Search results for "Pattern Recognition"

Estimation de mouvement d'un système stéréoscopique hybride à partir des droites

2010

We present a motion estimation approach for hybrid stereo rigs using line images. The proposed method can be applied to a hybrid system built up from any single view point (SVP) cameras such as perspective, central catadioptric and fisheye cameras. Such configuration combines advantageous characteristics of different types of cameras. Images captured by SVP imaging devices may be mapped to spherical images using the unified projection model. It is possible to recover the camera orientations using vanishing points of parallel line sets. We then estimate the translations from known rotations and line images on the spheres. The algorithm has been validated on simulated data and real images tak…

On Keyframe Positioning for Pose Graphs Applied to Visual SLAM

2013

International audience; In this work, a new method is introduced for localization and keyframe identification to solve a Simultaneous Localization and Mapping (SLAM) problem. The proposed approach is based on a dense spherical acquisition system that synthesizes spherical intensity and depth images at arbitrary locations. The images are related by a graph of 6 degrees-of-freedom (DOF) poses which are estimated through spherical registration. A direct image-based method is provided to estimate pose by using both depth and color information simultaneously. A new keyframe identification method is proposed to build the map of the environment by using the covariance matrix between raletive 6 DOF…

Performance evaluation of Wireless Sensor Networks based on ZigBee technology in smart home

2013

International audience; Wireless Sensor Networks (WSNs) has diverse application domains such as smart home, smart care, industrial, etc. In this paper, we present a WSN system based on the ZigBee technology (IEEE 802.15.4) in Smart Home. To have a good sensor networks communication implanted in a smart home, studies of operating performance on this network is important. In this work, we investigate the performance of our ZigBee sensor networks. The study of performance is based on measurements of the Received Signal Strength Indicator (RSSI) in different parts of the Home. We will also discuss the impact of electromagnetic noise on the communication performance of a ZigBee Sensor Network in…

Stratified Autocalibration of Cameras with Euclidean Image Plane

2020

International audience; This paper tackles the problem of stratified autocalibration of a moving camera with Euclidean image plane (i.e. zero skew and unit aspect ratio) and constant intrinsic parameters. We show that with these assumptions, in addition to the polynomial derived from the so-called modulus constraint, each image pair provides a new quartic polynomial in the unknown plane at infinity. For three or more images, the plane at infinity estimation is stated as a constrained polynomial optimization problem that can efficiently be solved using Lasserre's hierarchy of semidefinite relaxations. The calibration parameters and thus a metric reconstruction are subsequently obtained by so…

The Large Area Detector of LOFT: the Large Observatory for X-ray Timing

2014

LOFT (Large Observatory for X-ray Timing) is one of the five candidates that were considered by ESA as an M3 mission (with launch in 2022-2024) and has been studied during an extensive assessment phase. It is specifically designed to perform fast X-ray timing and probe the status of the matter near black holes and neutron stars. Its pointed instrument is the Large Area Detector (LAD), a 10 m 2 -class instrument operating in the 2-30keV range, which holds the capability to revolutionise studies of variability from X-ray sources on the millisecond time scales. The LAD instrument has now completed the assessment phase but was not down-selected for launch. However, during the assessment, most o…

LOFT: the Large Observatory For X-ray Timing

2012

The LOFT mission concept is one of four candidates selected by ESA for the M3 launch opportunity as Medium Size missions of the Cosmic Vision programme. The launch window is currently planned for between 2022 and 2024. LOFT is designed to exploit the diagnostics of rapid X-ray flux and spectral variability that directly probe the motion of matter down to distances very close to black holes and neutron stars, as well as the physical state of ultra-dense matter. These primary science goals will be addressed by a payload composed of a Large Area Detector (LAD) and a Wide Field Monitor (WFM). The LAD is a collimated (<1 degree field of view) experiment operating in the energy range 2-50 keV,…

Identification of the VvFLS2 grapevine flagellin receptor by a functional genomics strategy

2013

National audience; Grapevine (Vitis vinifera) is a crop of high agronomic interest subject to many destructive diseases. Pattern recognition receptors (PRRs) mediate detection of potential pathogens via the perception of pathogen associated molecular patterns (PAMPs), which is important for plant disease resistance. A well studied PRR is the Arabidopsis leucine-rich repeat receptor kinase FLS2 that recognizes bacterial flagellin (or its minimal motif flg22). Flagellin perception plays an important role in restricting bacterial invasion into plant leaves. Until now, functional FLS2 orthologues have been characterized in Nicotiana benthamiana, rice and tomato. Despite its economical importanc…

Comment stimuler l’immunité de la vigne avec des éliciteurs

2013

Improved Estimation of Cardiac Function Parameters Using a Combination of Independent Automated Segmentation Results in Cardiovascular Magnetic Reson…

2015

International audience; This work aimed at combining different segmentation approaches to produce a robust and accurate segmentation result. Three to five segmentation results of the left ventricle were combined using the STAPLE algorithm and the reliability of the resulting segmentation was evaluated in comparison with the result of each individual segmentation method. This comparison was performed using a supervised approach based on a reference method. Then, we used an unsupervised statistical evaluation, the extended Regression Without Truth (eRWT) that ranks different methods according to their accuracy in estimating a specific bio-marker in a population. The segmentation accuracy was …

Terahertz Biomedical Imaging: From Multivariate Analysis and Detection to Material Parameter Extraction

2017

Terahertz imaging is an interesting route for biomedical analysis. In particular, cancer imaging is a subject of study for different teams [1,2]. A work is done in Bordeaux in partnership with a hospital to do terahertz analysis of breast tissue. This work is done in reflection with time domain imaging setup with fresh samples. The aim is to accurately assess tumor margins and which could in the future allow a quick validation of the precision of the surgical procedure and know if new surgery should be performed. We have presented in a previous paper [3] the use of automatic methods of image generation with different parameters [4] in order to explore the different contrasts that exist in t…