135 research outputs found
CoNAN: Conditional Neural Aggregation Network For Unconstrained Face Feature Fusion
Face recognition from image sets acquired under unregulated and uncontrolled
settings, such as at large distances, low resolutions, varying viewpoints,
illumination, pose, and atmospheric conditions, is challenging. Face feature
aggregation, which involves aggregating a set of N feature representations
present in a template into a single global representation, plays a pivotal role
in such recognition systems. Existing works in traditional face feature
aggregation either utilize metadata or high-dimensional intermediate feature
representations to estimate feature quality for aggregation. However,
generating high-quality metadata or style information is not feasible for
extremely low-resolution faces captured in long-range and high altitude
settings. To overcome these limitations, we propose a feature distribution
conditioning approach called CoNAN for template aggregation. Specifically, our
method aims to learn a context vector conditioned over the distribution
information of the incoming feature set, which is utilized to weigh the
features based on their estimated informativeness. The proposed method produces
state-of-the-art results on long-range unconstrained face recognition datasets
such as BTS, and DroneSURF, validating the advantages of such an aggregation
strategy.Comment: Paper accepted at IJCB 202
An overview of artificial intelligence and robotics. Volume 1: Artificial intelligence. Part B: Applications
Artificial Intelligence (AI) is an emerging technology that has recently attracted considerable attention. Many applications are now under development. This report, Part B of a three part report on AI, presents overviews of the key application areas: Expert Systems, Computer Vision, Natural Language Processing, Speech Interfaces, and Problem Solving and Planning. The basic approaches to such systems, the state-of-the-art, existing systems and future trends and expectations are covered
Multibiometric security in wireless communication systems
This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University, 05/08/2010.This thesis has aimed to explore an application of Multibiometrics to secured wireless communications. The medium of study for this purpose included Wi-Fi, 3G, and
WiMAX, over which simulations and experimental studies were carried out to assess the performance. In specific, restriction of access to authorized users only is provided by a technique referred to hereafter as multibiometric cryptosystem. In brief, the system is built upon a complete challenge/response methodology in order to obtain a high level of security on the basis of user identification by fingerprint and further confirmation by verification of the user through text-dependent speaker recognition.
First is the enrolment phase by which the database of watermarked fingerprints with
memorable texts along with the voice features, based on the same texts, is created by sending them to the server through wireless channel.
Later is the verification stage at which claimed users, ones who claim are genuine, are verified against the database, and it consists of five steps. Initially faced by the identification level, one is asked to first present oneâs fingerprint and a memorable word, former is watermarked into latter, in order for system to authenticate the fingerprint and verify the validity of it by retrieving the challenge for accepted user.
The following three steps then involve speaker recognition including the user
responding to the challenge by text-dependent voice, server authenticating the response, and finally server accepting/rejecting the user.
In order to implement fingerprint watermarking, i.e. incorporating the memorable word as a watermark message into the fingerprint image, an algorithm of five steps has been developed. The first three novel steps having to do with the fingerprint
image enhancement (CLAHE with 'Clip Limit', standard deviation analysis and
sliding neighborhood) have been followed with further two steps for embedding, and
extracting the watermark into the enhanced fingerprint image utilising Discrete
Wavelet Transform (DWT).
In the speaker recognition stage, the limitations of this technique in wireless
communication have been addressed by sending voice feature (cepstral coefficients)
instead of raw sample. This scheme is to reap the advantages of reducing the
transmission time and dependency of the data on communication channel, together
with no loss of packet. Finally, the obtained results have verified the claims
Multi-Modality Human Action Recognition
Human action recognition is very useful in many applications in various areas, e.g. video surveillance, HCI (Human computer interaction), video retrieval, gaming and security. Recently, human action recognition becomes an active research topic in computer vision and pattern recognition. A number of action recognition approaches have been proposed. However, most of the approaches are designed on the RGB images sequences, where the action data was collected by RGB/intensity camera. Thus the recognition performance is usually related to various occlusion, background, and lighting conditions of the image sequences. If more information can be provided along with the image sequences, more data sources other than the RGB video can be utilized, human actions could be better represented and recognized by the designed computer vision system.;In this dissertation, the multi-modality human action recognition is studied. On one hand, we introduce the study of multi-spectral action recognition, which involves the information from different spectrum beyond visible, e.g. infrared and near infrared. Action recognition in individual spectra is explored and new methods are proposed. Then the cross-spectral action recognition is also investigated and novel approaches are proposed in our work. On the other hand, since the depth imaging technology has made a significant progress recently, where depth information can be captured simultaneously with the RGB videos. The depth-based human action recognition is also investigated. I first propose a method combining different type of depth data to recognize human actions. Then a thorough evaluation is conducted on spatiotemporal interest point (STIP) based features for depth-based action recognition. Finally, I advocate the study of fusing different features for depth-based action analysis. Moreover, human depression recognition is studied by combining facial appearance model as well as facial dynamic model
Advances in Character Recognition
This book presents advances in character recognition, and it consists of 12 chapters that cover wide range of topics on different aspects of character recognition. Hopefully, this book will serve as a reference source for academic research, for professionals working in the character recognition field and for all interested in the subject
Deep Learning for Scene Text Detection, Recognition, and Understanding
Detecting and recognizing texts in images is a long-standing task in computer vision. The goal of this task is to extract textual information from images and videos, such as recognizing license plates. Despite that the great progresses have been made in recent years, it still remains challenging due to the wide range of variations in text appearance. In this thesis, we aim to review the existing issues that hinder current Optical Character Recognition (OCR) development and explore potential solutions. Specifically, we first investigate the phenomenon of unfair comparisons between different OCR algorithms caused due to the lack of a consistent evaluation framework. Such an absence of a unified evaluation protocol leads to inconsistent and unreliable results, making it difficult to compare and improve upon existing methods. To tackle this issue, we design a new evaluation framework from the aspect of datasets, metrics, and models, enabling consistent and fair comparisons between OCR systems. Another issue existing in the field is the imbalanced distribution of training samples. In particular, the sample distribution largely depended on where and how the data was collected, and the resulting data bias may lead to poor performance and low generalizability on under-represented classes. To address this problem, we took the driving license plate recognition task as an example and proposed a text-to-image model that is able to synthesize photo-realistic text samples. By using this model, we synthesized more than one million samples to augment the training dataset, significantly improving the generalization capability of OCR models. Additionally, this thesis also explores the application of text vision question answering, which is a new and emerging research topic among the OCR community. This task challenges the OCR models to understand the relationships between the text and backgrounds and to answer the given questions. In this thesis, we propose to investigate evidence-based text VQA, which involves designing models that can provide reasonable evidence for their predictions, thus improving the generalization ability.Thesis (Ph.D.) -- University of Adelaide, School of Computer and Mathematical Sciences, 202
Multimodal interaction with mobile devices : fusing a broad spectrum of modality combinations
This dissertation presents a multimodal architecture for use in mobile scenarios such as shopping and navigation. It also analyses a wide range of feasible modality input combinations for these contexts. For this purpose, two interlinked demonstrators were designed for stand-alone use on mobile devices. Of particular importance was the design and implementation of a modality fusion module capable of combining input from a range of communication modes like speech, handwriting, and gesture. The implementation is able to account for confidence value biases arising within and between modalities and also provides a method for resolving semantically overlapped input. Tangible interaction with real-world objects and symmetric multimodality are two further themes addressed in this work. The work concludes with the results from two usability field studies that provide insight on user preference and modality intuition for different modality combinations, as well as user acceptance for anthropomorphized objects.Diese Dissertation prĂ€sentiert eine multimodale Architektur zum Gebrauch in mobilen UmstĂ€nden wie z. B. Einkaufen und Navigation. AuĂerdem wird ein groĂes Gebiet von möglichen modalen Eingabekombinationen zu diesen UmstĂ€nden analysiert. Um das in praktischer Weise zu demonstrieren, wurden zwei teilweise gekoppelte VorfĂŒhrungsprogramme zum \u27stand-alone\u27; Gebrauch auf mobilen GerĂ€ten entworfen. Von spezieller Wichtigkeit war der Entwurf und die AusfĂŒhrung eines ModalitĂ€ts-fusion Modul, das die Kombination einer Reihe von Kommunikationsarten wie Sprache, Handschrift und Gesten ermöglicht. Die AusfĂŒhrung erlaubt die VerĂ€nderung von ZuverlĂ€ssigkeitswerten innerhalb einzelner ModalitĂ€ten und auĂerdem ermöglicht eine Methode um die semantisch ĂŒberlappten Eingaben auszuwerten. Wirklichkeitsnaher Dialog mit aktuellen Objekten und symmetrische MultimodalitĂ€t sind zwei weitere Themen die in dieser Arbeit behandelt werden. Die Arbeit schlieĂt mit Resultaten von zwei Feldstudien, die weitere Einsicht erlauben ĂŒber die bevorzugte Art verschiedener ModalitĂ€tskombinationen, sowie auch ĂŒber die Akzeptanz von anthropomorphisierten Objekten
Multimodal interaction with mobile devices : fusing a broad spectrum of modality combinations
This dissertation presents a multimodal architecture for use in mobile scenarios such as shopping and navigation. It also analyses a wide range of feasible modality input combinations for these contexts. For this purpose, two interlinked demonstrators were designed for stand-alone use on mobile devices. Of particular importance was the design and implementation of a modality fusion module capable of combining input from a range of communication modes like speech, handwriting, and gesture. The implementation is able to account for confidence value biases arising within and between modalities and also provides a method for resolving semantically overlapped input. Tangible interaction with real-world objects and symmetric multimodality are two further themes addressed in this work. The work concludes with the results from two usability field studies that provide insight on user preference and modality intuition for different modality combinations, as well as user acceptance for anthropomorphized objects.Diese Dissertation prĂ€sentiert eine multimodale Architektur zum Gebrauch in mobilen UmstĂ€nden wie z. B. Einkaufen und Navigation. AuĂerdem wird ein groĂes Gebiet von möglichen modalen Eingabekombinationen zu diesen UmstĂ€nden analysiert. Um das in praktischer Weise zu demonstrieren, wurden zwei teilweise gekoppelte VorfĂŒhrungsprogramme zum 'stand-alone'; Gebrauch auf mobilen GerĂ€ten entworfen. Von spezieller Wichtigkeit war der Entwurf und die AusfĂŒhrung eines ModalitĂ€ts-fusion Modul, das die Kombination einer Reihe von Kommunikationsarten wie Sprache, Handschrift und Gesten ermöglicht. Die AusfĂŒhrung erlaubt die VerĂ€nderung von ZuverlĂ€ssigkeitswerten innerhalb einzelner ModalitĂ€ten und auĂerdem ermöglicht eine Methode um die semantisch ĂŒberlappten Eingaben auszuwerten. Wirklichkeitsnaher Dialog mit aktuellen Objekten und symmetrische MultimodalitĂ€t sind zwei weitere Themen die in dieser Arbeit behandelt werden. Die Arbeit schlieĂt mit Resultaten von zwei Feldstudien, die weitere Einsicht erlauben ĂŒber die bevorzugte Art verschiedener ModalitĂ€tskombinationen, sowie auch ĂŒber die Akzeptanz von anthropomorphisierten Objekten
Multibiometric security in wireless communication systems
This thesis has aimed to explore an application of Multibiometrics to secured wireless communications. The medium of study for this purpose included Wi-Fi, 3G, and WiMAX, over which simulations and experimental studies were carried out to assess the performance. In specific, restriction of access to authorized users only is provided by a technique referred to hereafter as multibiometric cryptosystem. In brief, the system is built upon a complete challenge/response methodology in order to obtain a high level of security on the basis of user identification by fingerprint and further confirmation by verification of the user through text-dependent speaker recognition. First is the enrolment phase by which the database of watermarked fingerprints with memorable texts along with the voice features, based on the same texts, is created by sending them to the server through wireless channel. Later is the verification stage at which claimed users, ones who claim are genuine, are verified against the database, and it consists of five steps. Initially faced by the identification level, one is asked to first present oneâs fingerprint and a memorable word, former is watermarked into latter, in order for system to authenticate the fingerprint and verify the validity of it by retrieving the challenge for accepted user. The following three steps then involve speaker recognition including the user responding to the challenge by text-dependent voice, server authenticating the response, and finally server accepting/rejecting the user. In order to implement fingerprint watermarking, i.e. incorporating the memorable word as a watermark message into the fingerprint image, an algorithm of five steps has been developed. The first three novel steps having to do with the fingerprint image enhancement (CLAHE with 'Clip Limit', standard deviation analysis and sliding neighborhood) have been followed with further two steps for embedding, and extracting the watermark into the enhanced fingerprint image utilising Discrete Wavelet Transform (DWT). In the speaker recognition stage, the limitations of this technique in wireless communication have been addressed by sending voice feature (cepstral coefficients) instead of raw sample. This scheme is to reap the advantages of reducing the transmission time and dependency of the data on communication channel, together with no loss of packet. Finally, the obtained results have verified the claims.EThOS - Electronic Theses Online ServiceGBUnited Kingdo
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