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Weakly Supervised Learning: Application to Fish School Recognition ArchiMer
Lefort, Riwal; Fablet, Ronan; Boucher, Jean-marc.
This chapter deals with object recognition in images involving a weakly supervised classification model. In weakly supervised learning, the label information of the training dataset is provided as a prior knowledge for each class. This prior knowledge is coming from a global proportion annotation of images. In this chapter, we compare three opposed classification models in a weakly supervised classification issue: a generative model, a discriminative model and a model based on random forests. Models are first introduced and discussed, and an application to fishenes acoustics is presented. Experiments show that random forests outperform discriminative and generative models in supervised learning but random forests are not robust to high complexity class...
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Ano: 2011 URL: http://archimer.ifremer.fr/doc/00077/18782/16489.pdf
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Weakly Supervised Classification of Objects in Images Using Soft Random Forests ArchiMer
Lefort, Riwal; Fablet, Ronan; Boucher, Jean-marc.
The development of robust classification model is among the important issues in computer vision. This paper deals with weakly supervised learning that generalizes the supervised and semi-supervised learning. In weakly supervised learning training data are given as the priors of each class for each sample. We first propose a weakly supervised strategy for learning soft decision trees. Besides, the introduction of elms priors for training samples instead of hard class labels makes natural the formulation of an iterative learning procedure. We report experiments for UCI object recognition datasets. These experiments show that recognition performance close to the supervised learning can be expected using the propose framework. Besides, an application to...
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Ano: 2010 URL: http://archimer.ifremer.fr/doc/00030/14119/11371.pdf
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Angular dependence of K-distributed sonar data ArchiMer
Le Chenadec, Gilles; Boucher, Jean-marc; Lurton, Xavier.
Backscattered signal statistics are widely used for target detection and seafloor characterization. The K-distribution shows interesting properties for describing experimental backscattered intensity statistics. In addition to the fact that its probability distribution function accurately fits actual sonar data, it advantageously provides a physical interpretation linked to the backscattering phenomenon. Sonar systems usually record backscattered signals from a wide angular range across the ship's track. In this context, previous studies have shown that backscatter statistics strongly depend on the incidence angle. In this paper, we propose an extension of previous works to model the angular evolution of the K-distribution shape parameter. This evolution...
Tipo: Text Palavras-chave: K distribution; Sonar statistical analysis; Seafloor classification.
Ano: 2007 URL: http://archimer.ifremer.fr/doc/2007/publication-2599.pdf
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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
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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
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