Image-Based and Range-Based 3D Modelling of archaeological Cultural Heritage: the Telamon of the Temple of Olympian Zeus in Agrigento (ITALY)

The Temple of Olympian Zeus in Agrigento (Italy) was one of the largest temple and at the same time one of the most original of all the Greek architecture. We don\u2019t know exactly how it was because the temple is now almost completely destroyed but it is very well-known for the presence of the Telamons. The Telamons were giant statues (about 8 meters high) probably located outside the temple to fill the interval between the columns. In accordance with the theory most accredited by archaeologists the Telamons were a decorative element and also a support for the structure. However, this hypothesis has never been scientifically proven. One Telamon has been reassembled and is shown at the Archaeological Museum of Agrigento. In 2009 a group of researchers at the University of Palermo has begun a study to test the hypothesis that the Telamons support the weight of the upper part of the temple. The study consists of a 3D survey of the Telamon, to reconstruct a detailed 3D digital model, and of a structural analysis with the Finite Element Method (FEM) to test the possibility that the Telamon could to support the weight of the upper portion of the temple. In this work the authors describe the 3D survey of Telamon carry out with Range-Based Modelling (RBM) and Image-Based Modeling (IBM). The RBM was performed with a TOF laser scanner while the IBM with the ZScan system of Menci Software and Image Master of Topcon. Several tests were conducted to analyze the accuracy of the different 3D models and to evaluate the difference between laser scanning and photogrammetric data. Moreover, an appropriate data reduction to generate a 3D model suitable for FEM analysis was tested

Vision metrology and Structure from Motion for archaeological heritage 3D reconstruction: A Case Study of various Roman mosaics

Vision metrology and computer vision can be successfully used for archaeological heritage 3D reconstruction in very high uncertainty 3D measurement projects. Of those archaeological objects requiring very accurate measurements (<1 mm), ancient mosaics comprise some of the most important. The aim of this paper is to assess the photogrammetric/computer vision approach in a vision metrology context as part of a 3D mosaics survey. In order to evaluate the optimal photogrammetric/computer vision workflow in this work, three different surveys were performed on three mosaics of different sizes and locations. Two of these are stored at the Antonino Salinas Regional Archaeological Museum in Palermo (Italy) and the other is located at the Baglio Anselmi Regional Archaeological Museum in Marsala (Italy). The mosaics survey was undertaken in order to obtain a very detailed 3D model and a full-scale ortho-image (scale 1:1), which would be useful for documentation and restoration processes. The research involved an evaluation of the potential and the related issues of the photogrammetric/computer vision approach for 3D mosaic documentation, particularly regarding the issue of camera calibration

Computer Vision Tools for 3D Modelling in Archaeology

In archaeological Cultural Heritage study 3D modelling has become a very useful process to obtain indispensable data for documentation and visualization. Nowadays the continuous request to achieve photorealistic 3D models has led to testing different techniques and methodologies to speed up both data acquisition and the data processing phase. There are many examples of surveys conducted with the use of range-based and image-based techniques, but, in the last few years, the scientific research has been increasingly moving towards automatic procedures using Computer Vision approach to reduce time during data processing. Computer Vision approach offers a great opportunity for archaeological survey since it can be very easily used by existing Computer Vision interfaces such as 3D web services and open source or low cost software. The aim of this work is to evaluate the performance offered by Computer Vision interfaces for 3D survey of archaeological ruins using some 3D web-service tools and a low cost software like PhotoScan package. Some tests have been performed to analyze the geometric accuracy of 3D models obtained by 3D web-service tools and PhotoScan package through the comparison with a 3D model achieved by laser scanning survey.Dept. of Civil, Environmental, Aerospace and Materials Engineering, University of Palermo, Viale delle Scienze, 90128 Palermo, Ital

Integrating topographic, photogrammetric and laser scanning techniques for a scan-to-bim process

The preservation of historic buildings can often be particularly difficult due to the lack of detailed information about architectural features, construction details, etc.. However, in recent years considerable technological innovation in the field of Architecture, Engineering, and Construction (AEC) has been achieved by the Building Information Modeling (BIM) process. BIM was developed as a methodology used mainly for new construction but, given its considerable potential, this approach can also be successfully used for existing buildings, especially for buildings of historical and architectural value. In this case, it is more properly referred to as Historic - or Heritage - Building Information Modeling (HBIM). In the HBIM process, it is essential to precede the parametric modeling phase of the building with a detailed 3D survey that allows the acquisition of all geometric information. This methodology, called Scan-to-BIM, involves the use of 3D survey techniques for the production of point clouds as a geometric "database"for parametric modeling. The Scan-to-BIM approach can have several issues relating to the complexity of the survey. The work aims to apply the Scan-to-BIM approach to the survey and modeling of a historical and architectural valuable building to test a survey method, based on integrating different techniques (topography, photogrammetry and laser scanning), that improves the data acquisition phase. The "Real Cantina Borbonica"(Cellar of Royal House of Bourbon) in Partinico (Sicily, Italy) was chosen as a case study. The work has allowed achieving the HBIM of the "Real Cantina Borbonica"and testing an approach based exclusively on a topographic constraint to merge in the same reference system all the survey data (laser scanner and photogrammetric point clouds)

A Scan-to-BIM Approach for the Management of Two Arab-Norman Churches in Palermo (Italy)

The paper shows the results of the research activities carried out by the Department of Engineering at the University of Palermo (Italy), which assessed the application of the Heritage Building Information Modelling (HBIM) methodology through a Scan-to-BIM approach to two local churches belonging to the medieval period. This project was motivated by a renewed interest from the city administrators towards the conservation of cultural heritage dating back to the Arab-Norman domination in Sicily since one of the two buildings was included in the UNESCO World Heritage Sites list in 2015. The morpho-typological style of the churches has been acquired by high-detailed 3D surveys, which provided the base for two HBIM models suited to render the peculiarity of these buildings at their best. The BIM environment allowed both the geometrical representation of all the architectural elements and their further enrichment with the integration of non-geometric data and semantic signification through a knowledge-based workflow. This process led to a hierarchical organization of two high-accuracy digital replicas and to the creation of a database containing all of the architectural items typical of the Arab-Norman style, aimed to share the awareness of its conservation and to match all of the Cultural Heritage requirements. In the future, the features in this database can be shared with other specialists as reference objects for further studies on cultural heritage sites in the UNESCO list

Cryptic invasion in Southern Europe: The case of Ferrissia fragilis (Pulmonata: Ancylidae) Mediterranean populations

Four populations of the North American ancylid gastropod Ferrissia fragilis have been found in Southern Italy, thus expanding the known Eurasian distribution range of this invasive gastropod to the Mediterranean area. Both mitochondrial markers used for the molecular identification of the sampled specimens (16S and COI) showed a modest to absent haplotypic diversity in the studied Ferrissia populations from Europe and Asia, and their perfect identity with some of the haplotypes observed in North American F. fragilis populations. In the light of the scarce molecular diversity observed in the whole Palaearctic area and of the growing evidences for the ongoing spreading of the species in Europe, the occurrence of a single invasion event from North America possibly linked with aquarium plant trade followed by a rapid spreading of the species in Eurasia is suggested. The record of F. fragilis in Southern Italy caused some doubts on the presence of autochthonous Ferrissia populations in Europe and on the actual existence of Ferrissia wautieri. A molecular analysis of Ferrissia specimens from the loci typici of F. wautieri (Northern Italy) and F. clessiniana (Egypt) is definitely opportune

UAV survey for the archaeological map of Lilybaeum (Marsala, Italy)

Collecting information and mapping are fundamental aspects of systematic archaeological excavation, documentation and interpretation. The process of recording physical evidence is the first step in the archaeological study with the goal to derive spatial and semantic information from the gathered and available data. Archaeological reports always include 2D maps, sections, data distribution and other spatial data. Indeed, the representation is inseparable from the archaeological practice, but this is undoubtedly a time-consuming activity. Nowadays, archaeologists can take advantages of various recording techniques to produce highly accurate 3D models and ortho-images of archaeological sites. Far from replacing the more traditional techniques, the development of new geomatics techniques tries to answer, in a more efficient way, to the needs of archaeological research. The use of Unmanned Aerial Vehicles (UAVs) has become more popular in archaeological excavations. In particular, UAV systems become a useful, versatile and cost-effective approach to record large archaeological areas in order to measure and completely document them. They are the fastest way to produce high-resolution 3D models of entire sites and allow archaeologists to collect accurate spatial data that can be used for spatial analyses using GIS platform. The paper presents the results of several UAV surveys of the archaeological remains of Lilybaeum, the ancient city of Marsala (Southern Italy), performed in the Archaeological Park of "Lilibeo". The UAV acquisitions were planned and carried out to complete the previous traditional documentation of the site. Very detailed 3D models and high-resolution ortho-images, together with some new field campaigns, have been used for new analysis and documentation of the site and for the realization of the archaeological map of Lilybaeum