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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.

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.

El documento describe una metodología que cubre los procedimientos de levantamiento y las aplicaciones informáticas con el objetivo de convertir herramientas generalistas (teléfonos inteligentes) en dispositivos de adquisición rigurosa de BIC almacenados en los museos. Dos problemas diferentes se enfrentan: a) como las caracteristicas de dichos objetos a escala micro/meso afectan su documentación; b) desarrollo de una solución multipropósito para una adquisición de bajo costo y fácil de usar para digitalizar y visualizar artefactos BIC. Se presenta un procedimiento basado en un kit de adquisición digital destinado a lograr modelos y texturas confiables, así como representaciones de color precisas. Se han seleccionado varios objetos para probar la coherencia y flexibilidad de los métodos y técnicas propuestos, y los resultados se comparan con los de las técnicas de adquisición estándar.

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.

Digital Cultural Heritage and Digital Humanities are, historically seen, in focus of different communities as well as approaching different research topics and - from an organizational point of view - departments. However, are they that different? The idea of this joint article involving digital humanists and heritage researchers is to examine communities, concepts and research applications as well as shared challenges. Beyond a collection of problem-centred essays this is intended to initiate a fruitful discussion about commonalities and differences between both scholarly fields as well as to assess to which extent they are two sides of the same medal.

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.

On the occasion of the recent restoration of the sixteenth century Neptune’s Fountain in Bologna, promoted by the municipality in 2015 to preserve one of the major town’s landmark, high-quality imagery has been acquired for documenting the current state of preservation of the marble and bronze surfaces before and during the restoration phases. Starting from this available detailed photographic campaign and using new tools developed to solve problems linked with some limitations of the captured imagery, authors produced a photogrammetry-based 3D model of the monumental sculpture group, reliable for both geometric features and colour reproduction consistency, in order to be used to support the supplementary activities not foreseen in the original project. The paper presents methods and techniques implemented to produce the 3D model of the fountain, besides its main actual applications as a basic tool to support different restoration activities: (i) reliable documentation of the actual state; (ii) high-quality visualization and rendering; (iii) technical outcomes and graphical representation extraction; (iv) study of original and current water supply system and simulation of the new project for the jets system and watergames; (v) new lighting design simulation; (vi) structural analysis; (vii) support to preliminary analysis and design studies related to hardly accessible areas; (viii) surface cleaning analysis; (ix) base for filling gaps or missing elements through 3D printing; (x) support for data modelling and semantic-based diagrams.

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.

Building Information Modeling (BIM) has attracted wide interest in the field of documentation and conservation of Architectural Heritage (AH). Existing approaches focus on converting laser scanned point clouds to BIM objects, but laser scanning is usually limited to planar elements which are not the typical state of AH where free-form and double-curvature surfaces are common. We propose a method that combines low-cost automatic photogrammetric data acquisition techniques with parametric BIM objects founded on Architectural Treatises and a syntax allowing the transition from the archetype to the type. Point clouds with metric accuracy comparable to that from laser scanning allows accurate as-built model semantically integrated with the ideal model from parametric library. The deviation between as-built model and ideal model is evaluated to determine if feature extraction from point clouds is essential to improve the accuracy of as-built BIM.

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

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.