Search results for "TRACK"
showing 10 items of 975 documents
Asserting the Precise Position of 3D and Multispectral Acquisition Systems for Multisensor Registration Applied to Cultural Heritage Analysis
2012
International audience; We present a novel method to register multispectral acquisitions on a 3D model. The method is based on the external tracking of the acquisition systems using close-range photogrammetric techniques: multiple calibrated cameras simultaneously observe the successive acquisition systems in use. The views from these cameras are used to precisely determine the position of each acquisition system. All datasets can then be projected in the same coordinate system. The registration is thus independent from the quality and content of the data. This method is well suited to the study of cultural heritage or any other application where we do not wish to place targets on the objec…
Registration of 3D and Multispectral Data for the Study of Cultural Heritage Surfaces
2013
International audience; We present a technique for the multi-sensor registration of featureless datasets based on the photogrammetric tracking of the acquisition systems in use. This method is developed for the in situ study of cultural heritage objects and is tested by digitizing a small canvas successively with a 3D digitization system and a multispectral camera while simultaneously tracking the acquisition systems with four cameras and using a cubic target frame with a side length of 500 mm. The achieved tracking accuracy is better than 0.03 mm spatially and 0.150 mrad angularly. This allows us to seamlessly register the 3D acquisitions and to project the multispectral acquisitions on th…
Tracking in Presence of Total Occlusion and Size Variation using Mean Shift and Kalman Filter
2011
International audience; The classical mean shift algorithm for tracking in perfectly arranged conditions constitutes a good object tracking method. However, in the real environment it presents some limitations, especially under the presence of noise, objects with varying size, or occlusions. In order to deal with these problems, this paper proposes a reliable object tracking algorithm using mean shift and the Kalman filter, which was added to the traditional algorithm as a predictor when no reliable model of the object being tracked is found. Experimental work demonstrates that the proposed mean shift Kalman filter algorithm improves the tracking performance of the classical algorithms in c…
Hand Gestures Recognition and Tracking
2013
In this project we develop a system that uses low cost web cameras to recognise gestures and track 2D orientations of the hand. This report is organized as such. First in section 2 we introduce various methods we undertook for hand detection. This is the most important step in hand gesture recognition. Results of various skin detection algorithms are discussed in length. This is followed by region extraction step (section 3). In this section approaches like contours and convex hull to extract region of interest which is hand are discussed. In section 4 a method is describe to recognize the open hand gesture. Two additional gestures of palm and fist are implemented using Haar-like features. …
Using Visual Saliency for Object Tracking with Particle Filters
2010
International audience; This paper presents a robust tracking method based on the integration of visual saliency information into the particle filter framework. While particle filter has been successfully used for tracking non-rigid objects, it shows poor performances in the presence of large illumination variation, occlusions and when the target object and background have similar color distributions. We show that considering saliency information significantly improves the performance of particle filter based tracking. In particular, the proposed method is robust against occlusion and large illumination variation while requiring a reduced number of particles. Experimental results demonstrate th…
Towards visual urban scene understanding for autonomous vehicle path tracking using GPS positioning data.
2019
This PhD thesis focuses on developing a path tracking approach based on visual perception and localization in urban environments. The proposed approach comprises two systems. The first one concerns environment perception. This task is carried out using deep learning techniques to automatically extract 2D visual features and use them to learn in order to distinguish the different objects in the driving scenarios. Three deep learning techniques are adopted: semantic segmentation to assign each image pixel to a class, instance segmentation to identify separated instances of the same class and, image classification to further recognize the specific labels of the instances. Here our system segme…
Radial electron fluence around ion tracks as a new physical parameter for the detection threshold of PADC using Geant4-DNA toolkit
2018
International audience; The detection threshold of poly(allyl dyglycol carbonate), PADC, for C ions is determined as 55 eV/nm in stopping power, which is significantly higher than that for proton and He ions. The stopping power is not a universal parameter for expressing the detection threshold of PADC. A new physical parameter of Radial Electron Fluence around Ion Tracks, REFIT, is proposed to describe the detection threshold of PADC. It is defined as the number density of electrons passing through the surface of a cylinder of a certain radius that is co-axial with the trajectory. Furthermore, preliminary calculations are presently being performed using the Monte Carlo simulation code of G…
A numerical study of tropical cross-tropopause transport by convective overshoots
2007
Abstract. Observations obtained during the Tropical Convection, Cirrus and Nitrogen Oxides (TROCCINOX) golden day have revealed the presence of ice particles up to 410 K (18.2 km) 2 km above the local tropopause. The case was investigated using a three-dimensional quadruply nested non-hydrostatic simulation and Meteosat Second Generation (MSG) observations. The simulation reproduced the measurements along the flight track fairly well. A reasonable agreement with MSG observations was also achieved: the 10.8-μm brightness temperature (BT) minimum of 187 K was reproduced (a value 6 K colder than the environmental cold-point temperature) as was the positive BT difference between the 6.2- and 10…
Les interfaces à traces de pas de théropodes du Plateau des Causses (Sud de la France) : déterminations palichnologiques et interprétations paléoenvi…
2012
De nombreuses empreintes ont été découvertes depuis le début des années 2000 dans le Bathonien des Grands Causses, dans les vallées de la Jonte et de la Dourbie, autour de Meyrueis (48) et de Nant (12).Ces traces ont été identifiées par Sciau et al. (2006) comme étant des ichnites d’origine dinosaurienne. Les auteurs ont pu distinguer des traces tridactyles et d’autres de formes ovoïdes. Ils ont attribué la formation des premières à des théropodes et des autres à des sauropodes. Cependant, un doute subsistait quant à leur origine réelle, ainsi que leur détermination ichnologique qui restait à faire.Notre travail consiste en un relevé et des mesures des traces tridactyles et ovoïdes, supposé…
ENGAGED: System design of direct seedings under permanent cover crop without glyphosate
2022
Direct seeding under permanent cover crop (SDCV) corresponds to sow a crop in a multiyear vegetal cover crop(often clover) without soil perturbation. It is an emblematic technique of Conservation Agriculture whose agronomicand environmental interests are multiple because of the special attention paid to soils. However, the issue of weedcontrol and permanent cover crop control is central to SDCV culture systems. The use of non-selective herbicide suchas glyphosate is the most common technical lever for weed and cover crop management. Glyphosate is in the hotseat since the President of France announced its banning from 2023. It becomes necessary to find alternatives for thesustainability of t…