Separability versus prototypicality in handwritten word-image retrieval

Hit lists are at the core of retrieval systems. The top ranks are important, especially if user feedback is used to train the system. Analysis of hit lists revealed counter-intuitive instances in the top ranks for good classifiers. In this study, we propose that two functions need to be optimised: (a) in order to reduce a massive set of instances to a likely subset among ten thousand or more classes, separability is required. However, the results need to be intuitive after ranking, reflecting (b) the prototypicality of instances. By optimising these requirements sequentially, the number of distracting images is strongly reduced, followed by nearest-centroid based instance ranking that retains an intuitive (low-edit distance) ranking. We show that in handwritten word-image retrieval, precision improvements of up to 35 percentage points can be achieved, yielding up to 100% top hit precision and 99% top-7 precision in data sets with 84 000 instances, while maintaining high recall performances. The method is conveniently implemented in a massive scale, continuously trainable retrieval engine, Monk. (C) 2013 Elsevier Ltd. All rights reserved

Casual Information Visualization on Exploring Spatiotemporal Data

The goal of this thesis is to study how the diverse data on the Web which are familiar to everyone can be visualized, and with a special consideration on their spatial and temporal information. We introduce novel approaches and visualization techniques dealing with different types of data contents: interactively browsing large amount of tags linking with geospace and time, navigating and locating spatiotemporal photos or videos in collections, and especially, providing visual supports for the exploration of diverse Web contents on arbitrary webpages in terms of augmented Web browsing

Shape-based image retrieval in iconic image databases.

by Chan Yuk Ming.Thesis (M.Phil.)--Chinese University of Hong Kong, 1999.Includes bibliographical references (leaves 117-124).Abstract also in Chinese.Chapter 1 --- Introduction --- p.1Chapter 1.1 --- Content-based Image Retrieval --- p.3Chapter 1.2 --- Designing a Shape-based Image Retrieval System --- p.4Chapter 1.3 --- Information on Trademark --- p.6Chapter 1.3.1 --- What is a Trademark? --- p.6Chapter 1.3.2 --- Search for Conflicting Trademarks --- p.7Chapter 1.3.3 --- Research Scope --- p.8Chapter 1.4 --- Information on Chinese Cursive Script Character --- p.9Chapter 1.5 --- Problem Definition --- p.9Chapter 1.6 --- Contributions --- p.11Chapter 1.7 --- Thesis Organization --- p.13Chapter 2 --- Literature Review --- p.14Chapter 2.1 --- Trademark Retrieval using QBIC Technology --- p.14Chapter 2.2 --- STAR --- p.16Chapter 2.3 --- ARTISAN --- p.17Chapter 2.4 --- Trademark Retrieval using a Visually Salient Feature --- p.18Chapter 2.5 --- Trademark Recognition using Closed Contours --- p.19Chapter 2.6 --- Trademark Retrieval using a Two Stage Hierarchy --- p.19Chapter 2.7 --- Logo Matching using Negative Shape Features --- p.21Chapter 2.8 --- Chapter Summary --- p.22Chapter 3 --- Background on Shape Representation and Matching --- p.24Chapter 3.1 --- Simple Geometric Features --- p.25Chapter 3.1.1 --- Circularity --- p.25Chapter 3.1.2 --- Rectangularity --- p.26Chapter 3.1.3 --- Hole Area Ratio --- p.27Chapter 3.1.4 --- Horizontal Gap Ratio --- p.27Chapter 3.1.5 --- Vertical Gap Ratio --- p.28Chapter 3.1.6 --- Central Moments --- p.28Chapter 3.1.7 --- Major Axis Orientation --- p.29Chapter 3.1.8 --- Eccentricity --- p.30Chapter 3.2 --- Fourier Descriptors --- p.30Chapter 3.3 --- Chain Codes --- p.31Chapter 3.4 --- Seven Invariant Moments --- p.33Chapter 3.5 --- Zernike Moments --- p.35Chapter 3.6 --- Edge Direction Histogram --- p.36Chapter 3.7 --- Curvature Scale Space Representation --- p.37Chapter 3.8 --- Chapter Summary --- p.39Chapter 4 --- Genetic Algorithm for Weight Assignment --- p.42Chapter 4.1 --- Genetic Algorithm (GA) --- p.42Chapter 4.1.1 --- Basic Idea --- p.43Chapter 4.1.2 --- Genetic Operators --- p.44Chapter 4.2 --- Why GA? --- p.45Chapter 4.3 --- Weight Assignment Problem --- p.46Chapter 4.3.1 --- Integration of Image Attributes --- p.46Chapter 4.4 --- Proposed Solution --- p.47Chapter 4.4.1 --- Formalization --- p.47Chapter 4.4.2 --- Proposed Genetic Algorithm --- p.43Chapter 4.5 --- Chapter Summary --- p.49Chapter 5 --- Shape-based Trademark Image Retrieval System --- p.50Chapter 5.1 --- Problems on Existing Methods --- p.50Chapter 5.1.1 --- Edge Direction Histogram --- p.51Chapter 5.1.2 --- Boundary Based Techniques --- p.52Chapter 5.2 --- Proposed Solution --- p.53Chapter 5.2.1 --- Image Preprocessing --- p.53Chapter 5.2.2 --- Automatic Feature Extraction --- p.54Chapter 5.2.3 --- Approximated Boundary --- p.55Chapter 5.2.4 --- Integration of Shape Features and Query Processing --- p.58Chapter 5.3 --- Experimental Results --- p.58Chapter 5.3.1 --- Experiment 1: Weight Assignment using Genetic Algorithm --- p.59Chapter 5.3.2 --- Experiment 2: Speed on Feature Extraction and Retrieval --- p.62Chapter 5.3.3 --- Experiment 3: Evaluation by Precision --- p.63Chapter 5.3.4 --- Experiment 4: Evaluation by Recall for Deformed Images --- p.64Chapter 5.3.5 --- Experiment 5: Evaluation by Recall for Hand Drawn Query Trademarks --- p.66Chapter 5.3.6 --- "Experiment 6: Evaluation by Recall for Rotated, Scaled and Mirrored Images" --- p.66Chapter 5.3.7 --- Experiment 7: Comparison of Different Integration Methods --- p.68Chapter 5.4 --- Chapter Summary --- p.71Chapter 6 --- Shape-based Chinese Cursive Script Character Image Retrieval System --- p.72Chapter 6.1 --- Comparison to Trademark Retrieval Problem --- p.79Chapter 6.1.1 --- Feature Selection --- p.73Chapter 6.1.2 --- Speed of System --- p.73Chapter 6.1.3 --- Variation of Style --- p.73Chapter 6.2 --- Target of the Research --- p.74Chapter 6.3 --- Proposed Solution --- p.75Chapter 6.3.1 --- Image Preprocessing --- p.75Chapter 6.3.2 --- Automatic Feature Extraction --- p.76Chapter 6.3.3 --- Thinned Image and Linearly Normalized Image --- p.76Chapter 6.3.4 --- Edge Directions --- p.77Chapter 6.3.5 --- Integration of Shape Features --- p.78Chapter 6.4 --- Experimental Results --- p.79Chapter 6.4.1 --- Experiment 8: Weight Assignment using Genetic Algorithm --- p.79Chapter 6.4.2 --- Experiment 9: Speed on Feature Extraction and Retrieval --- p.81Chapter 6.4.3 --- Experiment 10: Evaluation by Recall for Deformed Images --- p.82Chapter 6.4.4 --- Experiment 11: Evaluation by Recall for Rotated and Scaled Images --- p.83Chapter 6.4.5 --- Experiment 12: Comparison of Different Integration Methods --- p.85Chapter 6.5 --- Chapter Summary --- p.87Chapter 7 --- Conclusion --- p.88Chapter 7.1 --- Summary --- p.88Chapter 7.2 --- Future Research --- p.89Chapter 7.2.1 --- Limitations --- p.89Chapter 7.2.2 --- Future Directions --- p.90Chapter A --- A Representative Subset of Trademark Images --- p.91Chapter B --- A Representative Subset of Cursive Script Character Images --- p.93Chapter C --- Shape Feature Extraction Toolbox for Matlab V53 --- p.95Chapter C.l --- central .moment --- p.95Chapter C.2 --- centroid --- p.96Chapter C.3 --- cir --- p.96Chapter C.4 --- ess --- p.97Chapter C.5 --- css_match --- p.100Chapter C.6 --- ecc --- p.102Chapter C.7 --- edge一directions --- p.102Chapter C.8 --- fourier-d --- p.105Chapter C.9 --- gen_shape --- p.106Chapter C.10 --- hu7 --- p.108Chapter C.11 --- isclockwise --- p.109Chapter C.12 --- moment --- p.110Chapter C.13 --- normalized-moment --- p.111Chapter C.14 --- orientation --- p.111Chapter C.15 --- resample-pts --- p.112Chapter C.16 --- rectangularity --- p.113Chapter C.17 --- trace-points --- p.114Chapter C.18 --- warp-conv --- p.115Bibliography --- p.11

Efficient Support for Application-Specific Video Adaptation

As video applications become more diverse, video must be adapted in different ways to meet the requirements of different applications when there are insufficient resources. In this dissertation, we address two sorts of requirements that cannot be addressed by existing video adaptation technologies: (i) accommodating large variations in resolution and (ii) collecting video effectively in a multi-hop sensor network. In addition, we also address requirements for implementing video adaptation in a sensor network. Accommodating large variation in resolution is required by the existence of display devices with widely disparate screen sizes. Existing resolution adaptation technologies usually aim at adapting video between two resolutions. We examine the limitations of these technologies that prevent them from supporting a large number of resolutions efficiently. We propose several hybrid schemes and study their performance. Among these hybrid schemes, Bonneville, a framework that combines multiple encodings with limited scalability, can make good trade-offs when organizing compressed video to support a wide range of resolutions. Video collection in a sensor network requires adapting video in a multi-hop storeand- forward network and with multiple video sources. This task cannot be supported effectively by existing adaptation technologies, which are designed for real-time streaming applications from a single source over IP-style end-to-end connections. We propose to adapt video in the network instead of at the network edge. We also propose a framework, Steens, to compose adaptation mechanisms on multiple nodes. We design two signaling protocols in Steens to coordinate multiple nodes. Our simulations show that in-network adaptation can use buffer space on intermediate nodes for adaptation and achieve better video quality than conventional network-edge adaptation. Our simulations also show that explicit collaboration among multiple nodes through signaling can improve video quality, waste less bandwidth, and maintain bandwidth-sharing fairness. The implementation of video adaptation in a sensor network requires system support for programmability, retaskability, and high performance. We propose Cascades, a component-based framework, to provide the required support. A prototype implementation of Steens in this framework shows that the performance overhead is less than 5% compared to a hard-coded C implementation

Computergestützte Inhaltsanalyse von digitalen Videoarchiven

Der Übergang von analogen zu digitalen Videos hat in den letzten Jahren zu großen Veränderungen innerhalb der Filmarchive geführt. Insbesondere durch die Digitalisierung der Filme ergeben sich neue Möglichkeiten für die Archive. Eine Abnutzung oder Alterung der Filmrollen ist ausgeschlossen, so dass die Qualität unverändert erhalten bleibt. Zudem wird ein netzbasierter und somit deutlich einfacherer Zugriff auf die Videos in den Archiven möglich. Zusätzliche Dienste stehen den Archivaren und Anwendern zur Verfügung, die erweiterte Suchmöglichkeiten bereitstellen und die Navigation bei der Wiedergabe erleichtern. Die Suche innerhalb der Videoarchive erfolgt mit Hilfe von Metadaten, die weitere Informationen über die Videos zur Verfügung stellen. Ein großer Teil der Metadaten wird manuell von Archivaren eingegeben, was mit einem großen Zeitaufwand und hohen Kosten verbunden ist. Durch die computergestützte Analyse eines digitalen Videos ist es möglich, den Aufwand bei der Erzeugung von Metadaten für Videoarchive zu reduzieren. Im ersten Teil dieser Dissertation werden neue Verfahren vorgestellt, um wichtige semantische Inhalte der Videos zu erkennen. Insbesondere werden neu entwickelte Algorithmen zur Erkennung von Schnitten, der Analyse der Kamerabewegung, der Segmentierung und Klassifikation von Objekten, der Texterkennung und der Gesichtserkennung vorgestellt. Die automatisch ermittelten semantischen Informationen sind sehr wertvoll, da sie die Arbeit mit digitalen Videoarchiven erleichtern. Die Informationen unterstützen nicht nur die Suche in den Archiven, sondern führen auch zur Entwicklung neuer Anwendungen, die im zweiten Teil der Dissertation vorgestellt werden. Beispielsweise können computergenerierte Zusammenfassungen von Videos erzeugt oder Videos automatisch an die Eigenschaften eines Abspielgerätes angepasst werden. Ein weiterer Schwerpunkt dieser Dissertation liegt in der Analyse historischer Filme. Vier europäische Filmarchive haben eine große Anzahl historischer Videodokumentationen zur Verfügung gestellt, welche Anfang bis Mitte des letzten Jahrhunderts gedreht und in den letzten Jahren digitalisiert wurden. Durch die Lagerung und Abnutzung der Filmrollen über mehrere Jahrzehnte sind viele Videos stark verrauscht und enthalten deutlich sichtbare Bildfehler. Die Bildqualität der historischen Schwarz-Weiß-Filme unterscheidet sich signifikant von der Qualität aktueller Videos, so dass eine verlässliche Analyse mit bestehenden Verfahren häufig nicht möglich ist. Im Rahmen dieser Dissertation werden neue Algorithmen vorgestellt, um eine zuverlässige Erkennung von semantischen Inhalten auch in historischen Videos zu ermöglichen