Online pattern recognition in noisy background by means of wavelet coefficients thresholding

When a scene contaminated with noise has to be recognized by using an optical correlator, the output plane may be strongly affected by noise, yielding mistaken results. Different strategies have been developed to overcome this problem. In this paper we present a method that applies the thresholding...

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Detalles Bibliográficos
Autores principales: Mazzaferri, Javier Esteban, Ledesma, Silvia Adriana
Publicado: 2005
Materias:
Denoising
Optical image processing
Pattern recognition
Wavelets
Computer simulation
Image processing
Optical correlation
Optical filters
Optical resolving power
Signal to noise ratio
Gabor decomposition
Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_14644258_v7_n7_p296_Mazzaferri
http://hdl.handle.net/20.500.12110/paper_14644258_v7_n7_p296_Mazzaferri
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id paper:paper_14644258_v7_n7_p296_Mazzaferri
record_format dspace
spelling paper:paper_14644258_v7_n7_p296_Mazzaferri2023-06-08T16:16:47Z Online pattern recognition in noisy background by means of wavelet coefficients thresholding Mazzaferri, Javier Esteban Ledesma, Silvia Adriana Denoising Optical image processing Pattern recognition Wavelets Computer simulation Image processing Optical correlation Optical filters Optical resolving power Signal to noise ratio Denoising Gabor decomposition Optical image processing Wavelets Pattern recognition When a scene contaminated with noise has to be recognized by using an optical correlator, the output plane may be strongly affected by noise, yielding mistaken results. Different strategies have been developed to overcome this problem. In this paper we present a method that applies the thresholding of the wavelet coefficients to perform recognition tasks with scenes contaminated with additive noise. The method is implemented by using a Vander Lugt correlator architecture operating with liquid crystal displays. A unique filter is designed to accomplish the recognition and the denoising processes in a simultaneous way. The function to be recognized is decomposed into sub-bands based on the Gabor decomposition, in the frequency plane. The hard thresholding operation is performed and the threshold is generated with accurate support functions in the filter plane. The criterion for the threshold selection is chosen to optimize the signal-to-noise ratio in the output plane. As examples, numerical simulations and experimental results for the correlation plane are shown. We also compare some quality parameters with classical filters. © 2005 IOP Publishing Ltd. Fil:Mazzaferri, J. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Ledesma, S. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2005 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_14644258_v7_n7_p296_Mazzaferri http://hdl.handle.net/20.500.12110/paper_14644258_v7_n7_p296_Mazzaferri
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Denoising
Optical image processing
Pattern recognition
Wavelets
Computer simulation
Image processing
Optical correlation
Optical filters
Optical resolving power
Signal to noise ratio
Denoising
Gabor decomposition
Optical image processing
Wavelets
Pattern recognition
spellingShingle Denoising
Optical image processing
Pattern recognition
Wavelets
Computer simulation
Image processing
Optical correlation
Optical filters
Optical resolving power
Signal to noise ratio
Denoising
Gabor decomposition
Optical image processing
Wavelets
Pattern recognition
Mazzaferri, Javier Esteban
Ledesma, Silvia Adriana
Online pattern recognition in noisy background by means of wavelet coefficients thresholding
topic_facet Denoising
Optical image processing
Pattern recognition
Wavelets
Computer simulation
Image processing
Optical correlation
Optical filters
Optical resolving power
Signal to noise ratio
Denoising
Gabor decomposition
Optical image processing
Wavelets
Pattern recognition
description When a scene contaminated with noise has to be recognized by using an optical correlator, the output plane may be strongly affected by noise, yielding mistaken results. Different strategies have been developed to overcome this problem. In this paper we present a method that applies the thresholding of the wavelet coefficients to perform recognition tasks with scenes contaminated with additive noise. The method is implemented by using a Vander Lugt correlator architecture operating with liquid crystal displays. A unique filter is designed to accomplish the recognition and the denoising processes in a simultaneous way. The function to be recognized is decomposed into sub-bands based on the Gabor decomposition, in the frequency plane. The hard thresholding operation is performed and the threshold is generated with accurate support functions in the filter plane. The criterion for the threshold selection is chosen to optimize the signal-to-noise ratio in the output plane. As examples, numerical simulations and experimental results for the correlation plane are shown. We also compare some quality parameters with classical filters. © 2005 IOP Publishing Ltd.
author Mazzaferri, Javier Esteban
Ledesma, Silvia Adriana
author_facet Mazzaferri, Javier Esteban
Ledesma, Silvia Adriana
author_sort Mazzaferri, Javier Esteban
title Online pattern recognition in noisy background by means of wavelet coefficients thresholding
title_short Online pattern recognition in noisy background by means of wavelet coefficients thresholding
title_full Online pattern recognition in noisy background by means of wavelet coefficients thresholding
title_fullStr Online pattern recognition in noisy background by means of wavelet coefficients thresholding
title_full_unstemmed Online pattern recognition in noisy background by means of wavelet coefficients thresholding
title_sort online pattern recognition in noisy background by means of wavelet coefficients thresholding
publishDate 2005
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_14644258_v7_n7_p296_Mazzaferri
http://hdl.handle.net/20.500.12110/paper_14644258_v7_n7_p296_Mazzaferri
work_keys_str_mv AT mazzaferrijavieresteban onlinepatternrecognitioninnoisybackgroundbymeansofwaveletcoefficientsthresholding
AT ledesmasilviaadriana onlinepatternrecognitioninnoisybackgroundbymeansofwaveletcoefficientsthresholding
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