Search results for "Signal"
showing 10 items of 6924 documents
Remaillage semi-régulier pour les maillages surfaciques triangulaires : un état de l'art
2010
National audience; Les maillages surfaciques triangulaires sont désormais couramment utilisés pour modéliser des formes tridimensionnelles. Beaucoup de ces modèles géométriques sont obtenus à partir de techniques de numérisation scanner ou de représentations implicites (isosurfaces). Ainsi la géométrie de ces maillages est souvent très dense (sur-échantillonnage) et leur connectivité arbitraire (irrégularité du voisinage des sommets). Il est alors souvent nécessaire de les remailler afin de réduire leur complexité (simplification), améliorer la qualité des triangles produits, optimiser l'échantillonnage de la géométrie ou encore rendre la connectivité la plus régulière possible. Concernant …
Imagerie polarimétrique : principes et applications.
2016
National audience
Human interaction recognition based on the co-occurence of visual words
2014
International audience; This paper describes a novel methodology for automated recognition of high-level activities. A key aspect of our framework relies on the concept of co-occurring visual words for describing interactions between several persons. Motivated by the numerous success of human activity recognition methods using bag-of-words, this paradigm is extended. A 3-D XYT spatio-temporal volume is generated for each interacting person and a set of visual words is extracted to represent his activity. The interaction is then represented by the frequency of co-occurring visual words between persons. For our experiments, we used the UT-interaction dataset which contains several complex hum…
Some optical methods for cutaneous diagnostic help - Focus on multispectral imaging
2010
International audience; Some optical methods for cutaneous diagnostic help - Focus on multispectral imaging
Blind source separation of skin chromophores on a hyperspectral cube
2010
International audience; Background/Purpose The ASCLEPIOS system developed by the M2D+ team of the Le2i laboratory (Université de Bourgogne, France) allows determination of a skin reflectance spectrum over the visible wavelength range in each pixel of a 2D image, thereby generating a hyperspectral (3D) cube. Reflectance spectra mainly result from the reflectance of two skin chromophores, epidermal melanin and dermal haemoglobin. A source separation method was applied on the mixed reflectance spectra, resulting in two component spectra for melanin and haemoglobin, respectively. We also obtained through this process quantification of each chromophore in each pixel of a 2D skin image. The accur…
A smart camera for High Dynamic Range imaging
2013
International audience; A camera or a video camera is able to capture only a part of a high dynamic range scene information. The same scene can be almost totally perceived by the human visual system. This is true especially for real scenes where the difference in light intensity between the dark areas and bright areas is high. The imaging technique which can overcome this problem is called HDR (High Dynamic Range). It produces images from a set of multiple LDR images (Low Dynamic Range), captured with different exposure times. This technique appears as one of the most appropriate and a cheap solution to enhance the dynamic range of captured environments. We developed an FPGA-based smart cam…
Nouvelle tomographie Compton
2009
International audience
A classification approach to prostate cancer localization in 3T Multi-Parametric MRI
2016
International audience; Multiparametric-magnetic resonance imaging (mp-MRI) has demonstrated, in many studies, its potential in prostate cancer detection and analysis. We propose a supervised classification approach based on mp-MRI data base of 20 patients, in order to localize prostate cancer and to achieve a cartographic representation of the prostate voxels based on classification results. Proposed method provides a computer aided detection (CAD) software for prostatic cancer. For that, we have extracted varied features providing functional, anatomical and metabolic information helping the classifier to distinguish between three different classes ("Healthy", "Benign" and "Pathologic"). W…
A comparative study of noise effects in a FitzHugh-Nagumo circuit
2014
International audience; This paper focuses on the behaviour of a nonlinear FitzHugh-Nagumo circuit in the stochastic case that is in presence of noise and without deterministic driving. When the circuit is tuned below the Andronov-Hopf bifurcation, classical coherence res- onance signature is revealed. We compare the stochastic response of the system when the noise acts on two different parameters of the system. It is experimentally shown that an enhancement of the systems response can be achieved when the noise is directly added into the nonlinearity.
CDnet 2014: An Expanded Change Detection Benchmark Dataset
2014
International audience; Change detection is one of the most important low-level tasks in video analytics. In 2012, we introduced the changedetection.net (CDnet) benchmark, a video dataset devoted to the evalaution of change and motion detection approaches. Here, we present the latest release of the CDnet dataset, which includes 22 additional videos (~70,000 pixel-wise annotated frames) spanning 5 new categories that incorporate challenges encountered in many surveillance settings. We describe these categories in detail and provide an overview of the results of more than a dozen methods submitted to the IEEE Change Detection Workshop 2014. We highlight strengths and weaknesses of these metho…