Search results for " reconstruction"
showing 10 items of 694 documents
Comparison of quantitative Holocene temperature reconstructions using multiple proxies from a northern boreal lake
2017
Four biotic proxies (plant macrofossils, pollen, chironomids and diatoms) are employed to quantitatively reconstruct variations in mean July air temperatures ( Tjul) at Lake Loitsana (northern Finland) during the Holocene. The aim is to evaluate the robustness and biases in these temperature reconstructions and to compare the timing of highest Tjul in the individual reconstructions. The reconstructed Tjul values are evaluated in relation to local-scale/site-specific processes associated with the Holocene lake development at Loitsana as these factors have been shown to significantly influence the fossil assemblages found in the Lake Loitsana sediments. While pollen-based temperatures follow…
High Quality Reconstruction of Dynamic Objects using 2D-3D Camera Fusion
2017
International audience; In this paper, we propose a complete pipeline for high quality reconstruction of dynamic objects using 2D-3D camera setup attached to a moving vehicle. Starting from the segmented motion trajectories of individual objects, we compute their precise motion parameters, register multiple sparse point clouds to increase the density, and develop a smooth and textured surface from the dense (but scattered) point cloud. The success of our method relies on the proposed optimization framework for accurate motion estimation between two sparse point clouds. Our formulation for fusing it closest-point and it consensus based motion estimations, respectively in the absence and pres…
A coarse to fine 3D acquisition system
2015
International audience; The 3D chain (acquisition-processing-compression) is , most of the time , sequenced into several steps. Such approaches result into an one-dense acquisition of 3D points. In large scope of applications , the first processing step consists in simplifying the data. In this paper , we propose a coarse to fine acquisition system which permits to obtain simplified data directly from the acquisition. By calculating some complementary information from 2D images , such as 3D normals , multiple homogeneous regions will be segmented and affected to a given primitive class. Contrary to other studies , the whole process is not based on a mesh. The obtained model is simplified di…
Ernesto Basile e le Esposizioni Agricole Siciliane dei primi anni del ‘900
2020
In 1891 the IV Italian National Exposition was held in Palermo, the first to have a southern city as its protagonist. The area on which the pavilions were built, obtained from the expropriation of the land belonging to the Prince of Villafranca, lent itself from the following year to accommodate the housing development and new buildings to complete the Via della Libertà, a high-bourgeois boulevard that already in 1850, by cutting the same "Firriato" of the Villafranca family, had marked the expansion towards the north of the city and seen the construction of the first buildings on its eastern front. Ernesto Basile was one of the main designers of the event and future urban creations. Althou…
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…
In assenza di intervento. Rappresentazioni digitali di restauri virtuali
2015
La simulazione della realtà attraverso le tecniche di rappresentazione digitale viene oggi in aiuto dei restauratori poiché consente loro di verificare l’impatto di un restauro ancor prima di intervenire. Ciò può contribuire a evitare interventi troppo invasivi e a contenere errate pratiche che, a volte, irrimediabilmente cancellano le tracce originali. Il saggio analizza alcune esperienze di ricerca sull’illuminazione nei modelli virtuali che sono emblematiche di un approccio possibile. Le ricostruzioni tridimensionali digitali analizzate forniscono non solo le informazioni spaziali e dimensionali ma anche gli aspetti cromatici e le caratteristiche di illuminazione di un’architettura. Lo s…
Semantic-based Technique for the Automation the 3D Reconstruction Process
2010
Pages: 191 to 198, ISBN: 978-1-61208-104-5; International audience; The reconstruction of 3D objects based on point clouds data presents a major task in many application field since it consumes time and require human interactions to yield a promising result. Robust and quick methods for complete object extraction or identification are still an ongoing research topic and suffer from the complex structure of the data, which cannot be sufficiently modeled by purely numerical strategies. Our work aims at defining a new way of automatically and intelligently processing of 3D point clouds from a 3D laser scanner. This processing is based on the combination of 3D processing technologies and Semant…
From Image to Investigation 3D Reconstruction with Perspective Restitution
2022
The memory of hundreds gone buildings is preserved by few photographic images. Perspective restitution with digital representation tools can be used today to reconstruct these buildings directly in 3D space. Digital representation has overcome many limitations that affected perspective restitution in the pre-digital era. In this paper the inner space of the church of San Michele in Trapani, destroyed at the end of the 50’, is reconstructed with the aid of three period photographic images. Some architectural elements that escaped destruction and are today located in a new church near Trapani have been surveyed with laser scanning and SfM photogrammetric techniques. Surveyed elements provided…
Managing archaeological excavations with an Archeaological Information System (SIDGEIPA)
2003
Se analizan diferentes aspectos del proceso que hemos seguido para desarrollar e implementar un software completamente nuevo para gestionar excavaciones arqueológicas. El software llamado SIDGEIPA (Sistema Distribuido para la Gestión Integrada de excavaciones arqueológicas) incluye diferentes módulos que permiten a los usuarios almacenar datos arqueológicos de diferentes fuentes (excavaciones, prospecciones, literatura científica, colecciones de museos ...) y procesarlos automáticamente para simplificar la investigación arqueológica. Técnicamente, Sidgeipa está construido en código Java, utilizando Postgres como SGBD y con las bibliotecas VTK y GEF para visualizar los datos. La arquitectura…
Localization of 2D Cameras in a Known Environment Using Direct 2D-3D Registration
2014
International audience; In this paper we propose a robust and direct 2D-to- 3D registration method for localizing 2D cameras in a known 3D environment. Although the 3D environment is known, localizing the cameras remains a challenging problem that is particularly undermined by the unknown 2D-3D correspondences, outliers, scale ambiguities and occlusions. Once the cameras are localized, the Structure-from-Motion reconstruction obtained from image correspondences is refined by means of a constrained nonlinear optimization that benefits from the knowledge of the scene. We also propose a common optimization framework for both localization and refinement steps in which projection errors in one v…