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	Provedor de dados ArchiMer (4) Autor Karoui, Imen (4) Augustin, Jean-marie (2) Boucher, Jean-marc (2) Craneguy, Philippe (2) Fablet, Ronan (2) Garreau, Pierre (2) Bertino, L. (1) Chauris, H. (1) Chauris, Hervé (1) Wackernagel, H. (1) Mais... Palavra-chave Active regions (2) Level sets (2) Angular backscattering (1) Circle detection (1) Circlet transform (1) Computer vision (1) Feature selection (1) Image processing (1) Multi-scale representation (1) Nonparametric distributions (1) Segmentation (1) Sonar images (1) Supervised and unsupervised segmentation (1) Texture (1) Texture similarity measure (1) Mais... Tipo do documento Text (4) Ano 2011 (1) 2010 (2) 2008 (1) País France (4) Idioma Inglês (4)		Ordenar por:  Relevância Autor Título Ano Registros recuperados: 4 Primeira ... 1 ... Última Multi-resolution eddy detection from ocean color and Sea Surface Temperature images ArchiMer Karoui, Imen; Chauris, Hervé; Garreau, Pierre; Craneguy, Philippe. We propose a multi resolution method for automatic detection of eddies on both simulated and satellite Sea Surface Temperature (SST) or ocean color images. Our approach consists in a curvelet based analysis of image fronts along circles with specified radius values. The main interests of the proposed method are: It is carried out on image gradient, and is thus not sensitive to the choice of binarization threshold; With the multi-resolution aspect and the anisotropic spatial support shape of curvelet elements, we can deal with no perfectly circular eddies (curvelet width) and we also take into account the image regularity to distinguish between real eddies and noise (curvelet length). We have tested the method on several modeled and satellite images in the... Tipo: Text Ano: 2010 URL: http://archimer.ifremer.fr/doc/00068/17888/15422.pdf The circlet transform: A robust tool for detecting features with circular shapes ArchiMer Chauris, H.; Karoui, Imen; Garreau, Pierre; Wackernagel, H.; Craneguy, Philippe; Bertino, L.. We present a novel method for detecting circles on digital images. This transform is called the circlet transform and can be seen as an extension of classical 1D wavelets to 2D; each basic element is a circle convolved by a 1D oscillating function. In comparison with other circle-detector methods, mainly the Hough transform, the circlet transform takes into account the finite frequency aspect of the data; a circular shape is not restricted to a circle but has a certain width. The transform operates directly on image gradient and does not need further binary segmentation. The implementation is efficient as it consists of a few fast Fourier transforms. The circlet transform is coupled with a soft-thresholding process and applied to a series of real images... Tipo: Text Palavras-chave: Circlet transform; Circle detection; Image processing; Multi-scale representation; Computer vision. Ano: 2011 URL: http://archimer.ifremer.fr/doc/00033/14451/11752.pdf Region based variational approach for the segmentation textured sonar images ArchiMer Karoui, Imen; Fablet, Ronan; Boucher, Jean-marc; Augustin, Jean-marie. We propose a new region-based segmentation of textured sonar images with respect to seafloor types. We characterize sea-floor types by a set of empirical distributions estimated on texture responses to a set of different filters and we introduce a novel similarity measure between sonar textures in this attribute space. Our similarity measure is defined as a weighted sum of Kullback-Leibler divergences between texture features. The texture similarity measure weight setting is twofold: first we weight each filter, according to its discrimination power, the computation of these weights are issued from the margin maximization criterion, Second, we add an additional weighting, evaluated as an angular distance between the incidence angles of the compared texture... Tipo: Text Palavras-chave: Level sets; Active regions; Segmentation; Angular backscattering; Feature selection; Sonar images; Texture. Ano: 2008 URL: http://archimer.ifremer.fr/doc/2008/publication-6120.pdf Variational Region-Based Segmentation Using Multiple Texture Statistics ArchiMer Karoui, Imen; Fablet, Ronan; Boucher, Jean-marc; Augustin, Jean-marie. This paper investigates variational region-level criterion for supervised and unsupervised texture-based image segmentation. The focus is given to the demonstration of the effectiveness and robustness of this region-based formulation compared to most common variational approaches. The main contributions of this global criterion are twofold. First, the proposed methods circumvent a major problem related to classical texture based segmentation approaches. Existing methods, even if they use different and various texture features, are mainly stated as the optimization of a criterion evaluating punctual pixel likelihoods or similarity measure computed within a local neighborhood. These approaches require sufficient dissimilarity between the considered texture... Tipo: Text Palavras-chave: Active regions; Level sets; Nonparametric distributions; Supervised and unsupervised segmentation; Texture similarity measure. Ano: 2010 URL: http://archimer.ifremer.fr/doc/00018/12973/9951.pdf Registros recuperados: 4 Primeira ... 1 ... Última

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