by Martin Derr and David Arnold
ICTs’ use for Cultural Heritage has been growing very fast as part of the explosion in digital arts and humanities research driven by both public interest in heritage and the opportunity to enhance intellectual enquiry for Arts and Humanities researchers. Societal interest is at many levels from heritage themes in entertainment, including tourism and computer games, to political interest in heritage and its affect on our sense of identity and citizenship. Like education and health, heritage is personal, though influenced by the collective through commonalities in personal experiences.
The field is also maturing intellectually in a similar way to ICT adoption in other fields, progressing through stages of: replicating pre-existing manual processes; increasing inter-disciplinary collaboration and co-development and; co-development of tools which could not have been conceived or developed without the trust and understanding of previous stages. Leading research in digital humanities has reached this stage, which not only leads to novel techniques in arts and humanities but in computer science. Stokes characterizes this type of result as “use-inspired basic research” which he places in Pasteur’s Quadrant in his scheme ([Stokes, 1997] Stokes, Donald, E. (1997) Pasteur’s Quadrant: Basic Science and Technological Innovation, The Brookings Institution, Washington (ISBN 0-8157-8177-6), pp180).
Figure 1: Stokes’ Quadrant Model of Scientific Research (after [Stokes, 1997], p73).
Cultural heritage may be considered as tangible (artefacts, the written word and documentation) or intangible (oral tradition, stories, performance, etc.), but the distinction may be illusory - written documents require interpretation; the significance of an object depends on the individual’s cultural context etc. ICTs are currently most commonly used with the most tangible aspects, but the longer term challenges, both for the humanities and for ICTs, lie with representing and interrogating meaning, which inevitably spans both tangible and intangible.
Increasingly, 3D digital model representations are providing new challenges and opportunities (David Arnold and Guntram Geser, The EPOCH Research Agenda for the Applications of ICTs to Cultural Heritage. Full Report (May 2008) ISBN 978-963-9911-03-1, available on-line at http://www.epoch.eu). Apart from data volume, there are specific challenges concerning: metadata; the semantics of shape; digital provenance; and long-term preservation. Some of these areas are also challenge digital texts, images and videos but become highlighted when working with 3D. Even more challenging is the integration of knowledge across multiple sources and their metadata.
Libraries and Digital Libraries have survived perfectly well without information integration, providing good, homogeneous finding aids for scholars who know which collection to access. However a cultural-historical research space (museum, library or archive) provides access to primary knowledge about objects in very different organizations and archival material. The information in a museum or archive catalogue will not match the subject classification structure in a library context for example. The museum object is more like an illustration or witness of the past, than the raw information in its own right, some of which may be held as curatorial interpretations within the museum catalogue.
Cultural historical research requires knowledge of “possible pasts” –facts, events, material, social and psychological influences and motivations. It comes to life from understanding contexts by pulling together bits and pieces of related facts from disparate resources, which can typically not be classified under subjects in an obvious way. It lives from taking into account all known facts.
With the advent of interconnected sources, researchers are expected to search data from geographically distributed sources. This is impossible to achieve without ICT support and sophisticated search tools. Video, image and 3D resources exacerbate these challenges with the embedded semantics of image and shape that may not be explicitly recorded in the digitized data and metadata, but require content-based analysis to understand the artefact’s “meaning”.
All digitization generates new metadata, but with 3D additional factors are involved. Models are produced by post-processing scanned or image data and models may be produced using a variety of technologies and algorithms. Understanding the data capture methods and modelling operations may influence future humanities research. For example one study might compare the shape of two objects (eg archaeological fragments) to determine whether they have common origins or analyse two models from different dates to determine whether they represent the same object (for stolen artefacts) or have changed (for condition monitoring over time). The complexities of acquiring 3D mean that different approaches are being taken to cater for the objects’ physical properties. Techniques for acquiring building models are very different from those used for jewellery or costumes for instance, which complicate the design of search tools.
3D highlights other metadata challenges which are always there in principle but not often addressed. Digitizing a book may result in replicating the original – including the original pagination, headers and footnotes, and perhaps the hand-written notations of various owners. Where appearance is preserved by scanned images the challenge of relating image and text data remains.
3D involves complex relationships because many artefacts are composed of sub-parts. Even apparently single items – such as statues – may have several pieces. A complete building has many elements with their own interest – for example the decorative style permeated through dispersed and recurring features.
Detecting segmentation and the inter-relation of parts challenges both the digital representation and search operations. The re-use of a sub-part may also complicate the relationships it represents – a jewel remounted, or the re-use of stone from one historic building in a later building, for example.
At a deeper level, shape embodies semantics that are easily recognisable to the human eye but very difficult to analyse automatically. An archaeologist may recognise part of a cup but automated detection from a collection of shards may be unsolved. An expert may tag a shard as “cup” to simplify the search, but automated search involves feature detection. To detect things produced by the same artist, we would have to define the artist’s “stylistic signatures” from features, as opposed to extracting from text metadata tags. New challenges also arise in detecting co-referencing from digital models of shape and (say) texts that describe an artist’s life. Finally, shape may represent conventional meaning for which there is no linguistic equivalent – gesture or analogy for example. There is no agreed vocabulary of shape elements which would underpin the detection of such meanings from surface characteristics, although application such as face recognition and computer games interfaces may be leading the way.
There is a long way to go before the full potential of ICTs for Cultural Heritage is achieved. In the meantime, the articles in this special issue illustrate the range of research in the field and we look forward to seeing future developments which address these big challenges.
The authors’ work which underpins this article has been supported by 3D-COFORM (“Tools and Expertise for 3D Collection Formation” – http://www.3d-coform.eu) – a large scale integrating research project co-funded by the European Community's Seventh Framework Programme (FP7/2007-2013) under grant agreement no. 231809; 2008-2012. The objective is to improve 3D digitization tools and processes to make 3D documentation a practical alternative for tangible cultural heritage. It builds on many of the challenges recorded in the EPOCH Research Agenda for the use of ICTs with tangible cultural heritage.
The EPOCH Research Agenda for the Applications of ICTs to Cultural Heritage:
3D COFORM project: http://www.3d-coform.eu
University of Brighton, UK