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Original hand drawings by Leonardo are astonishing collections of knowledge, superb representations of the artist's way of working, which proves the technical and cultural peak of the Renaissance era. However, due to their delicate and fragile nature, they are hard to manipulate and compulsory to preserve. To overcome this problem we developed, in a 10-year-long research program, a complete workflow to produce a system able to replace, investigate, describe and communicate ancient fine drawings through what Leonardo calls “ the best sense ” (i.e., the view), the so-called ISLe ( InSightLeonardo ). The outcoming visualization app is targeted to a wide audience made of museum visitors and, most importantly, art historians, scholars, conservators, and restorers. This article describes a specific feature of the workflow: the appearance modeling with the aim of an accurate Real-Time Rendering (RTR) visualization. This development is based on the direct observation of five among the most known Leonardo da Vinci's drawings, spanning his entire activity as a draftsman, and it is the result of an accurate analysis of drawing materials used by Leonardo, in which peculiarities of materials are digitally reproduced at the various scales exploiting solutions that favor the accuracy of perceived reproduction instead of the fidelity to the physical model and their ability to be efficiently implemented over a standard GPU-accelerated RTR pipeline. Results of the development are exemplified on five of Leonardo's drawings and multiple evaluations of the results, subjective and objective, are illustrated, aiming to assess potential and critical issues of the application.

Smartphone camera technology has made significant improvements of sensors quality and software camera performance in recent years. Devices as Apple iPhone X and the Samsung Galaxy S9 Plus, allow to reach levels of image resolution, sharpness and color accuracy very close to prosumer SLR cameras, enabling also on-the-fly processing and procedures which were considered impossible to achieve until a few years ago. Starting from these premises, a series of issues and opportunities concerning smartphone application to artifacts documentation will be discussed. In particular, consistency and reliability of both shape and color representation achievable for small-medium artifacts belonging to exhibitions and museum collections. A low-cost, easy-to-use workflow based on low-cost widespread devices will be compared to consolidated digitization pipelines. The contribution focus is based on color accuracy of textured models achievable through smartphones by means of an internally developed application for the achievement of highly reliable developments of raw formats (.DNG) from Apple iPhone X. Color consistency will be calculated in terms of the mean camera chroma relative to the mean ideal chroma in the CIE color metric (ΔE*00) as defined in 2000 by the CIE on the CIEXYZ chromaticity diagram.

Among many other themes, Leonardo da Vinci&rsquo, s Manuscript B contains several drawings of centrally planned churches, some of which are represented using a plan view paired with a bird&rsquo, s-eye view. The use of a bird&rsquo, s-eye instead of an elevation represents an innovative depiction technique, which allows combining the immediacy of the perspective view with the measurability of the fa&ccedil, ades, and therefore to describe the three-dimensionality of the buildings. To understand the reasons behind the use of this original technique, the edifices&rsquo, shape and classify them, we decided to use 3D digital reconstruction techniques, for their ability to avoid misunderstandings in the reconstruction process and in the results. This article describes the method to create the digital models of sixteen churches. A Visual Programming Language (VPL) script was used as the 3D base for modelling the churches achieved from a classification code expressing the aggregative rules of the churches. Then, the geometric process for the construction of the plan and its relationship with the elevation measures were studied for each church. Finally, this information was used for the completion of the 3D models, distinguishing more output variants each time there was an inconsistency between plan and perspective view, a variability of one architectural element or an uncertainty.

The color survey of Architectural and open-air Archaeological artefacts represents a difficult operation due to a lot of factors such as subjective aspects of visual perception, objective characteristics relating to sources of lighting and the way one watches something. The paper describes a method for 3D reality-based color managed modeling, aimed to render reflectance properties of artifacts with perceptual fidelity on many type of display. The method is based on an accurate color management system, from acquisition to visualization, in order to be used within a 3D acquisition pipeline, allowing simultaneous processing of color and shape data. The developed techniques are easy, low-cost, fast and could produce visually accurate images and 3D model, and, in order to avoid inaccuracies, a systematic quality control on the images acquired and 3D models rendered has been introduced. Results are presented about both processing accuracy and final 3D models visualization. The color survey, usually, refers to three methods, which are not able to ensure the correct perception of color on an RGB monitor or its faithful reproduction on a print support, and to assure a right color checking on a wide surface, and with a non-uniform color. The presented workflow and specific solutions appear today a good compromise between fidelity of reproduced data and ease of use of the developed tools.

none 6 no The sixteenth-century Fountain of Neptune is one of Bologna’s most renowned landmarks. During the recent restoration activities of the monumental sculpture group, consisting in precious marbles and highly refined bronzes with water jets, a photographic campaign has been carried out exclusively for documentation purposes of the current state of preservation of the complex. Nevertheless, the highquality imagery was used for a different use, namely to create a 3D digital model accurate in shape and color by means of automated photogrammetric techniques and a robust customized pipeline. This 3D model was used as basic tool to support many and different activities of the restoration site. The paper describes the 3D model construction technique used and the most important applications in which it was used as support tool for restoration: (i) reliable documentation of the actual state; (ii) surface cleaning analysis; (iii) new water system and jets; (iv) new lighting design simulation; (v) support for preliminary analysis and projectual studies related to hardly accessible areas; (vi) structural analysis; (vii) base for filling gaps or missing elements through 3D printing; (viii) high-quality visualization and rendering and (ix) support for data modelling and semantic-based diagrams. F. I. Apollonio; M. Ballabeni; S. Bertacchi; F. Fallavollita; R. Foschi; M. Gaiani F. I. Apollonio; M. Ballabeni; S. Bertacchi; F. Fallavollita; R. Foschi; M. Gaiani

none 4 no Checking the irreversible process of clean-up is a delicate task that requires a work of synthesis between theoretical knowledge and practical experience, to define an effective operating protocol on a limited patch area to be extended later to the entire artefact’s surface. In this paper, we present a new, quick, semi-automated 3D photogrammetry-based solution to support restorers in the open-air bronze artwork cleaning from corrosion and weathering decay. The solution allows the conservators to assess in real time and with a high level of fidelity in colour and shape, the ‘surfaces’ to be cleaned before, during and after the clear-out treatment. The solution besides allows an effective and valuable support tool for restorers to identify the original layer of the bronze surface, developed and validated during the ongoing restoration of the Neptune Fountain in Bologna. Apollonio, F. I.; Gaiani, M.; Basilissi, W.; Rivaroli, L. Apollonio, F. I.; Gaiani, M.; Basilissi, W.; Rivaroli, L.

Every day new tools and algorithms for automated image processing and 3D reconstruction purposes become available, giving the possibility to process large networks of unoriented and markerless images, delivering sparse 3D point clouds at reasonable processing time. In this paper we evaluate some feature-based methods used to automatically extract the tie points necessary for calibration and orientation procedures, in order to better understand their performances for 3D reconstruction purposes. The performed tests – based on the analysis of the SIFT algorithm and its most used variants – processed some datasets and analysed various interesting parameters and outcomes (e.g. number of oriented cameras, average rays per 3D points, average intersection angles per 3D points, theoretical precision of the computed 3D object coordinates, etc.).

Nowadays digital replicas of artefacts belonging to the Cultural Heritage (CH) are one of the most promising innovations for museums exhibitions, since they foster new forms of interaction with collections, at different scales. However, practical digitization is still a complex task dedicated to specialized operators. Due to these premises, this paper introduces a novel approach to support non-experts working in museums with robust, easy-to-use workflows based on low-cost widespread devices, aimed at the study, classification, preservation, communication and restoration of CH artefacts. The proposed methodology introduces an automated combination of acquisition, based on mobile equipment and visualization, based on Real-Time Rendering. After the description of devices used along the workflow, the paper focuses on image pre-processing and geometry processing techniques adopted to generate accurate 3D models from photographs. Assessment criteria for the developed process evaluation are illustrated. Tests of the methodology on some effective museum case studies are presented and discussed.

The paper presents a new technique for detecting and rendering the total appearance of a drawing with the aim of digitally visualizing fine drawing collections with perceptive accuracy. A drawing's total appearance can be measured using equipment commonly found in a photographic studio. The system consists of four strobes and an RGB camera. The appearance is defined by its spatially varying spectral reflectance factor, surface macrostructure and surface microstructure. Using stereo-photometric principles, images of each light source taken sequentially from 45° by the normal and annularly at each 90° angle (for four lights) were used to measure the surface normal and diffuse reflectance. An OpenGL viewer was written to render images for specific geometries and for studio lighting. The pipeline from acquisition to visualization was tested on the most famous drawing in existence, Leonardo da Vinci's Vitruvian Man.

Tools and algorithms for automated image processing and 3D reconstruction purposes have become more and more available, giving the possibility to process any dataset of unoriented and markerless images. Typically, dense 3D point clouds (or texture 3D polygonal models) are produced at reasonable processing time. In this paper, we evaluate how the radiometric pre-processing of image datasets (particularly in RAW format) can help in improving the performances of state-of-the-art automated image processing tools. Beside a review of common pre-processing methods, an efficient pipeline based on color enhancement, image denoising, RGB to Gray conversion and image content enrichment is presented. The performed tests, partly reported for sake of space, demonstrate how an effective image pre-processing, which considers the entire dataset in analysis, can improve the automated orientation procedure and dense 3D point cloud reconstruction, even in case of poor texture scenarios.

In the last years the image-based pipeline for 3D reconstruction purposes has received large interest leading to fully automated methodologies able to process large image datasets and deliver 3D products with a level of detail and precision variable according to the applications. Different open issues still exist, in particular when dealing with the 3D surveying and modeling of large and complex scenarios, like historical porticoes. The paper presents an evaluation of various surveying methods for the geometric documentation of ca 40km of historical porticoes in Bologna (Italy). Finally, terrestrial photogrammetry was chosen as the most flexible and productive technique in order to deliver 3D results in form of colored point clouds or textured 3D meshes accessible on the web. The presented digital products are a complementary material for the final candidature of the porticoes as UNESCO WHS.

The paper presents a critical analysis regarding the methodological approach useful to produce 3D digital contents of Cultural Heritage artifacts in context of Digital Archives. The structure of 3D model and the reconstruction process are analyzed in order to elaborate and formalize semantic knowledge concerning the work of art, object of study. Some experiences recently carried-out can showt he development of some web-based platform able to allow the use of contents properly related to the characteristics of the case study.

Restoration is becoming a quite complex process: a large number of internal and external variables co-exist and may impair it. Among these, the large number of professionals involved and the huge amount of documentation produced can heavily affect the quality of the intervention as well as the possibility to have systemic and informed interventions in the future. In particular, a standardized method for storing restoration data and accessing them is still lacking, and the use of new technologies is still limited and/or not scalable. The paper describes the process of designing and testing an information system (IS) based on three-dimensional (3D) data, aimed to support the restoration of Neptune's Fountain in Bologna. In preparation of the restoration, a major effort was carried out to design and implement a web-based IS able to host all of the data produced, to allow the conservation-restoration specialists to interact on-site with an accurate 3D representation of the elements of the fountain, and to directly reference all information and data produced on the geometry of the model. The paper focuses on the challenges and adopted solutions related to the use of 3D models and the data mapping on 3D surfaces in the context of restoration documentation. Highly detailed visualizations of the models, easy navigation, and usable functionalities to add information directly on the 3D model have been achieved by extending the available solutions and by implementing new mechanisms to overcome the limitations of WebGL and remote rendering. Neptune IS’ development has been extensively experimented in a real context of use. Results and knowledge from the experimentation currently represents the basis for evolving Neptune IS into a possible generic and flexible platform for documentation management in the field of restoration and related methodologies.

The SACHER project provides a distributed, open source and federated cloud platform able to support the life-cycle management of various kinds of data concerning tangible Cultural Heritage. The paper describes the SACHER platform and, in particular, among the various integrated service prototypes, the most important ones to support restoration processes and cultural asset management: (i) 3D Life Cycle Management for Cultural Heritage (SACHER 3D CH), based on 3D digital models of architecture and dedicated to the management of Cultural Heritage and to the storage of the numerous data generated by the team of professionals involved in the restoration process; (ii) Multidimensional Search Engine for Cultural Heritage (SACHER MuSE CH), an advanced multi-level search system designed to manage Heritage data from heterogeneous sources.

The paper, aiming to retrieve the original meaning of Smart City, attempts to demonstrate its impact in the field of Cultural Heritage (CH). It presents a framework - applied in a project for a prototypical case study of ‘Widespread Built Heritage’ (WBH) - to create a Smart cultural city, transforming Cultural Items into Smart Cultural Objects (SCO), meant as sources and recipients of advanced information. The framework aims to provide an extensive and robust theoretical support to design and to manage the processes of Cultural Objects (CO) and Cultural bins, implementing a methodological system and an advanced environment based on Smart technologies.

The current Cultural Heritage management system lacks of ICT platforms for the management and integration of heterogeneous and fragmented data sources and interconnection between private and public subjects involved in the process. The SACHER project intends to fill this gap, working both on a technological level and on a business model level: firstly providing a platform based on an open-source distributed cloud-computing environment for the management of the complete data lifecycle related to cultural assets; moreover providing new models based on participatory design for Cultural Heritage data directed towards social entrepreneurship. This paper presents the first implementation of a system for managing data based on the 3D model of the cultural object, with a focus on the process for cultural assets management and the interface design for cultural services.

none 4 Ensuring color fidelity in image-based 3D modeling of heritage scenarios is nowadays still an open research matter. Image colors are important during the data processing as they affect algorithm outcomes, therefore their correct treatment, reduction and enhancement is fundamental. In this contribution, we present an automated solution developed to improve the radiometric quality of an image datasets and the performances of two main steps of the photogrammetric pipeline (camera orientation and dense image matching). The suggested solution aims to achieve a robust automatic color balance and exposure equalization, stability of the RGB-to-gray image conversion and faithful color appearance of a digitized artifact. The innovative aspects of the article are: complete automation, better color target detection, a MATLAB implementation of the ACR scripts created by Fraser and the use of a specific weighted polynomial regression. A series of tests are presented to demonstrate the efficiency of the developed methodology and to evaluate color accuracy ('color characterization'). Gaiani, Marco; Apollonio, Fabrizio Ivan; Ballabeni, Andrea; Remondino, Fabio Gaiani, Marco; Apollonio, Fabrizio Ivan; Ballabeni, Andrea; Remondino, Fabio

Information and communication technology applications and the preservation, research and popularisation of heritage have attained an important position in the conservation, heritage management and art studies of cultural heritage. As cultural heritage has a lot of different aspects and there is often a need of continuous scientific research and preservation to gather valuable information from our history and provide better understanding for future generations. Although there have been numerous projects around the world, over the past four years become combination of several technical analysis very important cultural heritage documentation solution in Estonia. Supporting that development is the wider knowledge and better accessibility of the instrumental studies, imaging and survey technologies. Combination of non-destructive and destructive surveys provides enriched information about heritage artefacts that may considerably help conservation and heritage specialists especially when it is accessible over the Web. In these following cases study of research connected with art, we tested and used different imaging and information technologies and the possibilities that may in the future be applied in the landscape of museums and cultural heritage protection for improved documentation of Estonia’s heritage.

ICT-based technological innovation has not yet made substantial advantages, although desirable, in the Cultural Heritage field, both as regards the management and as regards the use of assets. It is still weak, e.g., the receipt of the paradigm of the Internet of Things (IoT). Conversely ICT-based technologies could play a main role. I.e. in the following, we discuss how IoT can make a valuable contribution to emphasize the knowledge processes through augmentation of past memories with information interfaces and allows a complete management of the Heritage artefact from conservation to communication.

Automated image-based 3D reconstruction methods are more and more flooding our 3D modeling applications. Fully automated solutions give the impression that from a sample of randomly acquired images we can derive quite impressive visual 3D models. Although the level of automation is reaching very high standards, image quality is a fundamental pre-requisite to produce successful and photo-realistic 3D products, in particular when dealing with large datasets of images. This article presents an efficient pipeline based on color enhancement, image denoising, color-to-gray conversion and image content enrichment. The pipeline stems from an analysis of various state-of-the-art algorithms and aims to adjust the most promising methods, giving solutions to typical failure causes. The assessment evaluation proves how an effective image pre-processing, which considers the entire image dataset, can improve the automated orientation procedure and dense 3D point cloud reconstruction, even in the case of poor texture scenarios.

The chapter presents the methodology that has been adopted to develop a process for acquiring knowledge that is able to note and make the analysis of preliminary data and interpretation criteria used through a 3D modeling reconstructive process understandable. The classification schemes and criteria adopted aimed to validate the entire process, giving us the ability to visually assess the proper level of knowledge related to the reconstructive process, with its flaws and lacunae, and to carry out comparative operations on the set of data and information held.

Nowadays cities, as well as Cultural Heritage, are facing new challenges due to the public financial straits and the increasing need to deliver innovative service to manage a wide heritage. Great expectations are in put the Smart City paradigm relying on the capability of the city to realize and scale up intangible infrastructures based on new typologies of partnerships for the development of services. The paper presents a design framework aimed to transform Cultural Items in Smart Cultural Objects (SCO), meant as sources and recipients of advanced information applied on ‘Widespread Built Cultural Heritage’. The aim has been not just to enhance the artifacts with their own quality, but their unique social, communal, anthropological and urban-infrastructural meaning. The ability to manage efficiently heterogeneous data and the levels of global connectivity, as well as the real-time interaction, perception, localization, communication, and identification, made possible by cloud computing and Internet of Things, to allow the changeover from Cultural Objects to SCO. The framework, here exposed, aims to provide an extensive and robust theoretical support to design and to manage the processes of Cultural Objects and Cultural bins, implementing a methodological system and an advanced environment based on ICT technologies for recording, storage, processing, access and presentation of Cultural Heritage (CH) data in a Smart Management environment. The framework has been applied in two projects for a prototypical case study of widespread urban CH. Keywords: cultural heritage, human smart city, co-design, internet of things, heritage management and communication.

[EN] The paper describes a color enhanced processing system - applied as case study on an artifact of the Pompeii archaeological area - developed in order to enhance different techniques for reality-based 3D models construction and visualization of archaeological artifacts. This processing allows rendering reflectance properties with perceptual fidelity on a consumer display and presents two main improvements over existing techniques: a. the color definition of the archaeological artifacts; b. the comparison between the range-based and photogrammetry-based pipelines to understand the limits of use and suitability to specific objects. [ES] El documento describe un sistema mejorado de procesamiento de color, aplicado como caso de estudio sobre un artefacto de la zona arqueológica de Pompeya. Este sistema se ha desarrollado con la finalidad de mejorar las diferentes técnicas para la construcción de modelos 3D basados sobre datos de la realidad y para la visualización de artefactos arqueológicos. Este proceso permite visualizar las propiedades de reflectancia con fidelidad perceptible en una pantalla de usuario y presenta dos mejoras principales respecto a las técnicas existentes:a. la definición del color de los artefactos arqueológicos;b. la comparación entre los flujos de trabajo basados en range-based-modeling y en fotogrametría, para entender los límites de uso y la adecuación a los objetos específicos.

The paper presents a novel digital 3D GIS web-based system entirely founded on Google Earth, built to offer a deep insight into Palladio's opera for restitution of its architectural surveys, reconstruction for historical reasons, analysis for structural and other options, and assembly and presentation of all certified Palladian documentation. The development of the application follows the philosophy of visual computing and it is based on an architectural knowledge representation. The information system is conceived as a typical Rich Internet Application and it is based on the digitalization of the complete Palladian corpus documentation implemented by the Centro Internazionale di Studi di Architettura Andrea Palladio (CISAAP). The 3D geodatabase system is, actually, in use at the Centro as the Palladian information system for researchers and in two expositions at Barbaran da Porto Palace in Vicenza, and at Villa Poiana at Poiana Maggiore, where is widely used by tourists for virtual visits to Palladian buildings.

The paper presents some experiments carried out as part of the virtual reconstruction of buildings just documented by partial sketches, or partially built, or no more existing, with the aim (a) to emphasize the use of a semantic construction of the digital model, not only as a means to modeling a building but as a cognitive system, (b) to show conceptual similarity between the treaties and BIM, (c) to propose new and more robust solutions to the 3D modeling from 2D drawings for CH artifacts, able to allow the verification of the assumptions used during the reconstruction pipeline, (d) to make use of interactive technical reference, typically real-time photorealistic rendering, for the visualization of three-dimensional model and of variants snapshots, managed by an iconic for illustrating the method of comparison and guided reading of model’s characters of the steps taken.