Walter Allasia

Creating Rich Metadata in the TV Broadcast Archives Environment: The PrestoSpace Project

This paper describes the part of the European PrestoSpace project dedicated to the study and development of a metadata access and delivery (MAD) system for television broadcast archives. The mission of the MAD system, inside the wider perspective of the PrestoSpace factory, is to generate, validate and deliver to the archive users metadata created through the employment of both automatic and manual information extraction tools. Automatic tools include audiovisual content analysis and semantic analysis of text extracted by automatic speech recognition (ASR). The MAD publication platform provides access and search facilities to the imported and newly produced metadata in a synergic and easy-to-use interface

An Innovative Approach for Indexing and Searching Digital Rights

Our aim is the management of the metadata related to the digital rights in centralized systems or networks with indexing capabilities for both text and similarity searches, providing the basic infrastructure enabling the private use and the commercial exploitation as well. We present an innovative approach that treats the DRM metadata as metric objects, enabling similarity search on IPR attributes between digital items. Moreover we show how the content base similarity search can help both the user to deal with a huge amount of similar items with different licenses and the content providers to detect fake copies or illegal uses.

100 million hours of audiovisual content: digital preservation and access in the PrestoPRIME project

We report preliminary results of PrestoPRIME, an EU FP7 integrated project, including audiovisual (AV) archives, academics and industrial partners, focused on long-term digital preservation of AV media objects and on improving access by integrating media archives with European on-line digital libraries, specifically Europeana. Project outcomes will result in tools and services to ensure the permanence of digital AV content in archives, libraries, museums and other collections, enabling long-term future access in dynamically changing contexts. PrestoPRIME has a special focus on digital preservation in broadcast environments, where very large files of digital video must be preserved at high quality (suitable for future re-use in an AV production environment) in affordable distributed and federated archives. The adoption of standard solutions for digital preservation processes (metadata representation, content storage, digital rights governance, search and access) enables the interoperability of the proposed preservation framework and guidelines. The OAIS model was chosen for the reference architecture, METS is adopted as wrapper for metadata representation, while relevant standards (e.g. from W3C, ISO/IEC and others) are used for content and rights description. Project outcomes will be delivered through a European networked Competence Centre, to gather knowledge and deliver advanced digital preservation advice and services in conjunction with Europeana and other initiatives.

Automatically detecting changes and anomalies in unmanned aerial vehicle images

The use of unmanned aerial vehicles (UAVs) in civil aviation is growing up quickly, enabling new scenarios, especially in environmental monitoring and public surveillance services. So far, Earth observation has been carried out only through satellite images, which are limited in resolution and suffer from important barriers such as cloud occlusion. Microdrone solutions, providing video streaming capabilities, are already available on the marketplace, but they are limited to altitudes of a few hundred feet. In contrast, UAVs equipped with high quality cameras can fly at altitudes of a few thousand feet and can fill the gap between satellite observations and ground sensors. Therefore, new needs for data processing arise, spanning from computer vision algorithms to sensor and mission management. This paper presents a solution for automatically detecting changes in images acquired at different times by patrolling UAVs flying over the same targets (but not necessarily along the same path or at the same altitude). Change detection in multi-temporal images is a prerequisite for land cover inspection, which, in turn, sets up the basis for detecting potentially dangerous or threatening situations.

Governed Content Distribution on DHT Based Networks

Peer-to-peer (P2P) systems are widely used for sharing digital items without structured metadata and in absence of any kind of digital rights management applied to the distributed contents. In this paper we propose the implementation of a prototype application that makes use of a structured P2P system enabling the indexing of complex metadata, used to express digital rights. In this way the media contents are exchanged and played according to the expressed grants. The creation and the consumption of the shared contents can be performed through any MPEG-21 REL compliant software and the application allows indexing and search for both governed and ungoverned contents. The information about the license can be included in the queries and the P2P network can be used to share governed contents (both free and with fee) in a legitimate way. In particular the proposed approach represents a suitable solution for indexing and querying rights complex structures on DHT based networks.

Digital Rights Metadata Management and Retrieval on Structured Overlay Networks

This paper introduces a suitable way for indexing multimedia metadata on a structured peer-to-peer overlay network, with special care to the management of rights metadata expressed by MPEG-21. We have selected a suitable subset of MPEG-21 rights expression language elements to be indexed, in order to map governed contents into a flat space and allow insertion and retrieval of digital contents. Furthermore, we present a distributed application built on a structured overlay network enabling the search of multimedia items using rights related information. Our solution is completely decentralized and can be exploited in any MPEG-21 compliant metadata representation.

Bridging Information Management and Preservation: A Reference Model

The idea of the Preserve-or-Forget (PoF) approach introduced in this book is to follow a forgetful, focused approach to digital preservation, which is inspired by human forgetting and remembering. Its goal is to ease the adoption of preservation technology especially in the personal and organizational context and to ensure that important content is kept safe, useful, and understandable in the long run. For this purpose, it stresses the smooth interaction between information management and preservation management. Leveraging the PoF approach, in this chapter we introduce a reference model, which will be referred to in the following as PoF Reference Model . The model pays special attention to the functionality which bridges between Information Management System (Active System) and Digital Preservation System (DPS) , such as the selection of content for preservation and the transfer of content between the systems. The model aims to encapsulate the core ideas of the PoF approach, which considers Active System and DPS as a joint ecosystem into a re-usable model, and is inspired by the core principles of this approach: synergetic preservation, managed forgetting, and contextualized remembering. The design of the PoF Reference Model was driven by the identification of five required characteristics for such a reference model: it has to be integrative, value-driven, brain-inspired, forgetful, and evolution-aware. The PoF Reference Model consists of a functional part (Functional Model) and of an associated Information Model. The Functional Model is made up of three layers: Core Layer, Remember and Forget Layer, and Evolution Layer. For each layer, we discuss the main functional entities and the representative workflows, also relating them to existing standards and practices in digital preservation. The functionality required to mediate between the Active System and the DPS has been encapsulated into the PoF Middleware, which has been designed and implemented as part of the ForgetIT project. The Information Model describes the preservation entities and their relationships, also discussing the interoperability with existing digital preservation standards.

Semantic Similarity Between Images: A Novel Approach Based on a Complex Network of Free Word Associations

Several measures exist to describe similarities between digital contents, especially for what concerns images. Nevertheless, distances based on low-level visual features embedded in a multidimensional linear space are hardly suitable for capturing semantic similarities and recently novel techniques have been introduced making use of hierarchical knowledge bases. While being successfully exploited in specific contexts, the human perception of similarity cannot be easily encoded in such rigid structures. In this paper we propose to represent a knowledge base of semantic concepts as a complex network whose topology arises from free conceptual associations and is markedly different from a hierarchical structure. Images are anchored to relevant semantic concepts through an annotation process and similarity is computed following the related paths in the complex network. We finally show how this definition of semantic similarity is not necessarily restricted to images, but can be extended to compute distances between different types of sensorial information such as pictures and sounds, modeling the human ability to realize synaesthesias.

A multi-agent approach for autonomous digital preservation

Keeping the content of digital objects accessible is a key challenge for digital archives, especially those with limited resources dedicated to preservation. This paper describes an agent-based model that simulates processes in which a digital object become obsolescent, thus a preservation action, such as the migration to the most appropriate format, is required. Agents monitor and control the local environment and deal with preservation issues individuating obsolescent formats based on global parameters such as their diffusion. They exchange information to find out the most suitable preservation action: suggestions are evaluated and propagated according to their reciprocal level of trust. The level of trust is automatically updated after every interaction through a feedback mechanism based on stigmergy. The paper shows that the framework has a stable behaviour under several use cases. Therefore this approach is suitable for digital archives that may take advantage of a multi-agent system which can either perform an autonomous preservation action or suggest a list of best candidate solutions to the user.

A complex network model of semantic memory impairments

In the last decades, several models have been proposed to describe the functions and the structure of human memory. Many of these agree in representing semantic memory, i.e. the part of memory which contains the general knowledge about the world, as a network. On the other hand, the study of complex networks is a new and emerging field at the intersection of physics, mathematics and computer science which aims at characterizing the topological properties of large networks. The paper proposes a quantitative study of the large-scale properties of semantic memory, modelled as the knowledge base of an automatic concept classifier of images. This approach allows us to probe the topological properties of the network, showing that it exhibits the marks of complexity, and provide us with a suitable mathematical framework to study memory impairments. These alterations are firstly modelled as nodes removals and secondly as links modifications, producing markedly different results.