scholarly journals Image-based techniques for the survey of mosaics in the St Mark's Basilica in Venice

2018 ◽  
Vol 9 (19) ◽  
pp. 1 ◽  
Author(s):  
Andrea Adami ◽  
Francesco Fassi ◽  
Luigi Fregonese ◽  
Mario Piana

<p>This article aims to critically examine the entire methodology of very large scale (1:1) surveying and documentation of mosaic surfaces. The term ‘survey’ should be read in its broadest and most complete and sense, including the phases of measurement and data processing as well as management and use of these data for the purposes of preservation and maintenance. The case study presented here took place at St Mark’s Basilica (<em>Basilica di San Marco</em>), in Venice, where mosaic flooring, wall and vault decorations have been surveyed on two separate occasions. These two experiences shared a common goal (a full-scale survey of the mosaic decorations) but differed in terms of the methodologies used, chiefly due to the technological developments of recent years. All this, therefore, lends itself to a methodological reflection and critique of the ways in which surveying technology has evolved over time. It enables to conduct surveys that would, just a few years ago, have been inconceivable due to their size and complexity. This article describes in detail current surveying processes, which includes the use of a multi-scale “image-based” approach, “re-topology” methods such as non-uniform rational B-spline (NURBS) and a tailor-made Building Information Modeling (BIM) system. This system allows the direct use of a three-dimensional (3D) model of the Basilica within the maintenance process of the monument itself with the options to georeferencing information, extract basic metric data and catalogue all its mosaics.</p><p><strong>Highlights:</strong></p><ul><li><p>Modern digital photogrammetric techniques enable the acquisition of very complex objects, not only in terms of form but also in terms of material.</p></li><li><p>To obtain high resolution orthophotos, it is necessary to accurately take care of all the stages of the process: photographic acquisition, surveying, modelling and orthographic reprojection.</p></li><li><p>High resolution images and detailed 3D models can benefit from a complex BIM system for the management of all data.</p></li></ul>

2021 ◽  
Vol 2094 (3) ◽  
pp. 032031
Author(s):  
V I Zhadanov ◽  
I N Charikova ◽  
V M Shardakov

Abstract Building information modeling provides an integrated three-dimensional environment applied to the management of large-scale engineering projects, allowing you to reduce the cost and time for planning structures and requirements for the reliability of buildings. The purpose of this work is to develop a methodology for changing the layout and reliability factor during the visualization of three-dimensional models to improve the analysis of building plans. This approach will allow you to combine different analytical methods and approaches when planning different structures. The results of this work suggest new directions for future research in the field of information visualization for the construction complex. The system is compatible with portable and scalable mobile devices. The proposed system can also be used for pre-project architecture and augmented visualization, where proprietary developed methods are used to achieve the quality of photorealistic rendering.


2019 ◽  
Vol 4 (1) ◽  
pp. 8 ◽  
Author(s):  
José Neves ◽  
Zita Sampaio ◽  
Manuel Vilela

Building Information Modeling (BIM) is an Industry 4.0 methodology that is increasingly used in the domain of Architecture, Engineering, and Construction (AEC). BIM emerges as a new methodology, one that is more collaborative and based on parametric three-Dimensional (3D) models, centralizing different types of information of a geometric, physical, and economic nature. The purpose of this paper is to analyze the application of the BIM methodology to a rail track rehabilitation case study using a geotextile and geogrid in the ballast layer base. The creation of the 3D and 4D BIM models was performed using various BIM-based tools, which made it possible to achieve the spatial and parametric representation of the rail track and the simulation of the main construction tasks. A new BIM object pertaining to the rail track was created. This paper describes the procedures applied in achieving the BIM models, the limitations involved, and the interoperability between the BIM tools. Additionally, the potential for information extraction with respect to the infrastructure design, construction, and operation, e.g., planning and scheduling, quantities, graphic outputs, and track geometry quality, was demonstrated. It was concluded that the BIM methodology was viable and could be implemented with benefits, despite certain difficulties and limitations, which emphasize the need for further developments.


Author(s):  
J. Suziedelyte Visockiene ◽  
E. Tumeliene

<p><strong>Abstract.</strong> The implementation of Building Information Modelling (BIM) in each project, which is planned, have a design and construction stages. In the construction stage the objects are modelled by architects, engineers, and surveyors. Modelling process allowed to construct a BIM, which replaces two-dimensional (2D) building information into a three-dimensional (3D). Noticed that 3D BIM created by surveyors is not the same as 3D BIM, which is created by architects. Therefore, the purpose of this study is to identify the differences of the created 2D draftings made by 3D models between surveyors and architect’s. The surveyors make their model by using Unnamed Aerial Vehicle (UAV) system: Airborne Drone Data and Data photogrammetric processing technology. The 3D models accuracy is assessed by UAV images processing. The 3D information should be used to calculate façade geometry, volume, distances, contours, which are in the shadowed side of the house, and create 2D façade draftings. Traditionally, architects used 2D building’s façade draftings for pre-design in Construction Projects (CP). 3D architectural model is created by using structural 2D draftings created with Autodesk software. The architectural 3D model is more convenient for the general design and the visual view, it is easily to evaluate the impact of the changes that will be made. The 3D architectural model helps to finish a project at a low cost and also to evaluate the effect of the changes made. The 3D model from surveys measurements shows real view of an object (with deformations), meanwhile the 3D model from architects is a corrected image. Discrepancies between surveyors and architect’s 2D models made by 3D virtual reality (VR) are analysed in this article.</p>


Author(s):  
M. Breunig ◽  
A. Borrmann ◽  
E. Rank ◽  
S. Hinz ◽  
T. Kolbe ◽  
...  

Computer-aided collaborative and multi-scale 3D planning are challenges for complex railway and subway track infrastructure projects in the built environment. Many legal, economic, environmental, and structural requirements have to be taken into account. The stringent use of 3D models in the different phases of the planning process facilitates communication and collaboration between the stake holders such as civil engineers, geological engineers, and decision makers. This paper presents concepts, developments, and experiences gained by an interdisciplinary research group coming from civil engineering informatics and geo-informatics banding together skills of both, the Building Information Modeling and the 3D GIS world. New approaches including the development of a collaborative platform and 3D multi-scale modelling are proposed for collaborative planning and simulation to improve the digital 3D planning of subway tracks and other infrastructures. Experiences during this research and lessons learned are presented as well as an outlook on future research focusing on Building Information Modeling and 3D GIS applications for cities of the future.


Author(s):  
F. Carvajal-Ramírez ◽  
P. Martínez-Carridondo ◽  
L. Yero-Paneque ◽  
F. Agüera-Vega

<p><strong>Abstract.</strong> Three-dimensional (3D) models have become a great source of data for the conservation, reconstruction, and documentation of emblematic buildings of cultural heritage. In this study, photogrammetry based on <i>Unmanned Aerial Vehicles (UAVs)</i> was applied to perform a photogrammetric survey of a dilapidated cultural heritage building. On the basis of this survey and the historical information gathered from the building, its virtual reconstruction has been carried out using a <i>Historic Building Information Modeling (HBIM)</i>; applying realistic materials and textures in order to document it.</p>


Author(s):  
Thomas H. Kolbe ◽  
Andreas Donaubauer

AbstractSemantic 3D city modeling and building information modeling (BIM) are methods for modeling, creating, and analyzing three-dimensional representations of physical objects of the environment. Digital modeling of the built environment has been approached from at least four different domains: computer graphics and gaming, planning and construction, urban simulation, and geomatics. This chapter introduces the similarities and differences of 3D models from these disciplines with regard to aspects like scale, level of detail, representation of spatial and semantic characteristics, and appearance. Exemplified by the international standards CityGML and Industry Foundation Classes (IFC), information models from semantic 3D city modeling and BIM and their corresponding modeling approaches are explored, and the relationships between them are discussed. Based on use cases from infrastructure planning, approaches for integrating information from semantic 3D city modeling and BIM, such as semantic transformation between CityGML and IFC, are described. Furthermore, the role of semantic 3D city modeling and BIM for recent developments in urban informatics, such as smart cities and digital twins, is investigated and illustrated by real-world examples.


Author(s):  
Kenneth H. Downing ◽  
Hu Meisheng ◽  
Hans-Rudolf Went ◽  
Michael A. O'Keefe

With current advances in electron microscope design, high resolution electron microscopy has become routine, and point resolutions of better than 2Å have been obtained in images of many inorganic crystals. Although this resolution is sufficient to resolve interatomic spacings, interpretation generally requires comparison of experimental images with calculations. Since the images are two-dimensional representations of projections of the full three-dimensional structure, information is invariably lost in the overlapping images of atoms at various heights. The technique of electron crystallography, in which information from several views of a crystal is combined, has been developed to obtain three-dimensional information on proteins. The resolution in images of proteins is severely limited by effects of radiation damage. In principle, atomic-resolution, 3D reconstructions should be obtainable from specimens that are resistant to damage. The most serious problem would appear to be in obtaining high-resolution images from areas that are thin enough that dynamical scattering effects can be ignored.


2012 ◽  
Vol 42 (1) ◽  
pp. 18-38 ◽  
Author(s):  
G. Roullet ◽  
J. C. McWilliams ◽  
X. Capet ◽  
M. J. Molemaker

Abstract High-resolution simulations of β-channel, zonal-jet, baroclinic turbulence with a three-dimensional quasigeostrophic (QG) model including surface potential vorticity (PV) are analyzed with emphasis on the competing role of interior and surface PV (associated with isopycnal outcropping). Two distinct regimes are considered: a Phillips case, where the PV gradient changes sign twice in the interior, and a Charney case, where the PV gradient changes sign in the interior and at the surface. The Phillips case is typical of the simplified turbulence test beds that have been widely used to investigate the effect of ocean eddies on ocean tracer distribution and fluxes. The Charney case shares many similarities with recent high-resolution primitive equation simulations. The main difference between the two regimes is indeed an energization of submesoscale turbulence near the surface. The energy cycle is analyzed in the (k, z) plane, where k is the horizontal wavenumber. In the two regimes, the large-scale buoyancy forcing is the primary source of mechanical energy. It sustains an energy cycle in which baroclinic instability converts more available potential energy (APE) to kinetic energy (KE) than the APE directly injected by the forcing. This is due to a conversion of KE to APE at the scale of arrest. All the KE is dissipated at the bottom at large scales, in the limit of infinite resolution and despite the submesoscales energizing in the Charney case. The eddy PV flux is largest at the scale of arrest in both cases. The eddy diffusivity is very smooth but highly nonuniform. The eddy-induced circulation acts to flatten the mean isopycnals in both cases.


2005 ◽  
Vol 38 (2) ◽  
pp. 260-265 ◽  
Author(s):  
Leonore Wiehl ◽  
Jens Oster ◽  
Michael Huth

Epitaxially grown Mo films on a faceted corundum (α-Al2O3)mplane were investigated by transmission electron microscopy. Low- and high-resolution images were taken from a cross-section specimen cut perpendicular to the facets. It was possible to identify unambiguously the crystallographic orientation of these facets and explain the considerable deviation (∼10°) of the experimental interfacet angle, as measured with atomic force microscopy (AFM), from the expected value. For the first time, proof is given for a smooth \{10\bar{1}1\} facet and a curvy facet with orientation near to \{10\bar{1}\bar{2}\}. Moreover, the three-dimensional epitaxial relationship of an Mo film on a faceted corundummsurface was determined.


Author(s):  
Zhao Sun ◽  
Yifu Wang ◽  
Lei Pan ◽  
Yunhong Xie ◽  
Bo Zhang ◽  
...  

AbstractPine wilt disease (PWD) is currently one of the main causes of large-scale forest destruction. To control the spread of PWD, it is essential to detect affected pine trees quickly. This study investigated the feasibility of using the object-oriented multi-scale segmentation algorithm to identify trees discolored by PWD. We used an unmanned aerial vehicle (UAV) platform equipped with an RGB digital camera to obtain high spatial resolution images, and multi-scale segmentation was applied to delineate the tree crown, coupling the use of object-oriented classification to classify trees discolored by PWD. Then, the optimal segmentation scale was implemented using the estimation of scale parameter (ESP2) plug-in. The feature space of the segmentation results was optimized, and appropriate features were selected for classification. The results showed that the optimal scale, shape, and compactness values of the tree crown segmentation algorithm were 56, 0.5, and 0.8, respectively. The producer’s accuracy (PA), user’s accuracy (UA), and F1 score were 0.722, 0.605, and 0.658, respectively. There were no significant classification errors in the final classification results, and the low accuracy was attributed to the low number of objects count caused by incorrect segmentation. The multi-scale segmentation and object-oriented classification method could accurately identify trees discolored by PWD with a straightforward and rapid processing. This study provides a technical method for monitoring the occurrence of PWD and identifying the discolored trees of disease using UAV-based high-resolution images.


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