Davide Tanasi

Augmented Perception of the Past. The Case of Hellenistic Syracuse

The aim of this paper is to present a real-time interaction system for ancient artifacts digitally restored in a virtual environment. Using commercial hardware and open source software, Augmented Reality versions of archaeological artifacts are experienced on mobile devices both in a real outdoor site as well as an indoor museum. The case study for this project is represented by two artifacts of Syracuse, Italy, a statue and an altar, dated back to Hellenistic time. Virtual replicas of the two artifacts were produced applying different techniques. Later the two projects became part of the same research plan aimed to virtually rebuild the most significant artistic and architectural features of Hellenistic Syracuse. Besides the simple production of 3D models, via laserscanning and 3D modelling, a digital process of visual improvement of the statue was preliminary carried out based on photographic documentation of some archetypes. The commercial framework for mobile devices, ARToolworks, has been used for developing Augmented Reality applications. Using a pattern that is recognized by the device, the virtual model is shown as it is in the real world. The novelty of this work is that graduate students in virtual archaeology and non computer programmers such as museum staff, could benefit of this work and implement such a system.

Augmented Perception of the Past: The Case of the Telamon from the Greek Theater of Syracuse

The paper presents a system of real–time interaction with ancient artifacts digitally restored in a virtual environment in which the perception of reality is augmented, through the provision of the visual data missing in the current conditions of the artifacts themselves. The application of this system will be through common mobile devices, like the Apple Iphone. The case study for this project is a Late Classical Greek statue of a Telamon from the Theater of Syracuse. Since the statue is subject to constant degradation, a virtual replica was created through the application of laser scanning techniques. Once the 3D model of the Telamon was produced, a process of digital restoration based on archetypes and photographic documentation of the statue was carried out. Then, the commercial framework for mobile devices, ARToolworks, was used for developing Augmented Reality applications. Using a pattern that is recognized by the device, a three-dimensional model is associated to that pattern and the virtual model is shown as it is in the real world.

Beyond virtual replicas: 3d modeling and maltese prehistoric architecture

In the past decade, computer graphics have become strategic for the development of projects aimed at the interpretation of archaeological evidence and the dissemination of scientific results to the public. Among all the solutions available, the use of 3D models is particularly relevant for the reconstruction of poorly preserved sites and monuments destroyed by natural causes or human actions. These digital replicas are, at the same time, a virtual environment that can be used as a tool for the interpretative hypotheses of archaeologists and as an effective medium for a visual description of the cultural heritage. In this paper, the innovative methodology and aims and outcomes of a virtual reconstruction of the Borg in-Nadur megalithic temple, carried out by Archeomatica Project of the University of Catania, are offered as a case study for a virtual archaeology of prehistoric Malta.

Automatic color detection of archaeological pottery with munsell system

A main issue in the archaeological research is the identification of colored surfaces and soils through the application of Munsell system. This method widely used also in other fields, like geology and anthropology, is based on the subjective matching between the real color and its standardized version on Munsell chart. For preventing many possible errors caused by the subjectivity of the system itself, in this paper an automatic method of color detection on selected regions of digital images of archaeological pottery is presented.

Technological Analysis of Sicilian Prehistoric Pottery Production through Small Angle Neutron Scattering Technique

The Middle Bronze Age in Sicily (15th-13th century BC) represents a crucial moment in the evolution of Prehistoric pottery production. However, the scarcity of specific petrographic and chemical studies has represented until now a serious interpretative handicap for archaeologists. The recent study of an important Middle Bronze Age pottery complex from the site of Grotte di Marineo (Licodia Eubea, Catania), offers the possibility to add new significant data in this field. The analyses, carried out on a group of diagnostic samples represent 13% of the whole complex. This allowed us to obtain a precise characterization that surpassed the misleading identification based on the simple autoptic exam. In this context, this paper highlights the potentiality of the small angle neutron scattering (SANS) technique as a non-invasive analytical tool for the study of technological aspects, in conjunction with other, more usual, methodologies such as scanning electron microscopy (SEM), in order to better investigate production technology of Middle Bronze Age Sicilian pottery.

Virtual Anastylosis of Greek Sculpture as Museum Policy for Public Outreach and Cognitive Accessibility

This paper deals with a virtual anastylosis of a Greek Archaic statue from ancient Sicily and the development of a public outreach protocol for those with visual impairment or cognitive disabilities through the application of three-dimensional (3-D) printing and haptic technology. The case study consists of the marble head from Leontinoi in southeastern Sicily, acquired in the 18th century and later kept in the collection of the Museum of Castello Ursino in Catania, and a marble torso, retrieved in 1904 and since then displayed in the Archaeological Museum of Siracusa. Due to similar stylistic features, the two pieces can be dated to the end of the sixth century BC. Their association has been an open problem, largely debated by scholars, who have based their hypotheses on comparisons between pictures, but the reassembly of the two artifacts was never attempted. As a result the importance of such an artifact, which could be the only intact Archaic statue of a kouros ever found in Greek Sicily, has not fully been grasped by the public. Consequently, the curatorial dissemination of the knowledge related with such artifacts is purely based on photographic material. As a response to this scenario, the two objects have been 3-D scanned and virtually reassembled. The result has been shared digitally with the public via a web platform and, in order to include increased accessibility for the public with physical or cognitive disabilities, copies of the reassembled statue have been 3-D printed and an interactive test with the 3-D model has been carried out with a haptic device.

Mobility of men versus mobility of goods: archaeometric characterization of Middle Bronze Age pottery in Malta and Sicily (15th-13th century BC)

The aim of this paper is to offer the first petrographic and chemical characterization of Middle Bronze Age pottery of Malta (Borġ in-Nadur, half of 15th – early 12th century BC) to discriminate, in the multitude of Borġ in-Nadurvessels found in coeval sites of south-eastern and central-western Sicily, between imports and imitations and to precisely define their provenance.The present research may provide new data in order to shed light on the long standing issue about ‘mobility of men’ and ‘mobility of goods’ between the two insular contexts. A significant amount of Borġ in-Nadurpottery from Malta and Sicily have been sampled and subjected to petrographic exam on thin sections; moreover, chemical analyses of major and trace elements were performed by X-ray fluorescence spectrometry.The research is part of an interdisciplinary project, aimed to create a database of petrographic and chemical data of Borġ in-Nadurtype pottery found in Sicily and in the Maltese archipelago, launched by the University of Catania and Arcadia University in partnership with Heritage Malta and the Superintendence of Cultural Heritage of Malta.

1H NMR, 1H-1H 2D TOCSY and GC-MS analyses for the identification of olive oil on Early Bronze Age pottery from Castelluccio (Noto, Italy)

The development of analytical research in recent decades, at the edge between analytical chemistry and archaeology, provides new methods for the study of organic residues that are usually highly sensitive to natural decay. Using Nuclear Magnetic Resonance (NMR) and Gas Chromatography-Mass Spectrometry (GC-MS), it is now possible to chemically identify a series of natural substances preserved in archaeological environments. This paper presents a protocol to detect natural compounds, such as olive oil, from amorphous organic residues discovered inside the pores of prehistoric pottery from the Early Bronze Age settlement of Castelluccio (Noto, Italy), and dated to the end of the 3rd and the beginning of the 2nd millennium Before the Common Era (BCE).

ARCA (Automatic Recognition of Color for Archaeology): A Desktop Application for Munsell Estimation

Archaeologists are used to employing the Munsell Soil Charts on cultural heritage sites to identify colors of soils and retrieved artifacts. The standard practice of Munsell estimation exploits the Soil Charts by visual means. This procedure is error prone, time consuming and very subjective. To obtain an accurate estimation the process should be repeated multiple times and possibly by other users, since colors might not be perceived uniformly by different people. Hence, a method for objective and automatic Munsell estimation would be a valuable asset to the field of archaeology. In this work we present ARCA: Automatic Recognition of Color for Archaeology, a desktop application for Munsell estimation. The following pipeline for Munsell estimation aimed towards archaeologists has been proposed: image acquisition of specimens, manual sampling of the image in the ARCA desktop application, automatic Munsell estimation of the sampled points and creation of a sampling report. A dataset, called ARCA108, consisting of 22, 848 samples has been gathered, in an unconstrained environment, and evaluated with respect to the Munsell Soil Charts. Experimental results are reported to define the best configuration that should be used in the acquisition phase. Color tolerance values of the proposed framework are also reported.

A Digital Approach for the Study of Roman Signacula From Syracuse, Sicily

In the last decade the epigraphists have grown a new interest in signacula, a class of artifacts for a long time neglected. This has brought numerous contributions devoted to the different regional contexts, along with reflections on methodological questions, not to mention the momentum towards the digitizing of a corpus which counts at least 3,500 pieces, confirming the great potential of these artifacts in providing information related not only to the economy and to the administration of the “res”, both in public and private sphere, but also about the profile of the signacula holders. In this scenario, a specific research question has been inspired by the Sicilian seals about 60 signacula and a dozen impressions left by seals on mortar in burial contexts: it is possible to identify unequivocally a signaculum through its impression? Given for granted that the use of 3D documentation will bring along effective results in terms of improved readability of signacula and seals, the aim of this contribute is to establish a protocol for a semi-automatic matching between 3D models of seals and 3D models of impressions. As part of a preliminary scanning campaign of Late Roman impressions on mortars and metal seals from the catacombs of Syracuse, two bronze metal seals were digitized with a NextEngine 3D triangulation laser scanner and subsequently 3D printed with liquid resin with a Formlabs Form 2 SLA high resolution printer. The casts obtained, were experimentally used to create a set of impressions on mortar using different degrees and angles of pressure, in order to create similar but still different stamps. During the next step, the impressions were 3D scanned and used as ground truth for the outlined semi-automatic procedure of matching with the seals. In MeshLab environment, the 3d models of seals and impressions were manually aligned and then the distance between two sets of 3D points was measured using the filter Hausdorff distance in order to validate a matching. This successful exercise could open the way to the proposal of creating a virtual edition of signacula with 3D models metadata. Furthermore, a research agenda may include the design of a machine learning algorithm for matching of 3D meshes.