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ABSTRACT: Fuzzy paradigm was considered from several aspects in image segmentation. For the first time, we derive a signal processing model out of an image which contains a fuzzy contour. We propose to adapt subspace-based methods of array processing which are originally dedicated to multiple incoherently distributed sources, to retrieve the orientation and spread parameters of fuzzy contours. A set of experiments performed on hand-made and real-world images shows that the proposed methods estimate accurately the expected orientation and spread parameters of fuzzy contours, and exhibit a small computational load.
Sensor Array and Multichannel Signal Processing Workshop (SAM), 2010 IEEE; 11/2010
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ABSTRACT: We consider the problem of the automatic inspection of industrial metal pieces. The purpose of the work presented in this
paper is to derive a method for defect detection. For the first time in this context we adapt level set method to distinguish
hollow regions in the metal pieces from the grinded surface. We compare this method with Canny edge enhancement and with a
thresholding method based on histogram computation. The experiments performed on two industrial images show that the proposed
method retrieves correctly fuzzy contours and is robust against noise.
10/2008: pages 655-663;
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ABSTRACT: Source localization is based on the spectral matrix algebraic properties. Propagator, and Ermolaev-Gershman (EG) noneigenvector algorithms exhibit a low computational load. Propagator is based on spectral matrix partitioning. EG algorithm obtains an approximation of noise subspace using an adjustable power parameter of the spectral matrix and choosing a threshold value. In this paper, we aim at demonstrating the usefulness of QR and LU factorizations of the spectral matrix to improve these methods. Experiments show that the modified propagator and EG algorithms based on factorized spectral matrix lead to better localization results, compared to the existing methods.
Sensor Array and Multichannel Signal Processing Workshop, 2008. SAM 2008. 5th IEEE; 08/2008
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ABSTRACT: An important cause of performance loss in source localization in underwater acoustics is that towed flexible antennas deviate from the assumed rectilinear shape. In this work, the localization of sources in presence of phase errors is studied. Cancellation of phase errors is necessary to solve the source-localization problem. A previous work led to interesting results for antennas composed of a few sensors. We propose here a novel algorithm which is adapted to the antennas composed of a large number of sensors, keeping a small computational load. Our method is based on an orthogonality property between signal and noise subspaces and a novel optimization method: the robust dividing rectangles algorithm accelerated by spline interpolation. The performances of the proposed method are illustrated by applying it to the characterization of three sources.
IEEE Signal Processing Letters 08/2007; · 1.39 Impact Factor
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ABSTRACT: Distorted curves retrieval is faced for robotic way screening, particle trajectory characterization, aerial and satellite image analysis. This image processing problem has been transposed to an array processing problem by adopting specific conventions. Some solutions for wavefront distortions canceling have already been proposed. In this paper we aim at improving an existing method for distorted curves retrieval, making use of a global optimization algorithm. We show that it is possible to combine an optimization method to an interpolation method in order to obtain a reliable and fast algorithm
Acoustics, Speech and Signal Processing, 2006. ICASSP 2006 Proceedings. 2006 IEEE International Conference on; 06/2006 · 4.63 Impact Factor
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ABSTRACT: The application of the high-resolution methods of array processing to source localisation has led to a considerable improvement in results. By considering some conventions, these methods can be applied to the characterisation of straight lines in an image. It is proposed to associate a high-resolution method with a method that generates a signal out of an image. This approach permits, in particular, to estimate the parameter 'offset', that is, the intersection with the upper side of the image of the straight lines. The proposed approach is fast and efficient when compared with the well-known method 'extension of the Hough transform'.
IEE Proceedings - Vision Image and Signal Processing 05/2006;
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ABSTRACT: The high resolution methods of array processing lead to an improvement of the results obtained for source localization. By adopting specific conventions, it is possible to employ high resolution methods to characterize straight lines in an image. In this paper, we propose an original method that leads to the estimation of the parameter "offset" of the straight lines. The proposed method is fast and effective compared to an existing method. An extension to non rectilinear contours is developed.
Acoustics, Speech, and Signal Processing, 2005. Proceedings. (ICASSP '05). IEEE International Conference on; 04/2005 · 4.63 Impact Factor
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S. Bourennane
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ABSTRACT: This paper deals with the estimation of celerity and coherence time using array of equispaced sensors for observing the ocean surface. A fast algorithm based on array processing or spatial analysis is proposed. Initially, two-antenna synthetic aperture radars (SAR) system are used in order to obtain two images of the same surface of the ocean afterwards the analysis of these images by using the signal processing or spectral analysis leads to estimate phase difference between the images and finally the mean short-term Doppler shift of the scattering from the ocean surface is estimated on pixel by pixel basis. To improve velocity and time coherence estimation the multiple antenna system is introduced in SAR system. Indeed, the use of more than two-antennas allows to develop statistical methods or multidimensional signal processing algorithms. Interesting studies, in which the blind maximum likelihood algorithms are used, have been published. Its performance is proved to be more accurate than the two-antenna SAR system based methods. The proposed algorithm is based on the second order statistics of the received data. Both the correlation and the coherence matrices are used for estimating the noise power, the spatial correlation matrix of the speckle and the coherence time of the ocean surface.
Sensor Array and Multichannel Signal Processing Workshop Proceedings, 2002; 09/2002
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ABSTRACT: The high resolution methods of array processing lead to an improvement of the results obtained for source lo-calization. By adopting specific conventions, it is pos-sible to employ high resolution methods to character-ize straight lines in an image. In this paper we pro-pose an original method that leads to the estimation of the parameter "offset" of the straight lines. The pro-posed method is fast and effective compared an exist-ing method. An extension to non rectilinear contours is developed.
