Time filter

Source Type

Brest, France

Alfalou A.,ISEN Brest | Brosseau C.,University of Western Brittany | Alam M.S.,University of South Alabama
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2013

The purpose of this paper is to test correlation methods for pattern recognition applications. A broad overview of the main correlation architectures is first given. Many correlation data are compared with those obtained from standard pattern recognition methods. We used our simulations to predict improved decisional performance from correlation methods. More specifically, we are focused on the POF filter and composite filter family. We present an optimized composite correlation filter, called asymmetric segmented phase-only filter (ASPOF) for mobile target recognition applications. The main objective is to find a compromise between the number of references to be merged in the correlation filter and the time needed for making a decision. We suggest an all-numerical implementation of a VanderLugt (VLC) type composite filter. The aim of this all-numerical implementation is to take advantage of the benefits of the correlation methods and make the correlator easily reconfigurable for various scenarios. The use of numerical implementation of the optical Fourier transform improves the decisional performance of the correlator. Further, it renders the correlator less sensitive to the saturation phenomenon caused by the increased number of references used for fabricating the composite filter. Different tests are presented making use of the peak-to-correlation energy criterion and ROC curves. These tests confirm the validity ofour technique. Elderly fall detection and underwater mine detection are two applications which are considered for illustrating the benefits of our approach. The present work is motivated by the need for detailed discussions of the choice of the correlation architecture for these specific applications, pre-processing in the input plane and post processing in the output plane techniques for such analysis. © 2013 SPIE. Source

Rezgui W.,University of Batna | Mouss L.-H.,University of Batna | Mouss K.N.,University of Batna | Mouss M.D.,University of Batna | And 2 more authors.
International Review on Modelling and Simulations | Year: 2014

In this paper, we presented a new methodology for the mathematical modeling of the photovoltaic generator's characteristics based on known electrical laws. This proposed new methodology in this work consists of a three new algorithms, each one presents the characteristic of the cell, group of cells, module, string and generator, when one or more of its components: cells, bypass diodes and blocking diodes subjected to these types of defaults: reversed polarity, open circuit, short circuit or impedance. The three new algorithms obtained can facilitate the prediction for the prognosis or the detection for the diagnosis of these photovoltaic generator's defaults. © 2014 Praise Worthy Prize S.r.l. - All rights reserved. Source

Bouvet P.-J.,ISEN Brest | Helard M.,INSA Rennes
Annales des Telecommunications/Annals of Telecommunications | Year: 2014

In this paper, we deal with the design of a full-rate space-time block coding (STBC) scheme optimized for linear iterative decoding over fast fading multiple-input multiple-output (MIMO) channel. A general and simple coding scheme called diagonal threaded space-time (DTST) code is presented for an arbitrary number of transmit and receive antennas. Theoretical analysis shows that DTST code associated with linear iterative decoding tends towards full diversity performance while providing maximum MIMO multiplexing gain. Simulation results confirm the ability of DTST to outperform the state-of-the-art STBC and conventional spatial data multiplexing schemes under iterative processing. © 2013 Institut Mines-Télécom and Springer-Verlag France. Source

Alfalou A.,ISEN Brest | Brosseau C.,European University of Brittany | Abdallah N.,ISEN Brest | Jridi M.,ISEN Brest
Optics Express | Year: 2011

We report a new spectral multiple image fusion analysis based on the discrete cosine transform (DCT) and a specific spectral filtering method. In order to decrease the size of the multiplexed file, we suggest a procedure of compression which is based on an adapted spectral quantization. Each frequency is encoded with an optimized number of bits according its importance and its position in the DC domain. This fusion and compression scheme constitutes a first level of encryption. A supplementary level of encryption is realized by making use of biometric information. We consider several implementations of this analysis by experimenting with sequences of gray scale images. To quantify the performance of our method we calculate the MSE (mean squared error) and the PSNR (peak signal to noise ratio). Our results consistently improve performances compared to the wellknown JPEG image compression standard and provide a viable solution for simultaneous compression and encryption of multiple images. © 2011 Optical Society of America. Source

Leonard I.,ISEN Brest | Alfalou A.,ISEN Brest | Alam M.S.,University of South Alabama
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2011

In this paper, we propose a new technique for rotation invariant recognition and tracking of the face of a target person in a given scene. We propose an optimized method for face tracking based on the Fringe-adjusted JTC architecture. To validate our approach, we used the PHPID data base containing1 faces with various in-plane rotations. To enhance the robustness of the proposed method, we used a three-step optimization technique by: (1) utilizing the fringe-adjusted filter (HFAF) in the Fourier plane, (2) adding nonlinearity in the Fourier plane after applying the HFAF filter, and (3) using a new decision criterion in the correlation plane by considering the correlation peak energy and five largest peaks outside the highest correlation peak. Several tests were made to reduce the number of reference images needed for fast tracking while ensuring robust discrimination and efficient of the desired target. © 2011 SPIE. Source

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