Geometric and Optic Characterization of a Hemispherical Dome Port for Underwater Photogrammetry

The popularity of automatic photogrammetric techniques has promoted many experiments in underwater scenarios leading to quite impressive visual results, even by non-experts. Despite these achievements, a deep understanding of camera and lens behaviors as well as optical phenomena involved in underwater operations is fundamental to better plan field campaigns and anticipate the achievable results. The paper presents a geometric investigation of a consumer grade underwater camera housing, manufactured by NiMAR and equipped with a 7'' dome port. After a review of flat and dome ports, the work analyzes, using simulations and real experiments, the main optical phenomena involved when operating a camera underwater. Specific aspects which deal with photogrammetric acquisitions are considered with some tests in laboratory and in a swimming pool. Results and considerations are shown and commented

3D MODELING AND VIRTUAL APPLICATIONS FOR THE VALORIZATION OF HISTORICAL HERITAGE

[EN] A large amount of 3D digital models, acquired with reality-based techniques or modelled with CAAD methods, are today part of archaeological studies. This new form of heritage documentation has deeply changed the traditional way of representing, studying and visualizing the remains of the past. At the same time, 3D digital documentation is rarely shared and easily accessible, so as the historical iconographic sources, text documents and other information used forinterpreting remains and for validating 3D reconstructions. This paper describes the first results of an interdisciplinary project of 3D documentation and valorization of historical heritage, carried out in the archaeological site of Pausilypon (Naples, Italy). The final aim is to realize an integrated virtual tour of the site, developed in Unity 3D, based on 3D surveying products. This tour proposes a new way of presenting and visualizing results of archaeological studies and 3D documentation, collecting and overlapping different types of data in a unique and interactive virtual environment. Besides 360° equi-rectangular panoramic image and 3D models, heterogeneous material will help users to understand the interpretative process followed for the hypothetical CAAD reconstruction. These results will be mainly shared via web, for a larger dissemination of the work and for supporting future research on the site. In addition, for promoting the knowledge of the archaeological remains, a simplified and immersive tour will be developed for Virtual Reality devices.Farella, E.; Menna, F.; Remondino, F.; Campi, M. (2016). 3D MODELING AND VIRTUAL APPLICATIONS FOR THE VALORIZATION OF HISTORICAL HERITAGE. En 8th International congress on archaeology, computer graphics, cultural heritage and innovation. Editorial Universitat Politècnica de València. 456-459. http://hdl.handle.net/10251/85988OCS45645

INVESTIGATING 3D RECONSTRUCTION OF NON-COLLABORATIVE SURFACES THROUGH PHOTOGRAMMETRY AND PHOTOMETRIC STEREO

Abstract. 3D digital reconstruction techniques are extensively used for quality control purposes. Among them, photogrammetry and photometric stereo methods have been for a long time used with success in several application fields. However, generating highly-detailed and reliable micro-measurements of non-collaborative surfaces is still an open issue. In these cases, photogrammetry can provide accurate low-frequency 3D information, whereas it struggles to extract reliable high-frequency details. Conversely, photometric stereo can recover a very detailed surface topography, although global surface deformation is often present. In this paper, we present the preliminary results of an ongoing project aiming to combine photogrammetry and photometric stereo in a synergetic fusion of the two techniques. Particularly, hereafter, we introduce the main concept design behind an image acquisition system we developed to capture images from different positions and under different lighting conditions as required by photogrammetry and photometric stereo techniques. We show the benefit of such a combination through some experimental tests. The experiments showed that the proposed method recovers the surface topography at the same high-resolution achievable with photometric stereo while preserving the photogrammetric accuracy. Furthermore, we exploit light directionality and multiple light sources to improve the quality of dense image matching in poorly textured surfaces

ACCURACY AND BLOCK DEFORMATION ANALYSIS IN AUTOMATIC UAV AND TERRESTRIAL PHOTOGRAMMETRY – LESSON LEARNT –

International audience; The paper rep orts the results of an integrated Unmanned Aerial Vehicle (UAV) and terrestrial photogrammetric survey realized in the archaeological site of the Roman theatre in Ventimiglia, Italy. The main deliverables were 2D drawings at scale 1:20, which required a Ground Sample Distance (GSD) less than 4 mm and, consequently, accuracy better than 4 mm. The UAV was employed to acquire both vertical and oblique images, while the terrestrial imaging acquisition was realized with the aim of generating separate dense point clouds of some vertical structures, corresponding to the sections required. The variability of results with automatic photogrammetric procedures against different image network configurations, with and without ground control, are analyzed and presented

3D virtualization of an underground semi-submerged cave system

Underwater caves represent the most challenging scenario for exploration, mapping and 3D modelling. In such complex environment, unsuitable to humans, highly specialized skills and expensive equipment are normally required. Technological progress and scientific innovation attempt, nowadays, to develop safer and more automatic approaches for the virtualization of these complex and not easily accessible environments, which constitute a unique natural, biological and cultural heritage. This paper presents a pilot study realised for the virtualization of 'Grotta Giusti' (Fig. 1), an underground semi-submerged cave system in central Italy. After an introduction on the virtualization process in the cultural heritage domain and a review of techniques and experiences for the virtualization of underground and submerged environments, the paper will focus on the employed virtualization techniques. In particular, the developed approach to simultaneously survey the semi-submersed areas of the cave relying on a stereo camera system and the virtualization of the virtual cave will be discussed

Kinect Fusion improvement using depth camera calibration

Scene's 3D modelling, gesture recognition and motion tracking are fields in rapid and continuous development which have caused growing demand on interactivity in video-game and e-entertainment market. Starting from the idea of creating a sensor that allows users to play without having to hold any remote controller, the Microsoft Kinect device was created. The Kinect has always attract researchers in different fields, from robotics to Computer Vision (CV) and biomedical engineering as well as third-party communities that have released several Software Development Kit (SDK) versions for Kinect in order to use it not only as a game device but as measurement system. Microsoft Kinect Fusion control libraries (firstly released in March 2013) allow using the device as a 3D scanning and produce meshed polygonal of a static scene just moving the Kinect around. A drawback of this sensor is the geometric quality of the delivered data and the low repeatability. For this reason the authors carried out some investigation in order to evaluate the accuracy and repeatability of the depth measured delivered by the Kinect. The paper will present a throughout calibration analysis of the Kinect imaging sensor, with the aim of establishing the accuracy and precision of the delivered information: a straightforward calibration of the depth sensor in presented and then the 3D data are correct accordingly. Integrating the depth correction algorithm and correcting the IR camera interior and exterior orientation parameters, the Fusion Libraries are corrected and a new reconstruction software is created to produce more accurate models

The hidden burden of food waste: The double energy waste in Italy

The energy intensity of modern food systems represents a major issue in a scenario of decreasing oil resources and increasing population. Beside the use of renewable energy, an increased efficiency in food systems could contribute to reduce fossil fuels dependence. In this sense, food losses and waste (FLW) have crucial consequences on the energy balance. Based on the concept of "embodied energy", food wastage can be framed as a double waste of energy, both in terms of non-consumed food energy and the inputs used for production. Secondary data regarding direct and indirect energy inputs and FLW have been collected for the Italian food chain to estimate the embodied energy of food waste. Since in 2011 the production and distribution of food implied the use of 822 PJ and 18 Mt of food was discarded, 67 PJ of food energy and 100 PJ of embodied energy were wasted. These figures are equivalent to 12.2% of the total nutritional energy output and to 1.3% of the final energy use in Italy, respectively. The concept of double energy waste sheds new light on the intertwined relationship between energy and food security, suggesting that appropriate food waste reduction policies could result in a higher food production level and relevant energy savings

Valorisation of history and landscape for promoting the memory of WWI

10 p.In recent years many activities were conducted to commemorate the 100th Anniversary of the FirstWorld War (WWI) outbreak. Among these, the valorisation of history and landscape (VAST) project(http://vast.fbk.eu) was part of the initiatives promoted by the Autonomous Province of Trento (Italy)as a tribute to WWI events in the region. The project was primarily aimed to document and promote,through 3D digitization approaches, ICT technologies and communication material, the memory of sites,theatre of the world conflict. The Trento’s area was under the Austro-Hungarian Empire until the end ofWWI and on the border with the Italian Kingdom. The area represented a crucial and bloody war frontbetween the Austrian and Italian territories. It was thus constellated of military fortresses, trenches andtunnels, most of them now ruined and at risk to slowly disappear. 3D surveying and modelling techniqueswere exploited to produce 3D digital models of structures and objects, along with virtual tours, dissem-ination material and a WebGIS of the area. All the products are now used for restoration, valorisation,educational and communication purposesS

Flexible Photogrammetric Computations Using Modular Bundle Adjustment: The Chain Rule and the Collinearity Equations

International audienceThe main purpose of this paper is to show that photogrammetric bundle adjustment computations can be sequentially organized into modules. Furthermore, the chain rule can be used to simplify the computation of the analytical Jacobians needed by the adjustment. Novel projection models can be flexibly evaluated by inserting, modifying, or swapping the order of selected modules. As a proof of concept, two variants of the pin-hole projection model with Brown lens distortion were implemented in the open-source Damped Bundle Adjustment Toolbox (DBAT) and applied to simulated and calibration data for a non-conventional lens system. The results show a significant difference for the simulated, error-free, data but not for the real calibration data. The current flexible implementation incurs a performance loss. However, in cases where flexibility is more important, the modular formulation should be a useful tool to investigate novel sensors, data processing techniques, and refractive models

A combined framework for the life cycle assessment and costing of food waste prevention and valorization: an application to school canteens

About one third of global edible food is lost or wasted along the supply chain, causing the wastage of embedded natural and economic resources. Life cycle methodologies can be applied to identify sustainable and viable prevention and valorization routes needed to prevent such inefficiencies. However, no systemic approach has been developed so far to guide practitioners and stakeholders. Specifically, the goal and scoping phase (e.g. problem assessed or system function) can be characterized by a large flexibility, and the comparability between food waste scenarios could be not ensured. Within the Horizon2020 project Resource Efficient Food and dRink for the Entire Supply cHain, this study aimed to provide practitioners with guidance on how to combine life cycle assessment and environmental life cycle costing in the context of food waste. Recent literature was reviewed to identify relevant methodological aspects, possible commonly adopted approaches, main differences among studies and standards and protocols, main challenges, and knowledge gaps. Basing on this review, an analytical framework with a set of recommendations was developed encompassing different assessment situations. The framework intends to provide a step by step guidance for food waste practitioners, and it is composed of a preliminary section on study purpose definition, three decision trees\u2014respectively on assessment situation(s), costing approach, and type of study (footprint vs. intervention)\u2014and two sets of recommendations. Recommendations can be applied to all levels of the food waste hierarchy, stating a generic order of preference for handling food chain side flows. This consistent and integrated life cycle approach should ensure a better understanding of the impact of specific interventions, thus supporting informed private and public decision making and promoting the design of sustainable and cost-efficient interventions and a more efficient food supply chains