Automatic Systems for Digitizing Historical Maps

This work is part of a research branch that studies how to acquire metric, semantic and symbolic information from historical maps without damaging the physical support. The technological growth regarding both mechanical instruments and digital high-resolution sensors allowed the development of suitable tools for the digitization of historical maps and creation of more accurate digital models; therefore, by now, the use of automatic systems for acquisition of digital data is continuously spreading. In the work described in this paper we used a robotic arm (UR10), on which we mounted a digital camera in order to acquire high-resolution images of any object following a regular grid. The arm movement was programmed to keep the rotation angles of the camera constant while shifting it at pre-defined quantities along the two axes. The tests performed demonstrated that we could obtain a three-dimensional model with an accuracy below the millimetre in an almost automatic way

Digitizing to Re-discover: the case study of the Roman City-Gate in Altinum, Italy

Graphic documentation in archaeology has always been a primary tool for scholars, used to record, publish and compare data. The vast majority of it, however, is still bi-dimensional, i.e. plans and sections, mostly because it was produced in the last century. Nowadays, sophisticated recording techniques are diffused and regularly utilized by researchers, and they have proven to be relevant to better record and understand an archaeological context. The case-study of the Roman citygate in Altinum is exemplary in this regard: a site that has been dug between 1972 and 1994 and has been exposed to the public since. Recently, a research project, carried out by Ca’ Foscari and Iuav Universities, aims to further re-think and investigate the architectural and urbanistic aspects of the Roman city using digital tools. Because of this, it was possible to conduct a 3D survey of the archaeological areas, including the one where the city-gate is located, and to ensure the preservation of the data in the future. Preliminary elaborations, aimed at comparing the legacy data available on this site with the point clouds from the digitization campaign, show the potential of these tools, even more when studying contexts that are already known and published

An application of integrated 3D technologies for replicas in cultural heritage

In recent decades, 3D acquisition by laser scanning or digital photogrammetry has become one of the standard methods of documenting cultural heritage, because it permits one to analyze the shape, geometry, and location of any artefact without necessarily coming into contact with it. The recording of three-dimensional metrical data of an asset allows one to preserve and monitor, but also to understand and explain the history and cultural heritage shared. In essence, it constitutes a digital archive of the state of an artefact, which can be used for various purposes, be remodeled, or kept safely stored. With the introduction of 3D printing, digital data can once again take on material form and become physical objects from the corresponding mathematical models in a relatively short time and often at low cost. This possibility has led to a different consideration of the concept of virtual data, no longer necessarily linked to simple visual fruition. The importance of creating high-resolution physical copies has been reassessed in light of different types of events that increasingly threaten the protection of cultural heritage. The aim of this research is to analyze the critical issues in the production process of the replicas, focusing on potential problems in data acquisition and processing and on the accuracy of the resulting 3D printing. The metric precision of the printed model with 3D technology are fundamental for everything concerning geomatics and must be related to the same characteristics of the digital model obtained through the survey analysi

From Point Cloud To Video Projection Mapping: Knowing Modern Architecture By Using Light Projection

The ClusterLab HeModern of the Università Iuav di Venezia has been working in recent years on the study, knowledge and conservation of 20th century architecture. This interdisciplinary research group (History of Architecture, Geomatics, Building Technology, Restoration Project) intends to investigate how to analyse and evaluate the state of conservation of the materials of which the modern architectural cultural heritage is composed by identifying specific application protocols for intervention, preservation and valorisation. In 2018, the collaboration between the above-mentioned ClusterLab, the LéaV of the Ecole nationale supérieure d'architecture in Versailles and the Archivio del Moderno of the Accademia di architettura in Mendrisio - Università della Svizzera italiana, culminated in the identification of the works and career of André Bloc as a case study. In the context of this study, the Tour, the Engineer's posthumous work, was selected to serve as a sample for research on the methods of communication of the contents of the architecture, the survey procedures used and the elaborations obtained. So, after the survey campaign, which took place via topographic, laser scanning and photogrammetric methods, two different levels of restitution were conceived: the first, made according to the canonical graphic paper methods, represents the procedural and surveying information, the material characterisation and the state of decay; the second elevates the same contents by applying them to physical reality. In this phase, the research focused on the possibility of making the different projects collaborate through the technique of rapid prototyping and video projection mapping. This particular form of augmented reality was used to enrich, through the mediation of light projections, the sensory perception of the observers by adding more information and emphasising those of greatest interest, proposing an alternative way of storytelling. In fact, unlike other forms of augmented reality, in the case of video projection mapping, the observer has the possibility to interact continuously with the physical reality, whose character is static, while the transmission of data is dynamic and can range in heterogeneity. The elaborations produced were presented in form of a museum exhibit at the international conference "Arti e architettura. Il contributo di André Bloc 1950-1970", which took place in the exhibition rooms of the Università Iuav di Venezia

3d technologies for the digital documentation of an ancient wooden structure

In this paper we would like to present an operational procedure for surveys of complex structures, such as the wooden dome of SS. Giovanni e Paolo in Venice. The aim of this work was to analyse the shape and the geometry of this very articulated constructive technique: because of its complexity, a laser scanning survey, with the support of more traditional methods, such as direct and topographic survey, seemed to be the best way to analyse this structure: from the data elaboration it was possible to create a 3D model of each element as in reality, without any simplification. In line with the growing demand of digital documentation in the field of Cultural Heritage, the 3D technology applied to this research allowed an immediate reading of the whole architectural system. This paper analyses the difficulties encountered during the survey and illustrates the solutions chosen to overcome them

THE VENETIAN GALEA: From the WOODEN MODEL to the DIGITAL MODEL

The Venetian galea (galley), dominating the Mediterranean Sea for almost 1000 years, is one of the most emblematic and fascinating objects in the history and culture of the Serenissima Republic of San Marco, the official name of ancient Venice. This boat has changed according to the needs and developments that have taken place over the centuries, proving versatile and powerful in military and commercial use. Unfortunately, no complete specimen has been received, and everything that can be known about galleys derives from paintings made in different eras, in models and in some original parts, kept inside the Naval Historical Museum of Venice. Another source are some manuscripts, where part of the traditional shipbuilding knowledge is handed down. To understand a galley it is necessary to understand which techniques were used by the proti (directors of the ancient shipyard) which differ substantially from the current design. These techniques were the synthesis of knowledge handed down from person to person and which did not make use of design drawings such as are used today. To obtain the reconstruction of a galley, lacking complete original drawings, we collected and analyzed different documentation that testified the ancient forms. The presented work aims to reconstruct a digital model of a galea starting from the photogrammetric and laser scanning survey of a wooden model of the hull of half of a 25-bench galley of the mid-seventeenth century. The surveyed maquette and brought back to the real scale was integrated by some artifacts present at the Naval History Museum of Venice, surveyed with photogrammetric techniques and laser scanning too. In this way a hypothetical configuration was reconstructed (by synthesis of collected and historical data) which shows the shape that this boat could reasonably have had. The result is a digital model, then printed to the scale, obtained by three-dimensional modeling starting from the point clouds of the maquette and the original artifacts. This final model has been compared with all the iconographic and documentary sources for its historical validation. The results obtained were used for a set-up aimed at enhancing the museum, because it was intended for a large audienc

3D Digitization and Web Publishing of an ISMAR Cartographic Heritage: Historical Maps of Venice Lagoon

Recently a collection of ancient maps was found in the Institute of Marine Sciences of CNR in Venice. The collection includes maps, perspective views, pilot books and ancient manuscripts: this work took into account a selection of maps and documents representing the Venice Lagoon and the Adriatic coast. The first part of this research focused on the application of a scientific method for digital acquisition of historical cartography; thanks to the Geomatic tools and especially to digital photogrammetry it is possible to acquire metric, semantic and symbolic information and also the three-dimensional shape of the geometrical support to correct the deformations occurred over time. In order to allow historical and morphological analysis of the Venice Lagoon, one of the main goals of this research will be the creation of a digital catalogue on a web-gis platform with all the ancient maps acquired. In this way it will be possible to query and to overlap the maps in an interactive way, allowing studies and comparisons with the more recent cartography. The applied procedure of recovery and valorization of historical cartography is divided into three different phases: acquisition, georeferencing and data elaboration of maps in a digital environment. This research underlines the application of a scientific procedure for the conservation and valorization of the historical Cartographic Heritage

New Tools for Urban Analysis: A SLAM-Based Research in Venice

This research proposes a detailed analysis of the potential of MMS (Mobile Mapping Systems), supported by SLAM (Simultaneous Localisation And Mapping) algorithms, performed on a multiscale test field in order to make a concrete contribution to the morphological study of cities. These systems, developed with the aim of acquiring a large number of points in a short time, are able to map the surrounding area and automatically localise themselves in real time in relation to a determined reference system. The analysed area, located in Venice, was divided into three different test fields characterised by typical elements potentially comparable to those of other urban realities. The data were acquired using the LiBackPack C50, Kaarta Stencil and Heron Lite systems and compared quantitatively and qualitatively with data obtained from more traditional surveying techniques. Specifically, the data obtained from TLS (Terrestrial Laser Scanning) surveys, supported by topographic measurements, were the most accurate basis on which to evaluate the accuracy and completeness of the three different MMS devices. The standard deviation values were initially analysed in the final 3D global models using the C2C (Cloud to Cloud) and C2M (Cloud to Mesh) distance calculation methods. Subsequently, the geometric differences were investigated through the extraction of horizontal profiles, and two more specific 2D analyses were carried out: the first inspecting the residual parameters calculated after the Helmert transformation from two sets of control points obtained from the profiles, followed by a local strain analysis. The study of the local deformation parameters allowed us to validate the results obtained and to identify the real limits of these survey instruments. The aim was to make a concrete contribution to the formalisation of an operative protocol for the morphological study of the city, exploiting the potential of these technologies to overcome the differences in scale and the gap between outdoor and indoor spaces

The bust o Francesco II Gonzaga: from digital documentation to 3d printing

Geomatics technics and methods are now able to provide a great contribution to the Cultural Heritage (CH) processes, being adaptable to different purposes: management, diagnosis, restoration, protection, study and research, communication, formation and fruition of the Cultural Heritage. This experimentation was done with an eye to encouraging and promoting the development of principles and good practices for recording, documentation and information management of cultural heritage This research focuses on the documentation path of a cultural asset, in particular a Renaissance statue, aimed to achieve a three dimensional model useful for many digital applications and for solid reproduction. The digital copy can be used in many contexts and represents an efficient tool to preserve and promote CH. It can be included in virtual museum archives and catalogues, shared on network with cultural operators and users, and it permits the contextualization of the asset in its artistic and historical background. Moreover, the possibility to obtain a hard copy, reproduced through 3D printing, allows to reach new opportunities of interaction with CH. In this article, two techniques for the digitization of the terracotta bust of Francesco II Gonzaga, in the City Museum of Mantua, are described: the triangulation scanner and dense image matching photogrammetry. As well as the description of the acquisition and the elaborations, other aspects are taken into account: the characteristics of the object, the place for the acquisition, the ultimate goal and the economic availability. There are also highlighted the optimization pipeline to get the correct three-dimensional models and a 3D printed copy. A separate section discusses the comparison of the realized model to identify the positive and negative aspects of each adopted application

DIGITAL SURVEY TECHNIQUES FOR THE DOCUMENTATION OF WOODEN SHIPWRECKS

Nowadays, researchers widely employ the acquisition of point clouds as one of the principal type of documentation for cultural heritage. In this paper, different digital survey techniques are employed to document a wooden ancient shipwreck, a particular and difficult kind of archaeological finding due to its material characteristics. The instability of wood and the high costs of restoration do not always offer the opportunity of recovering and showing the hull to researchers and public and three-dimensional surveys are fundamental to document the original conditions of the wood. The precarious conditions of this material in contact with air could modify the structure and the size of the boat, requiring a fast and accurate recording technique. The collaboration between Ca' Foscari University and the Laboratory of Photogrammetry of Iuav University of Venice has given the possibility to demonstrate the utility of these technology. We have surveyed a sewn boat of Roman age through multi-image photogrammetry and laser scanner. Point clouds were compared and a residual analysis was done, to verify the characteristics and the opportunity of the two techniques, both of them have allowed obtaining a very precise documentation from a metrical point of view