativen Generalisierten Hough Transformation (DGHT). Bei GHT-basierten Ansätze wird die Anzahl an übereinstimmenden Modelpunkten und Merkmalspunkten ermittelt und die wahrscheinlicheste Objekt-Position ergibt sich aus der höchsten Anzahl an übereinstimmenden Model- und Merkmalspunkte. Die DGHT umfasst darüber hinaus noch ein statistisches Lernverfahren, um optimale DGHT-Modele zu erzeugen und erzielte damit auf medizinischen Bilder und Anwendungen sehr gute Erfolge. Wie sich in dieser Arbeit zeigen wird, ist die DGHT nicht auf medizinische Anwendungen beschränkt, hat allerdings Schwierigkeiten große Variabilität der Ziel-Objekte abzudecken, wie sie in Überwachungsszenarien zu erwarten sind. Genau wie alle GHT-basierten Ansätze leidet auch die DGHT unter dem Problem, dass lediglich die Anzahl an übereinstimmenden Model- und Merkmalspunkten ermittelt wird, was bedeutet, dass alle Modelpunkte unabhängig voneinander betrachtet werden. Dass Modelpunkte nicht unabhängig voneinander sind, wird im Laufe dieser Arbeit gezeigt werden, und die unabhängige Betrachtung führt gerade bei sehr variablen Zielobjekten zu einer hohen Fehlerrate. Dieses Problem wird in dieser Arbeit grundlegend untersucht und ein allgemeiner Lösungsansatz vorgestellt, welcher nicht nur für die DGHT sondern grundsätzlich für alle GHT-basierten Verfahren Anwendung finden kann. Die Lösung basiert auf der Integration eines zusätzlichen Klassifikators, welcher die gesamte Menge an übereinstimmenden Model- und Merkmalspunkten betrachtet und anhand dessen ein zusätzliches Konfidenzmaß vergibt. Dadurch konnte auf allen getesteten Datenbanken eine deutliche Reduktion der Fehlerrate erzielt werden von bis zu 94.9%. Darüber hinaus umfasst die Arbeit einen generellen Ansatz zur Kombination mehrere GHT-Model in einem tieferen Model. Dies kann dazu verwendet werden, um die Lokalisierungsergebnisse verschiedener Objekt-Landmarken zu kombinieren, z. B. die von Mund, Nase und Augen. Ähnlich wie auch bei Convolutional Neural Networks (CNNs) ist es damit möglich über mehrere Ebenen unterschiedliche Bereiche zu lokalisieren und somit die Variabilität des Zielobjektes in mehrere, leichter zu handhabenden Variabilitäten aufzuspalten. Abgeschlossen wird die Arbeit durch einen Vergleich von GHT-basierten Ansätzen mit CNNs und einer Beschreibung der Vor- und Nachteile und mögliche Einsatzfelder beider Verfahren

    Biometric Systems

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    Biometric authentication has been widely used for access control and security systems over the past few years. The purpose of this book is to provide the readers with life cycle of different biometric authentication systems from their design and development to qualification and final application. The major systems discussed in this book include fingerprint identification, face recognition, iris segmentation and classification, signature verification and other miscellaneous systems which describe management policies of biometrics, reliability measures, pressure based typing and signature verification, bio-chemical systems and behavioral characteristics. In summary, this book provides the students and the researchers with different approaches to develop biometric authentication systems and at the same time includes state-of-the-art approaches in their design and development. The approaches have been thoroughly tested on standard databases and in real world applications

    Infrared face recognition: a comprehensive review of methodologies and databases

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    Automatic face recognition is an area with immense practical potential which includes a wide range of commercial and law enforcement applications. Hence it is unsurprising that it continues to be one of the most active research areas of computer vision. Even after over three decades of intense research, the state-of-the-art in face recognition continues to improve, benefitting from advances in a range of different research fields such as image processing, pattern recognition, computer graphics, and physiology. Systems based on visible spectrum images, the most researched face recognition modality, have reached a significant level of maturity with some practical success. However, they continue to face challenges in the presence of illumination, pose and expression changes, as well as facial disguises, all of which can significantly decrease recognition accuracy. Amongst various approaches which have been proposed in an attempt to overcome these limitations, the use of infrared (IR) imaging has emerged as a particularly promising research direction. This paper presents a comprehensive and timely review of the literature on this subject. Our key contributions are: (i) a summary of the inherent properties of infrared imaging which makes this modality promising in the context of face recognition, (ii) a systematic review of the most influential approaches, with a focus on emerging common trends as well as key differences between alternative methodologies, (iii) a description of the main databases of infrared facial images available to the researcher, and lastly (iv) a discussion of the most promising avenues for future research.Comment: Pattern Recognition, 2014. arXiv admin note: substantial text overlap with arXiv:1306.160
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