Search results for "Structure from motion"
showing 10 items of 44 documents
Structure from motion using a hybrid stereo-vision system
2015
International audience; This paper is dedicated to robotic navigation using an original hybrid-vision setup combining the advantages offered by two different types of camera. This couple of cameras is composed of one perspective camera associated with one fisheye camera. This kind of configuration , is also known under the name of foveated vision system since it is inspired by the human vision system and allows both a wide field of view and a detail front view of the scene. Here, we propose a generic and robust approach for SFM, which is compatible with a very broad spectrum of multi-camera vision systems, suitable for perspective and om-nidirectional cameras, with or without overlapping fi…
Design and Calibration of a Specialized Polydioptric Camera Rig
2017
International audience; It has been observed in the nature that all creatures have evolved highly exclusive sensory organs depending on their habitat and the form of resources availability for their survival. In this project, a novel omnidirectional camera rig, inspired from natural vision sensors, is proposed. It is exclusively designed to operate for highly specified tasks in the field of mobile robotics. Navigation problems on uneven terrains and detection of the moving objects while the robot is itself in motion are the core problems that omnidirectional systems tackle. The proposed omnidirectional system is a compact and a rigid vision system with dioptric cameras that provide a 360° f…
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…
Vision guided robotic inspection for parts in manufacturing and remanufacturing industry
2020
AbstractEnvironmental and commercial drivers are leading to a circular economy, where systems and components are routinely recycled or remanufactured. Unlike traditional manufacturing, where components typically have a high degree of tolerance, components in the remanufacturing process may have seen decades of wear, resulting in a wider variation of geometries. This makes it difficult to translate existing automation techniques to perform Non-Destructive Testing (NDT) for such components autonomously. The challenge of performing automated inspections, with off-line tool-paths developed from Computer Aided Design (CAD) models, typically arises from the fact that those paths do not have the r…
An automatic approach for rill network extraction to measure rill erosion by terrestrial and low‐cost unmanned aerial vehicle photogrammetry
2019
For an erosion event (October 2016) occurred at the Sparacia experimental area (Southern Italy), both terrestrial and low-altitude aerial surveys were carried out by consumer grade camera and quadcopter (low-cost unmanned aerial vehicle [UAV]) to measure rill erosion on two plots with steepness of 22% and 26%. Applying the structure from motion (SfM) technique, the three-dimensional digital terrain models (3D-DTMs) and the quasi three-dimensional models (2.5D-digital elevation model [DEM]) were obtained by the two surveys. Furthermore, 3D-DTM and DEM were built using the available aerial photographs (166) and adding 40 terrestrial photographs. For the first time, the convergence index was a…
Plot rill erosion measurements by close-range photogrammetry using natural events at Sparacia experimental area
2018
Recently, many investigations were carried out in order to check the applicability of both close-range and UAV (Unmanned Aerial Vehicle) photogrammetry to measure soil erosion processes. For measuring rill erosion occurring on a 22 m long and 26% sloped plot occurred on 24 October 2016 at the Sparacia experimental area, a terrestrial photographic relief and a low altitude aerial relief were carried out by no-professional quadricopter and camera. The three-dimensional (3D) DTM and the quasi-tridimensional (DEM) models were obtained. An extraction method of the rill network using DEM and convergence index was applied and a subsequent separation of rills into contributing and non-contributing …
Impiego di 3D Web-service e software open-source nel rilievo di reperti archeologici: valutazioni metriche
2013
The Structure From Motion (SFM) algorithms derived from Computer Vision community make image-based techniquesa competitive and user friendly approach to obtain 3D information of real objects. These algorithms have been implemented in many 3D web-service and open source softwareto develop free instruments for the reconstruction of very detailed 3D digital models. Their useare becoming very common above all in archaeological studies but their potentiality for metric application have 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-service and SFM open source software.Different tests have been performed using some 3D…
Investigating snowcover volumes and icings dynamics in the moraine of an Arctic catchment using UAV/ photogrammetry and LiDAR
2016
International audience; Means for assessing the contribution of the terminal moraine into the water budget of an Arctic glacier is investigated: on the one hand the terminal moraine represents a significant fraction (22%)of the catchment area of the glacier under investigation – Austre Lovenbreen, in the Brøgger peninsula, Spitsbergen – and on the other hand icings formation (or aufeis) each winter illustrates the contribution of subglacial water flow. While over the glacier, with a smooth surface readily interpolated, the winter and summer mass balances are assessed with only a few sparsely distributed stakes, such an approach is not valid with the rough topography of the glacier moraine: …
SURVEY AND VIRTUAL RECONSTRUCTION OF ANCIENT ROMAN FLOORS IN AN ARCHAEOLOGICAL CONTEXT
2019
Abstract. Despite the consistent development of approaches aimed at the virtual reconstruction of whole houses or archaeological monuments, the variety of technologies involved in virtual reconstruction procedures and the complexity of a rigorous process to provide validation models, seems to limit a univocal and shared standards adoption. For example, compared to the large number of contributions on the virtual reconstruction of whole architectures or cultural heritage sites, only a few works have proposed a rigorous workflow specific to mosaics and ancient floors and to their virtual reconstruction. The goal of this work is to present the first results on the virtual reconstruction of the…
Rainfall simulation and Structure-from-Motion photogrammetry for the analysis of soil water erosion in Mediterranean vineyards
2016
[EN] Soil water erosion is a serious problem, especially in agricultural lands.Among these, vineyards deserve attention, because they constitute for the Mediterranean areas a type of land use affected by high soil losses. A significant problem related to the study of soil water erosion in these areas consists in the lack of a standardized procedure of collecting data and reporting results, mainly due to a variability among the measurement methods applied. Given this issue and the seriousness of soil water erosion in Mediterranean vineyards, this works aims to quantify the soil losses caused by simulated rainstorms, and compare them with each other depending on two different methodologies: (…