Search results for " image processing."
showing 10 items of 2265 documents
Implicit motor learning in discrete and continuous tasks: Toward a possible explanation of discrepant results
2009
Abstract
Vineyard leaf roughness characterization by computer vision and cloud computing technics
2010
International audience; In the context of vineyard leaf roughness analysis for precision spraying applications, this article deals with its characterization by computer vision and cloud computing techniques. The techniques merge feature extraction, linear or nonlinear dimensionality reduction techniques and several kinds of classification methods. Different combinations are processed and their performances compared in terms of classification error rate, in order to find the best association. However these combinations are hardly processed because of the lack of computing power and the prohibitive time consumption of the algorithms. To overcome these difficulties, we propose a solution: the …
Weed detection by aerial imaging: impact of soil, crop and weed spectral mixing
2015
International audience; This study aims to evaluate spectral information potential of images captured with a UAV, for site specific weed management. The image acquisition chain was modeled in order to compute the digital values of image pixels, according to the field conditions and objects lying on the ground surface projected in the pixels. The object spectra are mixed in the same pixel to estimate the impact of the spatial resolution of the image. The classification potential into crop, weed and soil classes was studied usinf simulations based on the present multispectral sensor characteristics and according to different mixing rates.
Cardiac arrhythmia induced by hypothermia in a cardiac model in vitro
2013
nouvelle version avec l'article complet; International audience; The neurological damage after cardiac arrest (CA) constitutes a big challenge of hospital discharge since years. The therapeutic hypothermia therapy (34°C-32°C) has shown its benefit to reduce cerebral oxygen demand and improve neurological outcomes after the cardiac arrest. Despite the fact that induced hypothermia after CA has been shown to increase the hospital survival rate, it can have many adverse effects, among which the cardiac arrhythmia generation represents an important part (up to 34%, according different clinical studies). Compared to studies in vivo, cardiac culture in vitro provides a better spatial resolution a…
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…