Graeme Earl

Principles and Practices of Robust, Photography-based Digital Imaging Techniques for Museums

This full day tutorial will use lectures and demonstrations from leading researchers and museum practitioners to present the principles and practices for robust photography-based digital techniques in museum contexts. The tutorial will present many examples of existing and cutting-edge uses of photography-based imaging including Reflectance Transformation Imaging (RTI), Algorithmic Rendering (AR), camera calibration, and methods of imaged-based generation of textured 3D geometry. The tutorial will also explore a framework for Leading museums are now adopting the more mature members of this family of robust digital imaging practices. These practices are part of the emerging science known as Computational Photography (CP). The imaging family’s common feature is the purpose-driven selective extraction of information from sequences of standard digital photographs. The information is extracted from the photographic sequences by computer algorithms. The extracted information is then integrated into a new digital representations containing knowledge not present in the original photogs, examined either alone or sequentially. The tutorial will examine strategies that promote widespread museum adoption of empirical acquisition technologies, generate scientifically reliable digital representations that are ‘born archival’, assist this knowledge’s long-term digital preservation, enable its future reuse for novel purposes, aid the physical conservation of the digitally represented museum materials, and enable public access and research.

New applications of photogrammetry and reflectance transformation imaging to an Easter Island statue

New methods of visualisation offer the potential for a more detailed record of archaeological objects and the ability to create virtual 3D models that can be made widely available online. Here, two different techniques are applied to the impressive Easter Island statue on display in the Wellcome Gallery at the British Museum. Of particular importance are the details revealed of the petroglyphs that decorate its surface.

Virtual relighting of a Roman statue head from Herculaneum: a case study

High-fidelity computer graphics offer the possibility for archaeologists to put excavated cultural heritage artefacts virtually back into their original setting and illumination conditions. This enables hypotheses about the perception of objects and their environments to be investigated in a safe and controlled manner. This paper presents a case study of the pipeline for the acquisition, modelling, rapid prototyping and virtual relighting of a Roman statue head preserved at Herculaneum in Italy. The statue head was excavated in 2006, after having been buried during the eruption of Mount Vesuvius in AD79.

Modeling in Archaeology: Computer Graphic and other Digital Pasts

This paper examines computer graphic simulations of archaeological environments and materials, and explores their formal and informal uses as a means to model archaeological data and archaeological thinking. The papers main contribution is its focus on the perspective of the model-maker rather than upon the consumer, through an understanding of models both as “constructions of past lifeways” and as “‘thinking spaces.” These concepts are explored through two case studies. The first employs models as modes for re-engaging with archaeological material, where the perception of modeled past environments is taken analogically to inform an understanding of the past as imagined. Questions such as the relationship between digital model experience and a former, unattainable past reality are introduced, alongside the potentials and dangers of a model that may become perceptually indistinguishable from reality. In the second case study, models provide new forms of space within which to build interpretations: they are active vessels for interpretation and debate in the present. The case study considers the relationship between presence and the development of interpretation, and considers the agency of digital objects and the possibilities of virtual collaboration. Model building is explored biographically and the paper concludes by placing archaeological graphical models in the broader context of visualization and as tools for interpretation rather than static outputs or modes of dissemination.

Complex networks in archaeology: urban connectivity in iron age and Roman southern Spain

In this article the authors highlight some of the issues surrounding the study of past urban connectivity and how archaeologists can deal with them by adopting a complex networks research perspective.

Visitor Movement and Tracking Techniques. A Visitor-Sourced Methodology for the Interpretation of Archaeological Sites

This paper describes on-going research investigating movement and behaviour patterns of visitors in archaeological sites as a way of informing interpretive planning. A critical point of this study was the development of a hybrid methodology for collecting and assessing data on visitor movement around archaeological sites and of the things that visitors value the most during their visit. This paper demonstrates the methodology developed mainly at Gournia, a Minoan archaeological site of eastern Crete in Greece. Apart from recognised forms of observation and the collection of qualitative data, technologies such as Geographical Positioning System body tracking, geo-tagging and applications of Geographical Information Systems were employed. The interpretation of the processed data provided a better insight and an overview of the sites affordances for movement and as well as the weaknesses of the current interpretation infrastructure. Additionally, the methodology extends to a visitor-sourced approach to reve...

Enhancing research publications using Rich Interactive Narratives

It is desirable in many disciplines to include supplementary information to add value to research publications, particularly in digital form. The concept of interactive publications, in which the reader can browse and navigate through in a nonlinear manner, is one such medium that is explored in this paper. We describe the application of the Rich Interactive Narrative framework to provide such a mechanism in the fields of archaeology and chemistry, to supplement academic journal papers. This system provides both passive (pre-recorded) and active (user-led) interaction modes to navigate through data, including experimental datasets, maps, photos, video and three-dimensional models, and supports event-based audio and text narration. It includes an extensive authoring tool for deployment to the Web. We conclude by discussing the future possibilities of such a platform for e-science and scholarly communication.

Interim report on an enigmatic new Trajanic building at Portus

Excavations by the Portus Project (fig. 1) between the spring and autumn of 2011 uncovered the remains of a major building of uncertain function, possibly associated with ship repairs. Building 5 forms part of a complex of important structures1 situated on the isthmus of land between the great Claudian and Trajanic Basins at the heart of the port (fig. 2). It was a single building of Trajanic date, 247 m long and 58 m wide, which extended from the E facade of the Palazzo Imperiale, which it directly abutted, as far as the corner of the hexagonal Trajanic Basin. Neighbouring buildings included the much smaller Building 72 directly to the east, and the Horrea-Terme3 on the S end of the Monte Giulio (fig. 3).

Underwater reflectance transformation imaging: a technology for in situ underwater cultural heritage object -level recording

There is an increasing demand for high-resolution recording of in situ underwater cultural heritage. Reflectance transformation imaging (RTI) has a proven track record in terrestrial contexts for acquiring high-resolution diagnostic data at small scales. The research presented here documents the first adaptation of RTI protocols to the subaquatic environment, with a scuba-deployable method designed around affordable off-the-shelf technologies. Underwater RTI (URTI) was used to capture detail from historic shipwrecks in both the Solent and the western Mediterranean. Results show that URTI can capture submillimeter levels of qualitative diagnostic detail from in situ archaeological material. In addition, this paper presents the results of experiments to explore the impact of turbidity on URTI. For this purpose, a prototype fixed-lighting semisubmersible RTI photography dome was constructed to allow collection of data under controlled conditions. The signal-to-noise data generated reveals that the RGB channels of underwater digital images captured in progressive turbidity degraded faster than URTI object geometry calculated from them. URTI is shown to be capable of providing analytically useful object-level detail in conditions that would render ordinary underwater photography of limited use.

The xeros data model: tracking interpretations of archaeological finds

At an archaeological dig, interpretations are built around discovered artifacts based on measurements and informed intuition. These interpretations are semi-structured and organic, yet existing tools do not capture their creation or evolution. Patina of Notes (PoN) is an application designed to tackle this, and is underpinned by the Xeros data model. Xeros is a graph structure and a set of operations that can deal with the addition, edition, and removal of interpretations. This data model is a specialisation of the W3C PROV provenance data model, tracking the evolution of interpretations. The model is presented, with operations defined formally, and characteristics of the representation that are beneficial to implementations are discussed.