Search results for "Gram"
showing 10 items of 9069 documents
UAV experimentation for pavement distresses detection
2022
In recent years, due to the high costs of traditional road failure detection techniques, the research has focused its attention on the use of the drone for the recognition of deterioration by experimenting with lowcost 3D detection techniques. The use of these techniques allows to carry out monitoring operations according to a structured and effective planning to guarantee the safety of users. The purpose of this paper is to verify the gradient that determines the loss of accuracy of the 3D acquisition as the flight altitude changes. in this way, the practitioner will have a handbook through which he can decide the altitude of the flight to obtain that degree of metric accuracy. The applica…
PERFORMANCE EVALUATIONS OF 3D WEB-SERVICES AND OPEN-SOURCE SOFTWARE FOR DIGITAL MODELING OF ARCHAEOLOGICAL FINDS
2016
The Structure From Motion (SFM) algorithms derived from Computer Vision community make image-based techniques a competitive and user friendly approach to obtain 3D information of real objects. These algorithms have been implemented in many 3D web-services and open-source software to develop free instruments for the reconstruction of very detailed 3D digital models. Their use is becoming very common above all in archaeological studies but their potentiality for metric application has not been tested at all. The aim of the work is to investigate the quality and the accuracy of 3D models obtained through 3D web-services and SFM open-source software. Different tests have been performed using so…
SfM Techniques Applied in Bad Lighting and Reflection Conditions: The Case of a Museum Artwork
2019
In recent years, SfM techniques have been widely used especially in the field of Cultural Heritage. Some applications, however, remain undefined in cases where the boundary conditions are not suitable for the technique. Examples of this are instances where there are poor lighting conditions and the presence of glass and reflective surfaces. This paper presents a case study where SfM is applied, using a DSLR camera (Nikon D5200), to the “Head of Hades” inside a glass theca and under a large number of light sources at different distances and of different intensities and sizes. The geometric evaluation has been made comparing the DSLR camera model against the 3D data acquired with structured l…
3D Image Based Modelling Using Google Earth Imagery for 3D Landscape Modelling
2019
In recent years SfM technique experiments have been innumerable and increasingly refined under metric profiles. The techniques rely on photographic datasets of the objects or landscapes which can require in most cases time consuming and expensive surveys. Recently however there have been increases in the available 3D data of sites worldwide on the Google Earth (GE) platform. This paper presents a unique experimentation that considers integrating readily available datasets from GE and images taken during surveys on ground level for 3D replication without the use of expensive aerial surveys. This will enable practitioners the ability to more easily create 3D models of cultural heritage signif…
Survey and Photogrammetric Restitution of Monumental Complexes: Issues and Solutions—The Case of the Manfredonic Castle of Mussomeli
2019
The latest results obtained through photogrammetric restitution enhanced by GNSS (Global Navigation Satellite System) RTK (Real-Time Kinematic) survey achieved increased levels of accuracy. These survey solutions are used to rapidly obtain a detailed model with an excellent level of accuracy (centimetric) with cheaper equipment. However, the contour conditions are not always favorable for obtaining the best results in a simple way. The work presented in this paper shows the survey and the photogrammetric restitution of the Manfredonic Castle of Mussomeli in Sicily, developed as a part of the PON NEPTIS European Project, aimed at the valorization of Cultural Heritage (CH). This case is a typ…
Vision metrology and Structure from Motion for archaeological heritage 3D reconstruction: A Case Study of various Roman mosaics
2017
<p class="Abstract">Vision metrology and computer vision can be successfully used for archaeological heritage 3D reconstruction in very high precision 3D measurement projects. Of those archaeological objects requiring very accurate measurements (&lt;1 mm), ancient mosaics comprise some of the most important. The aim of this paper is to assess the photogrammetric/computer vision approach in a vision metrology context as part of a 3D mosaics survey. In order to evaluate the optimal photogrammetric/computer vision workflow in this work, three different surveys were performed on three mosaics of different sizes and locations. Two of these are stored at the <em>Antonino Salinas&l…
Rediscovering the coastal towers of Salerno. History and representation
2023
The focus is on the ongoing developments in the field of digitisation for the preservation and conservation of Cultural Heritage. The work draws attention to the important and necessary multidisciplinary approach, which inextricably links history and new technologies in the field of survey and representation. The case study concerns the defence system of coastal towers in the province of Salerno, an area that has always been rich in history and a crossroads of peoples and civilisations. The use of new technologies in the conservation of historical and architectural heritage is in fact a fundamental step to improve the analysis, conservation and dissemination of these sites and buildings. Af…
UAV and GPR Data Integration in Glacier Geometry Reconstruction: A Case Study from Irenebreen, Svalbard
2022
Although measurements of thickness and internal structure of glaciers are substantial for the understanding of their evolution and response to climate change, detailed data about polythermal glaciers, are scarce. Here, we present the first ground-penetrating radar (GPR) measurement data of Irenebreen, and high-resolution DEM and orthomosaic, obtained from unmanned aerial vehicle (UAV) photogrammetry. A combination of GPR and UAV data allowed for the reconstruction of the glacier geometry including thermal structure. We compare different methods of GPR signal propagation speed determination and argue that a common midpoint method (CMP) should be used if possible. Our observations reveal that…
TECNOLOGIE DI RILIEVO 3D PER LA DOCUMENTAZIONE, L’INTERPRETAZIONE E LA VALORIZZAZIONE DEL PATRIMONIO ARCHEOLOGICO: IL CASO STUDIO DEL PARCO ARCHEOLOG…
2020
In recent decades, the application of geomatics technologies and methodologies to archaeological studies has led to a substantial change in onsite survey techniques and allowed an interdisciplinary approach between archaeology and digital technologies. The employment of these techniques aims to reduce the time of research and documentation, to acquire large amounts of data and to manage, in a more efficiently and quickly way, different datasets. Moreover, these new approaches provide non-invasive, flexible, low-cost methodologies to improve archaeological documentation from a quantitative and qualitative point of view. Nowadays, archaeologists can take advantage of various recording techniq…
Crowd sourcing and low cost strategies of survey for documentation and analysis of museum collections
2019
In these last years, there has been an increasing use of the Structure from Motion (SfM) techniques applied to Cultural Heritage. The accessibility of SfM software can be especially advantageous to users in non-technical fields or to those with limited resources. Thanks to SfM using, everyone can make with a digital camera a 3D model applied to an object of both Cultural Heritage, and physically Environment, and work arts, etc. One very interesting and useful application can be envisioned into museum collection digitalization. In the last years, a social experiment has been conducted involving young generation to live a social museum using their own camera to take pictures and videos. Stude…