That obscure object of desire: multimedia metadata on the Web, part 2

Abstract

C e n t r u m v o o r W i s k u n d e e n I n f o r m a t i c a INformation SystemsThat Obscure Object of Desire: Multimedia Metadata on the Web (Part I) Jacco van Ossenbruggen, Frank Nack, Lynda Hardman ABSTRACT This article discusses the state of the art in metadata for audio-visual media in large semantic networks, such as the Semantic Web. Our discussion is predominantly motivated by the two most widely known approaches towards machine-processable and semantic-based content description, namely the Semantic Web activity of the W3C and ISO's efforts in the direction of complex media content modeling, in particular the Multimedia Content Description Interface (MPEG-7). We explain that the conceptual ideas and technologies discussed in both approaches are essential for the next step in multimedia development. Unfortunately, there are still many practical obstacles that block their widespread use for providing multimedia metadata on the Web. Based on a scenario to explain our vision of a media-aware Semantic Web, we derive in Part I a number of problems regarding the semantic content description of media units. We then discuss the multimedia production chain, in particular emphasizing the role of progressive metadata production. As a result we distill a set of media-based metadata production requirements and show how current media production environments fail to address these. We then introduce those parts of the W3C and ISO standardization works that are relevant to our discussion. In Part II of this article, we analyze their abilities to define structures for describing media semantics, discuss syntactic and semantic problems, ontological problems for media semantics, and the problems of applying the theoretical concepts to real world problems. Part II concludes with implications of the findings for future action with respect to the actions the community should take. REPORT INS-E0308 DECEMBER 3, 2003 INS ACM Computing Classification AbstractThis article discusses the state of the art in metadata for audio-visual media in large semantic networks, such as the Semantic Web. Our discussion is predominantly motivated by the two most widely known approaches towards machine-processable and semantic-based content description, namely the Semantic Web activity of the W3C and ISO's efforts in the direction of complex media content modeling, in particular the Multimedia Content Description Interface (MPEG-7).We explain that the conceptual ideas and technologies discussed in both approaches are essential for the next step in multimedia development. Unfortunately, there are still many practical obstacles that block their widespread use for providing multimedia metadata on the Web.Based on a scenario to explain our vision of a mediaaware Semantic Web, we derive in part I a number of problems regarding the semantic content description of media units. We then discuss the multimedia production chain, in particular emphasizing the role of progressive metadata production. As a result we distill a set of media-based metadata produ...

Semantic Representation of Multimedia Content

“…The translation approach taken follows rigorously the standard specifications, hence, preserving in this way the intended flexibility of usage. This flexibility however comes with the cost of the inherited ambiguities present in MPEG-7 [36,57], resulting in descriptions with multiple possible interpretations and ambiguous meaning [11].…”

“…colour, shape) and semantic descriptions, as well as aspects pertaining to authoring, user preferences, and so forth. Although the development of MPEG-7 has been a great advancement towards the systematic description of multimedia documents, significant deficiencies pertain to the means for and the axiomatisation of semantics representation [36,57]. To a large extent, these deficiencies issue from the use of XML as the underpinning definition language, the flexibility allowed in the structuring of equivalent descriptions, as well as the restricted, and rather rigorous, model provided for the definition of domain specific semantic descriptions.…”

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

“…All the violations discussed here yield perfectly valid documents with respect to the MPEG-7 XML schema but raise inconsistencies with the semantic constraints that express the intended semantics of the standard. 15 http://frameline.tv/ 16 http://vitooki.sourceforge.net/components/muvino/code/index.html 17 http://www.nhk.or.jp/strl/mpf/english/editor.htm 18 The MPEG-7 Specification Repository is a semantic wiki for sharing information relevant for practical work with MPEG-7, e.g. specifications, examples, tools, events, projects, etc.…”

“…However, these additional constraints are only represented with XML Schema [26], and, for most of them, cannot be automatically checked for consistency by XML processing tools. In other words, profiles provide only very limited control over the semantics of the MPEG-7 descriptions [9,17,21]. Because of this lack of formal semantics, the resulting interoperability problems prevent an effective use of MPEG-7 as a language for describing multimedia.…”

Multimedia annotations on the semantic Web

“…(A thorough comparison and list of the open issues in integrating the MPEG-7 and Semantic Web approaches are available elsewhere. 7,8 ) The task force's framework will cover this by studying the way to define mappings between different multimedia annotations that take advantage of the MPEG-7 standard using OWL. Moreover, in the short term, we need to show how RDF-based software can take advantage of popular existing, non-RDF metadata.…”