Made available in DSpace on 2014-06-12T15:52:53Z (GMT). No. of bitstreams: 1 license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2009 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Este trabalho propõe uma nova abordagem para classificação de objetos em imagens binárias de duas dimensões usando descritores de curvatura, descritores de momento e uma rede neural artificial. O modelo proposto classifica objetos utilizando uma rede neural supervisionada e, através do uso de uma distribuição de probabilidade, associa um coeficiente de certeza para cada classificação. Foram utilizados os descritores de imagens conhecidos por Momento de Hu e o Curvature Scale Space para prover uma representação invariante às transformações das imagens, enquanto que o modelo neural proposto utiliza a correlação máxima entre as representações dos objetos para efetuar a classificação e uma distribuição de probabilidade para calcular o coeficiente de certeza da classificação de cada imagem. A avaliação da robustez baseou-se na medida da precisão da classificação para imagens rotacionadas, escaladas e com transformações não-lineares que formam um conjunto de imagens padrão, usado pelo grupo MPEG na criação da norma MPEG-7, demonstrando assim a aplicabilidade do método

L'arrivée de la norme MPEG-7 pour les vidéos exige la création de structures de haut niveau représentant leurs contenus. Le travail de cette thèse aborde l'automatisation de la fabrication d'une partie de ces structures. Comme point de départ, nous utilisons des outils de segmentation des objets en mouvement. Nos objectifs sont alors : retrouver des objets similaires dans la vidéo, utiliser les similarités entre plans caméras pour construire des regroupements de plans en scènes. Une fois ces structures construites, il est facile de fournir aux utilisateurs finaux des outils de visualisation de la vidéo permettant des navigations interactives : par exemple sauter au prochain plan ou scène contenant un personnage. La difficulté principale réside dans la grande variabilité des objets observés : changements de points de vues, d'échelles, occultations, etc. La contribution principale de cette thèse est la modélisation de la variabilité des observations par un mélange de densités basée sur la théorie du mélange gaussien. Cette modélisation permet de capturer les différentes apparences intra-plan de l'objet suivi et de réduire considérablement le nombre des descripteurs de bas niveaux à indexer par objet suivi. Autour de cette contribution se greffent des propositions qui peuvent être vues comme des mises en oeuvre de cette première pour différentes applications : mise en correspondance des objets suivis représentés par des mélanges gaussiens, fabrication initiale des catégories de tous les objets présents dans une vidéo par une technique de classification non supervisée, extraction de vues caractéristiques et utilisation de la détection d'objets similaires pour regrouper des plans en scènes.

Aplicações multimídia caracterizam-se por necessitar de grandes recursos computacionais e de rede. Frente a estes requisitos, os modelos de desenvolvimento sempre consideraram arquiteturas altamente especializadas e integradas, resultando em estruturas monolíticas que restringem o reuso, bem como exigem grande esforço para realização de alterações. Este tipo de direcionamento limita e dificulta o desenvolvimento de aplicações multimídia complexas e de larga escala. Existe uma demanda por diretrizes de desenvolvimento que consigam atender escopos cada vez mais amplos, suportando aplicações escaláveis, flexíveis, interoperáveis e de fácil programação. Neste contexto, este trabalho propõe o uso conjunto de Arquiteturas Orientadas a Serviço e os padrões MPEG-7 e MPEG-21. Apresenta-se como estas tecnologias podem facilitar o desenvolvimento de novas aplicações multimídia, diminuindo o custo e o esforço de desenvolvimento, e dando suporte às crescentes e diversificadas demandas por novos tipos de aplicações multimídia. O que deu base para o trabalho foi a busca por uma solução que atendesse a alguns requisitos adicionais verificados ao longo do projeto de uma Plataforma de Gerência de Vídeo. Entre outras coisas, é apresentado como as tecnologias que dão suporte ao desenvolvimento de arquiteturas orientadas a serviço se posicionam frente ao desenvolvimento de aplicações multimídia e, como elas, conjuntamente com os padrões MPEG-7 e MPEG-21 estão sendo utilizadas para melhorar a plataforma citada. É apresentado também um processo para modelagem de aplicações segundo os princípios de orientação a serviço, generalizando a solução apresentada para o desenvolvimento de aplicações multimídia quaisquer. Como resultado, pode-se verificar que, apesar de ainda existirem algumas questões a serem tratadas, as tecnologias apresentadas representam conjuntamente uma ferramenta ampla para o desenvolvimento de aplicações multimídia. / Multimedia applications are characterized for demanding huge network and computing resources. Because these demands, the current development models always were based on highly specialized and integrated architectures. Thus, they present monolithic structures which limits reuse, as well requiring a lot of efforts to perform changes. This approach limits the development of complex and large scale multimedia applications. There are demand for development models for enabling larger scopes application, supporting scalable, flexible and ease programming applications. In this context this work proposes the conjugated use of Service Oriented Architectures and the MPEG-7 and MPEG-21 standards. It presents how these technologies can allow multimedia applications ease development, minimizing coasts and efforts. Besides, it is also showed how they answer for the raising and multiple demands for new multimedia applications types. This work motivation was to create a solution to support some additional requirements verified during the design of a Video Management Platform. Among the diversified issues treated in this work, it is presented how technologies supporting Service Oriented Architectures are positioned regarding multimedia applications development, and how they together MPEG-7 and MPEG-21 standards are being used to improve the Platform. It is also presented an analysis process for applying the principles of Service Orientation in the multimedia applications development. The aim is generalizing the presented solution to be applied in any multimedia application development. As result from the whole work, it can be verified that, although there are some issues to be covered, the technologies presented represent a complete tool for multimedia applications development.

Aplicações multimídia caracterizam-se por necessitar de grandes recursos computacionais e de rede. Frente a estes requisitos, os modelos de desenvolvimento sempre consideraram arquiteturas altamente especializadas e integradas, resultando em estruturas monolíticas que restringem o reuso, bem como exigem grande esforço para realização de alterações. Este tipo de direcionamento limita e dificulta o desenvolvimento de aplicações multimídia complexas e de larga escala. Existe uma demanda por diretrizes de desenvolvimento que consigam atender escopos cada vez mais amplos, suportando aplicações escaláveis, flexíveis, interoperáveis e de fácil programação. Neste contexto, este trabalho propõe o uso conjunto de Arquiteturas Orientadas a Serviço e os padrões MPEG-7 e MPEG-21. Apresenta-se como estas tecnologias podem facilitar o desenvolvimento de novas aplicações multimídia, diminuindo o custo e o esforço de desenvolvimento, e dando suporte às crescentes e diversificadas demandas por novos tipos de aplicações multimídia. O que deu base para o trabalho foi a busca por uma solução que atendesse a alguns requisitos adicionais verificados ao longo do projeto de uma Plataforma de Gerência de Vídeo. Entre outras coisas, é apresentado como as tecnologias que dão suporte ao desenvolvimento de arquiteturas orientadas a serviço se posicionam frente ao desenvolvimento de aplicações multimídia e, como elas, conjuntamente com os padrões MPEG-7 e MPEG-21 estão sendo utilizadas para melhorar a plataforma citada. É apresentado também um processo para modelagem de aplicações segundo os princípios de orientação a serviço, generalizando a solução apresentada para o desenvolvimento de aplicações multimídia quaisquer. Como resultado, pode-se verificar que, apesar de ainda existirem algumas questões a serem tratadas, as tecnologias apresentadas representam conjuntamente uma ferramenta ampla para o desenvolvimento de aplicações multimídia. / Multimedia applications are characterized for demanding huge network and computing resources. Because these demands, the current development models always were based on highly specialized and integrated architectures. Thus, they present monolithic structures which limits reuse, as well requiring a lot of efforts to perform changes. This approach limits the development of complex and large scale multimedia applications. There are demand for development models for enabling larger scopes application, supporting scalable, flexible and ease programming applications. In this context this work proposes the conjugated use of Service Oriented Architectures and the MPEG-7 and MPEG-21 standards. It presents how these technologies can allow multimedia applications ease development, minimizing coasts and efforts. Besides, it is also showed how they answer for the raising and multiple demands for new multimedia applications types. This work motivation was to create a solution to support some additional requirements verified during the design of a Video Management Platform. Among the diversified issues treated in this work, it is presented how technologies supporting Service Oriented Architectures are positioned regarding multimedia applications development, and how they together MPEG-7 and MPEG-21 standards are being used to improve the Platform. It is also presented an analysis process for applying the principles of Service Orientation in the multimedia applications development. The aim is generalizing the presented solution to be applied in any multimedia application development. As result from the whole work, it can be verified that, although there are some issues to be covered, the technologies presented represent a complete tool for multimedia applications development.

La nature temporelle de l'audiovisuel impose de passer par le biais de la description pour enrichir les documents et donc les exploiter. Nous soutenons qu'une représentation de la structure et du contenu des documents est nécessaire. Par structure, nous entendons la structure documentaire c'est-à-dire l'organisation méréologique des éléments qui composent le document, tandis que le contenu est une structure conceptuelle, c'est-à-dire une catégorisation de ces éléments. Après une revue des propositions actuelles de modélisation des documents audiovisuels, issues de l'ingénierie documentaire et de l'ingénierie des connaissances, nous montrons qu'aucun des langages étudiés ne permet de traiter ces deux aspects de manière satisfaisante. Nous proposons alors une architecture générale permettant la représentation formelle de la structure et du contenu des documents audiovisuels, qui engendrera une base de connaissances sur laquelle il est possible d'effectuer des raisonnements. Cette architecture se compose d'une ontologie de l'audiovisuel, dont on traduit une partie dans un langage documentaire pour contrôler la structure logique des documents, et d'une ontologie de domaine pour décrire formellement leur contenu. Nous avons développé l'outil DOE (Differential Ontology Editor), qui implémente la méthodologie de construction d'ontologies utilisée. Nous montrons finalement la pertinence de l'approche à l'aide de deux expérimentations utilisant un corpus de vidéos annoté, illustrant ainsi les types d'inférences possibles.

Content-based retrieval of multimedia data has been still an active research area. The efficient retrieval of video data is proven a difficult task for content-based video retrieval systems. In this thesis study, a Content-Based Video Retrieval (CBVR) system that adapts two different index structures, namely Slim-Tree and BitMatrix, for efficiently retrieving videos based on low-level features such as color, texture, shape and motion is presented. The system represents low-level features of video data with MPEG-7 Descriptors extracted from video shots by using MPEG-7 reference software and stored in a native XML database. The low-level descriptors used in the study are Color Layout (CL), Dominant Color (DC), Edge Histogram (EH), Region Shape (RS) and Motion Activity (MA). Ordered Weighted Averaging (OWA) operator in Slim-Tree and BitMatrix aggregates these features to find final similarity between any two objects. The system supports three different types of queries: exact match queries, k-NN queries and range queries. The experiments included in this study are in terms of index construction, index update, query response time and retrieval efficiency using ANMRR performance metric and precision/recall scores. The experimental results show that using BitMatrix along with Ordered Weighted Averaging method is superior in content-based video retrieval systems.

In this study, an automatic video segmentation and classification system based on audio features has been presented. Video sequences are classified such as videos with &ldquo / speech&rdquo / , &ldquo / music&rdquo / , &ldquo / crowd&rdquo / and &ldquo / silence&rdquo / . The segments that do not belong to these regions are left as &ldquo / unclassified&rdquo / . For the silence segment detection, a simple threshold comparison method has been done on the short time energy feature of the embedded audio sequence. For the &ldquo / speech&rdquo / , &ldquo / music&rdquo / and &ldquo / crowd&rdquo / segment detection a multiclass classification scheme has been applied. For this purpose, three audio feature set have been formed, one of them is purely MPEG-7 audio features, other is the audio features that is used in [31] the last one is the combination of these two feature sets. For choosing the best feature a histogram comparison method has been used. Audio segmentation system was trained and tested with these feature sets. The evaluation results show that the Feature Set 3 that is the combination of other two feature sets gives better performance for the audio classification system. The output of the classification system is an XML file which contains MPEG-7 audio segment descriptors for the video sequence. An application scenario is given by combining the audio segmentation results with visual analysis results for getting audio-visual video segments.

In this thesis, a system, called Ontology-Driven Video Annotation and Retrieval System (OntoVARS) is developed in order to provide a video management system which is used for ontology-driven semantic content annotation and querying. The proposed system is based on MPEG-7 ontology which provides interoperability and common communication platform with other MPEG-7 ontology compatible systems. The Rhizomik MPEG-7 ontology is used as the core ontology and domain specific ontologies are integrated to the core ontology in order to provide ontology-based video content annotation and querying capabilities to the user. The proposed system supports content-based annotation and spatio-temporal data modeling in video databases by using the domain ontology concepts. Moreover, the system enables ontology-driven query formulation and processing according to the domain ontology instances and concepts. In the developed system, ontology-driven concept querying, spatio-temporal querying, region-based and time-based querying capabilities are performed as simple querying types. Besides these simple query types, compound queries are also generated by combining simple queries with &quot / (&quot / , &quot / )&quot / , &quot / AND&quot / and &quot / OR&quot / operators. For all these query types, the system supports both general and video specific query processing. By this means, the user is able to pose queries on all videos in the video databases as well as the details of a specific video of interest.

The thesis presents a system for content based image retrieval and mining. The research presents a design of a scalable solution for efficient retrieval of images from large image databases using image features such as color, shape and texture. A framework for automatic labeling of images and clustering of meta data in database based on the dominant shapes, textures and colors in the image is proposed. The thesis also presents a new image tagging methodology to annotate the dominant image features to the image as meta data. The users of this system can input a query image and select similar image retrieval criteria by selecting a feature type from amongst color, texture or shape. The system retrieves images from the database that match the specified pattern and displays them by relevance. The user can enter a set of keywords or a combination of keywords that form the input text query. Images in the database that match the input text query are fetched and displayed. This ensures content based similar image search even for text based search. An efficient clustering algorithm is shown to improve the image retrieval by an order of magnitude.

As the size of image databases increases in time, the need for content based image indexing and retrieval become important. Image classification is a key to content based image indexing. In this thesis supervised learning with feed forward back propagation artificial neural networks is used for image classification. Low level features derived from the images are used to classify the images to interpret the high level features that yield semantics. Features are derived using detail histogram correlations obtained by Wavelet Transform, directional edge information obtained by Fourier Transform and color histogram correlations. An image database consisting of 357 color images of various sizes is used for training and testing the structure. The database is indexed into seven classes that represent scenery contents which are not mutually exclusive. The ground truth data is formed in a supervised fashion to be used in training the neural network and testing the performance. The performance of the structure is tested using leave one out method and comparing the simulation outputs with the ground truth data. Success, mean square error and the class recall rates are used as the performance measures. The performances of the derived features are compared with the color and texture descriptors of MPEG-7 using the structure designed. The results show that the performance of the method is comparable and better. This method of classification for content based image indexing is a reliable and valid method for content based image indexing and retrieval, especially in scenery image indexing.