Search results for "SfM"

Multi sensor photogrammetric techniques for the documentation of the ruins of Temple G in Selinunte

2022

In the past two decades UAV have been increasingly used for the survey of wide areas. The chosen case study, the huge heap of ruins of the Temple G in Selinunte, demands a higher accuracy than that usually accepted for wide areas survey; nonetheless, the morphology of the ruins makes laser scanning survey inadequate to the purpose of the analysis and interpretation. The proposed methodology integrates SfM photogrammetry from UAV and action camera’s photos. A test on a specific area has evaluated the accuracy of photogrammetric survey through the comparison with laser scanning data.

Measurement of Water Soil Erosion at Sparacia Experimental Area (Southern Italy): A Summary of More than Twenty Years of Scientific Activity

2022

The main purpose of this article is to give a general idea of the scientific activity that was carried out starting from the 2000s on the basis of the data collected in the plots installed at the Sparacia experimental station for soil erosion measurement in Sicily, South Italy. The paper includes a presentation of the experimental site, a description of the methods and procedures for measuring soil erosion processes both available in the literature and applied at the Sparacia station (sediment sampling and water level reading in the storage tanks for total erosion measurements; profilometer, and Structure from Motion technique for rill erosion measurements), and the main results obtained in…

Low cost survey techniques aimed to the Cultural Heritage conservation.

2017

Thanks to SfM (Image Based Modeling) survey techniques, is possible to realize 3D models of every object, in a very short time and with limited economical and training resources, today. These semi-automated SfM software allow users to simply upload photos and follow a mediated workflow, without any complex inner workings of SfM and this can be especially advantageous to users in non-technical fields or to those with limited resources. Every year there is an international Event, #digitalinvasion, that involves the Italian museums and that reckons on to allow to take pictures and video to the whole museum collections. This event is present in Palermo since 2014 and the Engineering first year …

Development of a Virtual CH Path on WEB: Integration of a GIS, VR, and Other Multimedia Data

2021

Recent advances in computer science allowed people to explore new possibilities for the fruition of CH all around the world. The development of Geographic Information Systems (GIS) in the field of territorial systems and the evolution of Virtual Reality (VR) solutions opened new scenarios for the valorization of cultural goods. At the same time, recent advances in digital photogrammetry and 3D interactive navigation models on WEB-based on WebGL technologies offered new opportunities of digital fruition of CH. Considering this panorama, the presented work shows how the integration of these technologies gives a precious added value to the virtual fruition of CH. In particular, it has been con…

Hybrid foveated vision system for video surveillance and robotic navigation

2014

The primary goal of this thesis is to elaborate a binocular vision system using two different types of camera. The system studied here is composed of one omnidirectional camera coupled with a PTZ camera. This heterogeneous association of cameras having different characteristics is called a hybrid stereo-vision system. The couple composed of these two cameras combines the advantages given by both of them, that is to say a large field of view and an accurate vision of a particular Region of interest with an adjustable level of details using the zoom. In this thesis, we are presenting multiple contributions in visual tracking using omnidirectional sensors, PTZ camera self calibration, hybrid v…

Estimation de la pose d'une caméra dans un environnement connu à partir d'un recalage 2D-3D

2014

National audience; Nous proposons une méthode directe de recalage robuste 2D-3D permettant de localiser une caméra dans un environnement 3D connu. Il s'agit d'un problème rendu particulièrement difficile par l'absence de correspondances entre les points 3D du nuage et les points 2D. A cette difficulté, s'ajoute la différence d'échelle entre le nuage 3D connu et le nuage 3D reconstruit à partir d'images qui, de plus, peut contenir des points aberrants et des occultations. Notre méthode consiste en l'optimisation d'une fonctionnelle de manière itérative en deux étapes : estimation de la pose de la caméra et mise en correspondance 2D-3D. Ainsi, nous obtenons une méthode d'estimation conjointe …

Intérêt de l’utilisation de la photogrammétrie SfM (Structure from Motion) pour le suivi des processus nivo-glaciaires. Application au bassin du glac…

2015

National audience; L’Arctique est reconnu comme un ex¬cellent indicateur des évolutions clima¬tiques contemporaines : sa sensibilité aux moindres sollicitations climatiques en fait une zone d’étude idéale. L’étude des pro¬cessus et des dynamiques glaciaires revêt, dans ce contexte, un intérêt majeur afin de mieux comprendre les impacts du climat sur la récession glaciaire observée durant cette dernière décade.

Designing trehalose-conjugated peptide inhibitors for the oligomerization and toxicity of Alzheimer’s Aβ 11th Naples

2008

New metric products, movies, and 3D models from old stereopairs and their application to the in situ palaeontological site of Ambrona

2020

3D modelling tools from photographic pictures have experienced significant improvements in the last years. One of the most outstanding changes is the spread of the photogrammetric systems based on algorithms referred to as Structure from Motion (SfM) in contrast with the traditional stereoscopic pairs. Nevertheless, the availability of important collections of stereoscopic registers collected during past decades invites us to explore the possibilities for re-using these photographs in order to generate new multimedia products, especially due to the fact that many of the documented elements have been largely altered or even disappeared. This article analyses an example of application to the …

Using a small COTS UAV to quantify moraine dynamics in Arctic environments

2016

International audience; Arctic regions are known to be places where climate shift yields most visible consequences. In this context, glaciers and their environment are highly subject to global warming effects. New dynamics are observed and the behaviour of arctic systems (such as glaciers, moraines, beaches etc) changes at rates visible over yearly observations. According to recent works on climate change impacts on the cryosphere, short/violent events are recently observed and are one characteristic of these changes. As a consequence, an accelerating rate of glacial and pro-glacial activity is observed, especially at the end of each hydrological season (early fall). As an example, many pha…