CHORUS Deliverable 2.1: State of the Art on Multimedia Search Engines

Based on the information provided by European projects and national initiatives related to multimedia search as well as domains experts that participated in the CHORUS Think-thanks and workshops, this document reports on the state of the art related to multimedia content search from, a technical, and socio-economic perspective. The technical perspective includes an up to date view on content based indexing and retrieval technologies, multimedia search in the context of mobile devices and peer-to-peer networks, and an overview of current evaluation and benchmark inititiatives to measure the performance of multimedia search engines. From a socio-economic perspective we inventorize the impact and legal consequences of these technical advances and point out future directions of research

Current Challenges and Visions in Music Recommender Systems Research

Music recommender systems (MRS) have experienced a boom in recent years, thanks to the emergence and success of online streaming services, which nowadays make available almost all music in the world at the user's fingertip. While today's MRS considerably help users to find interesting music in these huge catalogs, MRS research is still facing substantial challenges. In particular when it comes to build, incorporate, and evaluate recommendation strategies that integrate information beyond simple user--item interactions or content-based descriptors, but dig deep into the very essence of listener needs, preferences, and intentions, MRS research becomes a big endeavor and related publications quite sparse. The purpose of this trends and survey article is twofold. We first identify and shed light on what we believe are the most pressing challenges MRS research is facing, from both academic and industry perspectives. We review the state of the art towards solving these challenges and discuss its limitations. Second, we detail possible future directions and visions we contemplate for the further evolution of the field. The article should therefore serve two purposes: giving the interested reader an overview of current challenges in MRS research and providing guidance for young researchers by identifying interesting, yet under-researched, directions in the field

AXMEDIS 2008

The AXMEDIS International Conference series aims to explore all subjects and topics related to cross-media and digital-media content production, processing, management, standards, representation, sharing, protection and rights management, to address the latest developments and future trends of the technologies and their applications, impacts and exploitation. The AXMEDIS events offer venues for exchanging concepts, requirements, prototypes, research ideas, and findings which could contribute to academic research and also benefit business and industrial communities. In the Internet as well as in the digital era, cross-media production and distribution represent key developments and innovations that are fostered by emergent technologies to ensure better value for money while optimising productivity and market coverage

Um arcabouço multimodal para geocodificação de objetos digitais

Orientador: Ricardo da Silva TorresTese (doutorado) - Universidade Estadual de Campinas, Instituto de ComputaçãoResumo: Informação geográfica é usualmente encontrada em objetos digitais (como documentos, imagens e vídeos), sendo de grande interesse utilizá-la na implementação de diferentes serviços. Por exemplo, serviços de navegação baseados em mapas e buscas geográficas podem se beneficiar das localizações geográficas associadas a objetos digitais. A implementação destes serviços, no entanto, demanda o uso de coleções de dados geocodificados. Este trabalho estuda a combinação de conteúdo textual e visual para geocodificar objetos digitais e propõe um arcabouço de agregação de listas para geocodificação multimodal. A informação textual e visual de vídeos e imagens é usada para definir listas ordenadas. Em seguida, elas são combinadas e a nova lista ordenada resultante é usada para definir a localização geográfica de vídeos e imagens. Uma arquitetura que implementa essa proposta foi projetada de modo que módulos específicos para cada modalidade (e.g., textual ou visual) possam ser aperfeiçoados independentemente. Outro componente é o módulo de fusão responsável pela combinação das listas ordenadas definidas por cada modalidade. Outra contribuição deste trabalho é a proposta de uma nova medida de avaliação da efetividade de métodos de geocodificação chamada Weighted Average Score (WAS). Ela é baseada em ponderações de distâncias que permitem avaliar a efetividade de uma abordagem, considerando todos os resultados de geocodificação das amostras de teste. O arcabouço proposto foi validado em dois contextos: desafio Placing Task da iniciativa MediaEval 2012, que consiste em atribuir, automaticamente, coordenadas geográficas a vídeos; e geocodificação de fotos de prédios da Virginia Tech (VT) nos EUA. No contexto do desafio Placing Task, os resultados mostram como nossa abordagem melhora a geocodificação em comparação a métodos que apenas contam com uma modalidade (sejam descritores textuais ou visuais). Nós mostramos ainda que a proposta multimodal produziu resultados comparáveis às melhores submissões que também não usavam informações adicionais além daquelas disponibilizadas na base de treinamento. Em relação à geocodificação das fotos de prédios da VT, os experimentos demostraram que alguns dos descritores visuais locais produziram resultados efetivos. A seleção desses descritores e sua combinação melhoraram esses resultados quando a base de conhecimento tinha as mesmas características da base de testeAbstract: Geographical information is often enclosed in digital objects (like documents, images, and videos) and its use to support the implementation of different services is of great interest. For example, the implementation of map-based browser services and geographic searches may take advantage of geographic locations associated with digital objects. The implementation of such services, however, demands the use of geocoded data collections. This work investigates the combination of textual and visual content to geocode digital objects and proposes a rank aggregation framework for multimodal geocoding. Textual and visual information associated with videos and images are used to define ranked lists. These lists are later combined, and the new resulting ranked list is used to define appropriate locations. An architecture that implements the proposed framework is designed in such a way that specific modules for each modality (e.g., textual and visual) can be developed and evolved independently. Another component is a data fusion module responsible for combining seamlessly the ranked lists defined for each modality. Another contribution of this work is related to the proposal of a new effectiveness evaluation measure named Weighted Average Score (WAS). The proposed measure is based on distance scores that are combined to assess how effective a designed/tested approach is, considering its overall geocoding results for a given test dataset. We validate the proposed framework in two contexts: the MediaEval 2012 Placing Task, whose objective is to automatically assign geographical coordinates to videos; and the task of geocoding photos of buildings from Virginia Tech (VT), USA. In the context of Placing Task, obtained results show how our multimodal approach improves the geocoding results when compared to methods that rely on a single modality (either textual or visual descriptors). We also show that the proposed multimodal approach yields comparable results to the best submissions to the Placing Task in 2012 using no additional information besides the available development/training data. In the context of the task of geocoding VT building photos, performed experiments demonstrate that some of the evaluated local descriptors yield effective results. The descriptor selection criteria and their combination improved the results when the used knowledge base has the same characteristics of the test setDoutoradoCiência da ComputaçãoDoutora em Ciência da Computaçã