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Publications

Publications by Hélder Fernandes Castro

2016

Cognition inspired format for the expression of computer vision metadata

Authors
Castro, H; Monteiro, J; Pereira, A; Silva, D; Coelho, G; Carvalho, P;

Publication
MULTIMEDIA TOOLS AND APPLICATIONS

Abstract
Over the last decade noticeable progress has occurred in automated computer interpretation of visual information. Computers running artificial intelligence algorithms are growingly capable of extracting perceptual and semantic information from images, and registering it as metadata. There is also a growing body of manually produced image annotation data. All of this data is of great importance for scientific purposes as well as for commercial applications. Optimizing the usefulness of this, manually or automatically produced, information implies its precise and adequate expression at its different logical levels, making it easily accessible, manipulable and shareable. It also implies the development of associated manipulating tools. However, the expression and manipulation of computer vision results has received less attention than the actual extraction of such results. Hence, it has experienced a smaller advance. Existing metadata tools are poorly structured, in logical terms, as they intermix the declaration of visual detections with that of the observed entities, events and comprising context. This poor structuring renders such tools rigid, limited and cumbersome to use. Moreover, they are unprepared to deal with more advanced situations, such as the coherent expression of the information extracted from, or annotated onto, multi-view video resources. The work here presented comprises the specification of an advanced XML based syntax for the expression and processing of Computer Vision relevant metadata. This proposal takes inspiration from the natural cognition process for the adequate expression of the information, with a particular focus on scenarios of varying numbers of sensory devices, notably, multi-view video.

2015

Semantically connected web resources with MPEG-21

Authors
Castro, H; Andrade, MT; Almeida, F; Tropea, G; Melazzi, NB; Mousas, AS; Kaklamani, DI; Chiariglione, L; Difino, A;

Publication
MULTIMEDIA TOOLS AND APPLICATIONS

Abstract
The Web is rapidly becoming the prime medium for human socialization. The resources that enable that process (social web sites, blogs, media objects, etc.) present growing complexity and, collectively, weave an ever more intricate web of relationships. Current technology for declaring those relationships is predominantly implicit, ambiguous and semantically poor. As a consequence, their automatic assessment is complex and error prone, preventing the satisfaction of users' needs such as effective semantic searches. To address these limitations, whilst enabling the explicit declaration of semantically unambiguous relationships between digital resources, a solution employing structured semantic descriptors and ontologies was conceived, based on MPEG-21. This paper explains the functioning of the devised mechanism, and goes beyond that, into the definition of two novel employment venues for it, at the service of two real-world usage scenarios. These demonstrate the mechanism's added value as a powerful alternative for the semantically aware interconnection of web resources, and highlight the increased QoE that said mechanism enables.

2014

Digital forgetting in information-centric networks-the CONVERGENCE perspective

Authors
Almeida, F; Castro, H; Andrade, MT; Tropea, G; Melazzi, NB; Signorello, S; Mousas, A; Anadiotis, A; Kaklamani, D; Venieris, I; Minelli, S; Difino, A;

Publication
NEW REVIEW OF HYPERMEDIA AND MULTIMEDIA

Abstract
The Web is rapidly becoming the prime medium for human socialization. As it evolves towards an information-centric operation, it records everything and forgets nothing, assuming that every online resource disclosed by people (photos, posts, multimedia files, etc.) is permanently valid and is to be stored forever. However, throughout their lives, people tend to change, both in their habits as well as in their views and opinions. In many situations, as the years go by, information released loses relevance or people may decide they no longer want others to access information they have previously published. The work presented in this paper strives for a new information persistence paradigm, whereby the enforcement of "digital forgetting" is implemented over an information-centric model for the Internet. The defined solution enables the definitive elimination of digital objects, either on-demand or on a pre-scheduled basis, and, hence, their "forgetting." The solution, conceived within the framework of the European project CONVERGENCE, is based on the employment of metadata descriptions about resources, which unambiguously identify their rightful owners. This additional data is efficiently bound to the resource through the use of an extended version of the MPEG-21 Digital Item specification, and its prescriptions are enforced by CONVERGENCE's distributed provisions.

2013

The Versatile Digital Item

Authors
Castro, H; Difino, A; Tropea, G; Blefari Melazzi, N;

Publication
Signals and Communication Technology - Enhancing the Internet with the CONVERGENCE System

Abstract

2013

The Adoption of Rights Expression Language in CONVERGENCE

Authors
Tropea, G; Bianchi, G; Blefari Melazzi, N; Castro, H; Chiariglione, L; Difino, A; Huebner, T; Christos-Anadiotis, A; Mousas, A;

Publication
Signals and Communication Technology - Enhancing the Internet with the CONVERGENCE System

Abstract

2011

Exploring Semantic Relationships Across Internet Resources

Authors
Hélder Fernandes Castro; Maria Teresa Andrade; Fernando Luís Almeida; Giuseppe Tropea; Nicola Mellazi; Leonardo Chiariglione;

Publication
NWeSP 2011 - 7th International Conference on Next Web Services Practices, Salamanca, Spain

Abstract
As the social character of the Web grows stronger, online multimedia resources become more tangled, exhibiting multiple and complex relationships. Often, these relationships are not easily spotted by search engines because they are not explicit. Still, when searching for content, users would certainly appreciate to receive results indicating all resources that are somehow related to their topic of interest without having to explicitly request for it. In spite of this trend, current technology for declaring and describing resources on the Internet as well as their inter-relationships is very much fragmented and the most commonly used standards, such as HTML, do not offer adequate functionality. While the goal of the MPEG-21 standard is to provide an all encompassing, universal and standard way to perform the declaration of digital resources, the work being developed in the IST CONVERGENCE project has shown that this standard, (specifically its part 3, Digital Item Identification), also has a limited ability to specify relationships between digital resources. This document presents a proposed extension to MPEG-21 Digital Item Identification, which enables it to support a uniform, semantically expressive and precise specification of the relationships between MPEG-21 digital items, rendering it a much more effective tool for a ubiquitous representation and interconnection of digital resources.

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