Integrative IRT for documentation and interpretation of archaeological structures

The documentation of built heritage involves tangible and intangible features. Several morphological and metric aspects of architectural structures are acquired throughout a massive data capture system, such as the Terrestrial Laser Scanner (TLS) and the Structure from Motion (SfM) technique. They produce models that give information about the skin of architectural organism. Infrared Thermography (IRT) is one of the techniques used to investigate what is beyond the external layer. This technology is particularly significant in the diagnostics and conservation of the built heritage. In archaeology, the integration of data acquired through different sensors improves the analysis and the interpretation of findings that are incomplete or transformed. Starting from a topographic and photogrammetric survey, the procedure here proposed aims to combine the bidimensional IRT data together with the 3D point cloud. This system helps to overcome the Field of View (FoV) of each IRT image and provides a three-dimensional reading of the thermal behaviour of the object. This approach is based on the geometric constraints of the pair of RGB-IR images coming from two different sensors mounted inside a bi-camera commercial device. Knowing the approximate distance between the two sensors, and making the necessary simplifications allowed by the low resolution of the thermal sensor, we projected the colour of the IR images to the RGB point cloud. The procedure was applied is the so-called Nymphaeum of Egeria, an archaeological structure in the Caffarella Park (Rome, Italy), which is currently part of the Appia Antica Regional Park

Close range mini Uavs photogrammetry for architecture survey

The survey of historical façades contains several bottlenecks, mainly related to the geometrical structure, the decorative framework, the presence of natural or artificial obstacles, the environment limitations. Urban context presents additional restrictions, binding by ground acquisition activity and leading to building data loss. The integration of TLS and close-range photogrammetry allows to go over such stuff, not overcoming the shadows effect due to the ground point of view. In the last year the massive use of UAVs in survey activity has permitted to enlarge survey capabilities, reaching a deeper knowledge in the architecture analysis. In the meanwhile, several behaviour rules have been introduced in different countries, regulating the UAVs use in different field, strongly restricting their application in urban areas. Recently very small and light platforms have been presented, which can partially overcome these rules restrictions, opening to very interesting future scenarios. This article presents the application of one of these very small RPAS (less than 300 g), equipped with a low-cost camera, in a close range photogrammetric survey of an historical building façade in Bologna (Italy). The suggested analysis tries to point out the system accuracy and details acquisition capacity. The final aim of the paper is to validate the application of this new platform in an architectonic survey pipeline, widening the future application of close-range photogrammetry in the architecture acquisition process

e-Archeo. A pilot national project to valorize Italian archaeological parks through digital and virtual reality technologies

Commissioned to ALES spa by the Ministry of Culture (MiC), the e-Archeo project was born with the intention of enhancing and promoting knowledge of some Italian archaeological sites with a considerable narrative potential that has not yet been fully expressed. The main principle that guided the choice of the sites and the contents was of illustrating the various cultures and types of settlements present in the Italian territory. Eight sites were chosen, spread across the national territory from north to south, founded by Etruscans, Greeks, Phoenicians, natives and Romans. e-Archeo has developed multimedia, integrated and multi-channel solutions for various uses and types of audiences, adopting both scientific and narrative and emotional languages. Particular attention was paid to multimedia accessibility, technological sustainability and open science. The e-Archeo project was born from a strong synergy between public entities, research bodies and private industries thanks to the collaboration of MiC and ALES with the CNR ISPC, 10 Italian Universities, 12 Creative Industries and the Italian National Television (RAI). This exceptional and unusual condition made it possible to realise all the project’s high-quality contents and several outputs in only one and a half years

Illuminare il segno di Piranesi. La tecnica RTI applicata alle matrici delle Carceri

La raccolta di saggi dedicati alla celebrazione di Giambattista Piranesi nell’occasione del terzo centenario della nascita è stato concepito come un racconto multimediale affidato ad autori italiani e stranieri di diversa formazione disciplinare, specialisti di Piranesi e non, relatori che hanno fatto onore al volume e al suo protagonista, preparando una serie di interventi ricchi di riflessioni oltreché di suggestioni, che sono subito sembrati una importante integrazione ai volumi già pubblicati negli ultimi anni nell'ambito del Progetto Piranesi. Una narrazione complessa che si snoda attraverso "link" richiami e varie “chiavi” che saranno offerte al lettore durante il percorso dei vari capitoli, le immagini, i luoghi, il sonoro. Piranesi multimediale più che un libro è una biblioteca virtuale che concentra più forme comunicative e che consentirà al lettore non solo di conoscere e studiare «le opere del grande incisore», ma anche di approfondire storia e retroscena, creando mappe visuali con avvenimenti, personaggi e idee scoprendo relazioni altrimenti nascoste fra campi del sapere. Il contributo di Ghedin e Menconero, che rientra nel tema dei nuovi metodi per nuovi percorsi di ricerca applicati all’opera di Piranesi, ha come obiettivo quello di ampliare la conoscenza nell’ambito degli studi sulla tecnica incisoria del maestro veneziano. In particolare, si propone la sperimentazione di una nuova modalità di studio del segno inciso, supportata dall’utilizzo della tecnica di reflectance transformation imaging (RTI) che permette di re-illuminare interattivamente l'immagine fotografica delle matrici. Grazie alle possibilità offerte da questa tecnica, dopo l’iniziale acquisizione fotografica a condizione di luce variabile, le superfici incise sono state studiate a monitor, manipolando la luce allo scopo di individuare gli interventi incisori di prima edizione e confrontarli contestualmente con quelli di seconda edizione, riuscendo a vedere, dentro il segno inciso, come i differenti acidi hanno corroso il metallo. Alla tecnica d’incisione indiretta piranesiana, poi, si aggiunge quella condotta direttamente sulle lastre dopo la morsura acida: osservandone la morfologia si è potuto apprezzare al meglio quanto gli studi condotti fin dal 2010 avevano già individuato, ovvero l’uso di strumenti che solcano anche molto profondamente il metallo ma non sono riconducibili all’ortodossia delle tecniche calcografiche

3D Survey in Extreme Environment: The Case Study of LaetoliHominin Footprints in Tanzania

Many cultural assets are in risky situations and they are destined to disappear. Sometimes problems are caused bythe anthropic component (e.g. wars) or by natural disasters (e.g. earthquakes and landslides). At other times thecause of deterioration is due to the slow and inexorable action of atmospheric agents and other natural factorspresent in extreme areas, where preservation of Cultural Heritage is more complex.This contribution deals with 3D documentation of paleontological excavations in extreme contexts that arecharacterized by unfavorable climatic conditions, limited instrumentation and little time available. In particular, thecontribution is focused on the search for a good working procedure which, despite the problems mentioned above,can lead to valid results in terms of accuracy and precision, so that subsequent scientific studies are notcompromised. The proposed case study concerns the recent discovery of fossil footprints at the Site S in Laetoli,within the Ngorongoro Conservation Area (Tanzania), which is a UNESCO World Heritage Site. With the newdiscovery of Site S it was necessary to implement a 3D survey operative protocol with limited equipment and in avery short time. The 3D models, obtained through the “Structure from Motion” (SfM) technique and topographicsupport, were used to perform morphological and morphometric investigations on the new footprints. Through theanalysis it was possible to estimate height and weight of the footprint makers (hominins of the speciesAustralopithecus afarensis). The collected evidence supports marked intraspecific variation in this species, pointingout the occurrence of a considerable difference in size between sexes and suggesting inferences on reproductivebehavior and social structure of these ancient bipedal hominins.The contribution shows how important is to obtain good 3D documentation, even in extreme environment, in orderto reach reliable results for scientific analysis

Frozen in the Ashes

Fossil footprints are very useful palaeontological tools. Their features can help to identify their makers and also to infer biological as well as behavioural information. Nearly all the hominin tracks discovered so far are attributed to species of the genus Homo. The only exception is represented by the trackways found in the late 1970s at Laetoli, which are thought to have been made by three Australopithecus afarensis individuals about 3.66 million years ago. We have unearthed and described the footprints of two more individuals at Laetoli, who were moving on the same surface, in the same direction, and probably in the same timespan as the three found in the 1970s, apparently all belonging to a single herd of bipedal hominins walking from south to north. The estimated stature of one of the new individuals (about 1.65 m) exceeds those previously published for Au. afarensis. This evidence supports the existence of marked morphological variation within the species. Considering the bipedal footprints found at Laetoli as a whole, we can hypothesize that the tallest individual may have been the dominant male, the others smaller females and juveniles. Thus, considerable differences may have existed between sexes in these human ancestors, similar to modern gorillas

Distanze illusorie: l'uso della prospettiva aerea nelle Carceri piranesiane/Illusory distances: the use of aerial perspective in Piranesi's Carceri

La prospettiva aerea in ambito pittorico è resa attraverso la diminuzione della saturazione dei colori, del contrasto tra le parti e della nitidezza dei dettagli. Nell’incisione tale effetto esula dalla componente cromatica e la sua resa dipende molto dalle caratteristiche esecutive delle varie tecniche. In generale, i metodi per ottenere dei gradienti tonali nelle tecniche incisorie riguardano la distanza, l’incrocio e lo spessore dei segni. Quest’ultimo può dipendere dall’uso di punte di diverso spessore o, nel caso dell’acquaforte, dal numero di ‘coperture’. Il contributo presenta uno studio sulla prospettiva aerea delle Carceri di Piranesi condotto attraverso la scomposizione delle tavole in piani di profondità. Dallo studio si evince come l’artista veneto abbia fatto uso di questo effetto, che accentua la profondità e che usualmente viene applicato al paesaggio, in ambienti interni per aumentare la monumentalità dell’architettura e illudere l’osservatore di maggiori distanze.In painting, aerial perspective is rendered through a decrease in colour saturation, contrast between parts and sharpness of details. In engraving, this effect goes beyond the chromatic component, and its rendering depends on the various techniques’ execution characteristics. In general, the methods for obtaining tonal gradients in engraving techniques concern the distance, the crossing, and the thickness of the marks. The latter may depend on the use of tips of different thicknesses or, in the case of etching, on the number of multiple “stoppings-out”. The contribution presents a study on the aerial perspective in Piranesi’s Carceri, conducted by breaking down the plates into planes of depth. The study shows how the Venetian artist applied this effect, which accentuates the depth and is usually applied to landscapes, in interior settings to increase the architecture’s monumentality and illude the observer about greater distances

Image processing for knowledge and comparison of Piranesi’s Carceri editions

Piranesi printed the 16 etchings of the Carceri d’invenzione in 1761. This version, which is more widespread and better known, derives from the reworking of matrices that the Venetian engraver produced in 1749–50. These are the 14 plates of the Invenzioni capricciose di Carceri all’acquaforte. Many studies have focused on the semantic and formal comparison of the two main versions of the series. Up to now, comparisons have been conducted using juxtaposed pictures, whether original prints or digital reproductions. This procedure involves some limitations due to the effort of synthesis and mental superimposition of the two pictures of different editions to correctly identify the areas where changes occurred. The contribution proposes a method of formal comparison between the two main editions of the series through the digital superimposition of two states of the same plate so that it is easier, more immediate, and more accurate to note the changes. This method is based on the application of image processing algorithms, which let to obtain a synthesis picture in false colours that clearly shows the modified parts of each plate. Observation of the results has suggested the distinction of two main types of modifications carried out by Piranesi (additions/integrations and removal), clearly identifiable in the synthesis pictures. In addition to its implications for Piranesi studies, this research shows how digital image processing can be an essential tool for knowledge in the field of art

Il santuario e la Casa del Pellegrino di Julio Lafuente a Todi

Il contributo tratta del santuario e della Casa del Pellegrino di Julio Lafuente a Todi

Rilievo, conservazione e valorizzazione delle facciate architettoniche

Il contributo traccia il percorso conoscitivo di quattro facciate architettoniche del borgo di Cantalupo in Sabina: il palazzo Giannini Marini, il palazzo del Governatore, la chiesa di Maria Santissima Assunta in Cielo e il palazzo Ricci Cati. Il rilievo integrato è stato condotto con stazione totale, GNSS, laser scanner e fotogrammetria, e gli elaborati bidimensionali e tridimensionali risultati da tali acquisizioni sono stati usati per lo studio della genesi geometrica delle facciate e per l’analisi del degrado