Rotationally invariant pattern recognition in a photorefractive joint transform correlator using circular harmonic filters and the wavelet transform

Hui Zhang, Colin M. Cartwright, Mei-Song Ding, Zhao-Qi Wang, Bao-Lai Liang, W. Allan Gillespie

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

A photorefractive joint transform correlator using circular harmonic filters and the wavelet transform for high discriminant and rotationally invariant pattern recognition is reported. In the experimental implementation, a photorefractive crystal, BSO, is used as the dynamic holographic medium and a bank of wavelet functions, derived from a mother Mexican-hat wavelet have been selected to achieve a band-pass operation in the Fourier domain. The zero-order and second-order circular harmonic components are used in the investigation. It is shown that, with the proper dilation factors, there is a trade-off between peak correlation intensity and signal-to-noise ratio (SNR) with the wavelet transform filters. With the second-order circular harmonic, an improvement of 63% in the SNR is achieved with only a 4% loss in the peak correlation intensity.
Original languageEnglish
Pages (from-to)383-391
Number of pages9
JournalOptics Communications
Volume195
Issue number5-6
DOIs
Publication statusPublished - 15 Aug 2001

Fingerprint

Correlators
correlators
pattern recognition
wavelet analysis
Wavelet transforms
Pattern recognition
Signal to noise ratio
Photorefractive crystals
harmonics
filters
signal to noise ratios
crystals

Cite this

Zhang, Hui ; Cartwright, Colin M. ; Ding, Mei-Song ; Wang, Zhao-Qi ; Liang, Bao-Lai ; Gillespie, W. Allan. / Rotationally invariant pattern recognition in a photorefractive joint transform correlator using circular harmonic filters and the wavelet transform. In: Optics Communications. 2001 ; Vol. 195, No. 5-6. pp. 383-391.
@article{257e28bd16e740629c36f42331b97cdf,
title = "Rotationally invariant pattern recognition in a photorefractive joint transform correlator using circular harmonic filters and the wavelet transform",
abstract = "A photorefractive joint transform correlator using circular harmonic filters and the wavelet transform for high discriminant and rotationally invariant pattern recognition is reported. In the experimental implementation, a photorefractive crystal, BSO, is used as the dynamic holographic medium and a bank of wavelet functions, derived from a mother Mexican-hat wavelet have been selected to achieve a band-pass operation in the Fourier domain. The zero-order and second-order circular harmonic components are used in the investigation. It is shown that, with the proper dilation factors, there is a trade-off between peak correlation intensity and signal-to-noise ratio (SNR) with the wavelet transform filters. With the second-order circular harmonic, an improvement of 63{\%} in the SNR is achieved with only a 4{\%} loss in the peak correlation intensity.",
author = "Hui Zhang and Cartwright, {Colin M.} and Mei-Song Ding and Zhao-Qi Wang and Bao-Lai Liang and Gillespie, {W. Allan}",
year = "2001",
month = "8",
day = "15",
doi = "10.1016/S0030-4018(01)01313-X",
language = "English",
volume = "195",
pages = "383--391",
journal = "Optics Communications",
issn = "0030-4018",
publisher = "Elsevier",
number = "5-6",

}

Rotationally invariant pattern recognition in a photorefractive joint transform correlator using circular harmonic filters and the wavelet transform. / Zhang, Hui; Cartwright, Colin M.; Ding, Mei-Song; Wang, Zhao-Qi; Liang, Bao-Lai; Gillespie, W. Allan.

In: Optics Communications, Vol. 195, No. 5-6, 15.08.2001, p. 383-391.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Rotationally invariant pattern recognition in a photorefractive joint transform correlator using circular harmonic filters and the wavelet transform

AU - Zhang, Hui

AU - Cartwright, Colin M.

AU - Ding, Mei-Song

AU - Wang, Zhao-Qi

AU - Liang, Bao-Lai

AU - Gillespie, W. Allan

PY - 2001/8/15

Y1 - 2001/8/15

N2 - A photorefractive joint transform correlator using circular harmonic filters and the wavelet transform for high discriminant and rotationally invariant pattern recognition is reported. In the experimental implementation, a photorefractive crystal, BSO, is used as the dynamic holographic medium and a bank of wavelet functions, derived from a mother Mexican-hat wavelet have been selected to achieve a band-pass operation in the Fourier domain. The zero-order and second-order circular harmonic components are used in the investigation. It is shown that, with the proper dilation factors, there is a trade-off between peak correlation intensity and signal-to-noise ratio (SNR) with the wavelet transform filters. With the second-order circular harmonic, an improvement of 63% in the SNR is achieved with only a 4% loss in the peak correlation intensity.

AB - A photorefractive joint transform correlator using circular harmonic filters and the wavelet transform for high discriminant and rotationally invariant pattern recognition is reported. In the experimental implementation, a photorefractive crystal, BSO, is used as the dynamic holographic medium and a bank of wavelet functions, derived from a mother Mexican-hat wavelet have been selected to achieve a band-pass operation in the Fourier domain. The zero-order and second-order circular harmonic components are used in the investigation. It is shown that, with the proper dilation factors, there is a trade-off between peak correlation intensity and signal-to-noise ratio (SNR) with the wavelet transform filters. With the second-order circular harmonic, an improvement of 63% in the SNR is achieved with only a 4% loss in the peak correlation intensity.

U2 - 10.1016/S0030-4018(01)01313-X

DO - 10.1016/S0030-4018(01)01313-X

M3 - Article

VL - 195

SP - 383

EP - 391

JO - Optics Communications

JF - Optics Communications

SN - 0030-4018

IS - 5-6

ER -