Martin Höffernig

A metadata model and mapping approach for facilitating access to heterogeneous cultural heritage assets

In the last decade, Europe has put a tremendous effort into making cultural, educational and scientific resources publicly available. Based on national or thematic aggregators, initiatives like Europeana nowadays provide a plethora of cultural resources for people worldwide. Although such massive amounts of rich cultural heritage content are available, the potential of its use for educational and scientific purposes still remains largely untapped. Much valuable content is only available in the so-called long tail, i.e. in niche resources such as specifically themed cultural heritage collections, and are difficult to access from the mainstream hubs like major search engines, social networks or online encyclopaedias. The vision of the EEXCESS project is to push high-quality content from the long tail to platforms and devices which are used every day. The realisation of such use cases requires as a basis (and in addition to the functional components) a common metadata representation and tools for mapping between the data sources’ specific data models and this common representation. In this paper, we propose a data model for such a system that combines federated search results from different cultural heritage data sources. We then propose an approach for metadata mapping, with a focus on easy configurability of mappings, which—once properly configured—can then be executed on the fly by an automatic service. We demonstrate the approach using a real-world example.

VAMP: a service for validating MPEG-7 descriptions w.r.t. to formal profile definitions

MPEG-7 can be used to create complex and comprehensive metadata descriptions of multimedia content. Since MPEG-7 is defined in terms of an XML schema, the semantics of its elements has no formal grounding. In addition, certain features can be described in multiple ways. MPEG-7 profiles are subsets of the standard that apply to specific application areas and that aim to reduce this syntactic variability, but they still lack formal semantics. We propose an approach for expressing the semantics explicitly by formalizing the constraints of various profiles using ontologies, logical rules and ad-hoc programming, thus enabling interoperability and automatic use for MPEG-7 based applications. We have implemented VAMP, a full semantic validation service that detects any inconsistencies of the semantic constraints formalized. Another contribution of this paper is an analysis of how MPEG-7 is practically used. We report on experiments about the semantic validity of MPEG-7 descriptions produced by numerous tools and projects and we categorize the most common errors found.

Mapping audiovisual metadata formats using formal semantics

Audiovisual archives hold enormous amounts of valuable content. However, many of these archives are difficult to access, as their holdings are documented using a range of different metadata formats. Being able to exchange metadata is the key to ensuring access to these collections and to establish interoperability among audiovisual collections, between audiovisual collections and other cultural heritage institutions as well as portals such as Europeana. In this work we attempt to model mappings between metadata formats based on a high-level intermediate concept representation in order to avoid hand-crafted one-to-one mappings between metadata formats. In addition, we define mapping templates on data type level, from which the code for mapping instructions between a pair of formats can be derived. The high-level intermediate concept representation is based on the existing meon ontology and the resulting mapping instructions are expressed using XSLT. As a proof of concept, mappings between two metadata formats are formalized and integrated in a web based prototype application.

Unified Access to Media Metadata on the Web

The goal of the World Wide Web Consortium (W3C) Media Annotation Working Group (MAWG) is to promote interoperability between multimedia metadata formats on the Web. Audio-visual data is omnipresent on todays Web, but different interaction interfaces and especially diverse metadata formats prevent unified search, access, and navigation. MAWG has addressed this issue by developing an interlingua ontology and an associated API. This article discusses the rationale and core concepts of the ontology and API for media resources. The specifications developed by MAWG enable interoperable, contextualized, and semantic annotation and search, independent of the source metadata format, that connects multimedia data to the Linked Data Cloud.

Easing the Creation of Mappings between Metadata Formats

Being able to exchange metadata is the key to ensuring access to collections, establishing interoperability among collections, and between different types of cultural heritage institutions, such as across libraries, museums and audiovisual archives. Motivated by two use cases, one for audiovisual archives and one for museums and general archives, we present an approach for automating mapping between different metadata formats. The mapping approach uses an intermediate ontology and formalises the relations to each of the metadata formats supported. An intuitive web-based configuration user interface is provided in order to build and customise mappings. Based on the two use cases, we discuss two ways of applying the mapping approach: as a web service, which can be included in processes of an audiovisual archives preservation system and integrating of the generated mapping instructions into collection management applications for museums and archives. The proposed approach reduces the effort for defining met...

Generic Access to Multimedia Metadata as a Browser Extension

The variety of multimedia streaming platforms on the Web is ever growing, whereas (metadata) interoperability issues remain unsolved. To address this issue, the World Wide Web Consortium (W3C) launched the Media Annotations Working Group. One output of this group is the API for Media Resource, which defines a unified access to media resources on the Web. This paper introduces the demonstration of the reference implementation of this API as a browser plugin together with a concrete web based show case.

A Reference Implementation of the API for Media Resources

Today many media sharing applications such as Flickr or YouTube exist on the Web that use diverse metadata formats to describe media resources. This leads to interoperability issues [1] in search, retrieval and annotation.