Effects of saturation on the nonlinear incoherent-erasure joint-transform correlator

Asimellis, George; Khoury, Jed; Woods, Charles L.

doi:10.1364/josaa.13.001345

Cited by 26 publications

(12 citation statements)

References 24 publications

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“…These three advantages of applying dynamic range compression on noisy signals in spectral domain lead to significant improvement of processed data relative to noise. We have already demonstrated the enhancement in both of companding optical correlators [13][14][15][16] and compression deconvolution processors [17][18][19] .…”

Section: Dynamic Range Compressionmentioning

confidence: 99%

“…The matching template filter was made from enhanced scattering centers of images' region of interest (ROI). We have also introduced a new category of companding nonlinear processors for noise reduction 12 , correlators [13][14][15][16] , and image restoration [17][18][19] based on companding coupling in nonlinear holographic media. The companding correlators showed a significant improvement on both phase and binary phase only filters in detection of signals embedded in a very high noise environment.…”

Section: Introductionmentioning

confidence: 99%

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Two-beam coupling correlation synthetic aperture radar image recognition with power-law scattering centers pre-enhancement

et al. 2008

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Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing this collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. (From -To) REPORT DATE (DD-MM-YYYY) 03-06-2008 REPORT TYPE Conference Paper DATES COVERED SPONSOR/MONITOR'S REPORT NUMBER(S) AFRL-RY-HS-TP-2008-0001 DISTRIBUTION / AVAILABILITY STATEMENTDISTRIBUTION A: APPROVED FOR PUBLIC RELEASE: DISTRIBUTION UNLIMITED. SUPPLEMENTARY NOTESThe U.S. Government is joint author of this work and has the right to use, modify, reproduce, release, perform, display, or disclose the work. Published in Proceedings of SPIE, Vol. 6973 697301-1. Cleared for Public Release by ESC/PA number: ESC-08-0010. ABSTRACTSynthetic radar image recognition is an area of interest for military applications including automatic target recognition, air traffic control, and remote sensing. Here a dynamic range compression two-beam coupling joint transform correlator for detecting synthetic aperture radar (SAR) targets is utilized. The joint input image consists of a pre-powerlaw, enhanced scattering center of the input image and a linearly synthesized power-law enhanced scattering center template. Enhancing the scattering center of both the synthetic template and the input image furnishes the conditions for achieving dynamic range compression correlation in two-beam coupling. Dynamic range compression: (a) enhances the signal to noise ratio, (b) enhances the high frequencies relative to low frequencies, and (c) converts the noise to high frequency components. This improves the correlation peak intensity to the mean of the surrounding noise significantly. Dynamic range compression correlation has already been demonstrated to outperform many optimal correlation filters in detecting signals in severe noise environments. The performance is evaluated via established metrics, such as peak-to-correlation energy (PCE), Horner efficiency and correlation peak intensity. The results showed significant improvement as the power increased. SUBJECT TERMSPattern recognition, correlation, synthetic aperture radar (SAR) ABSTRACT Synthetic radar image recognition is an area of interest for military applications including automatic target recognition, air traffic control, and remote sensing. Here a dynamic range compression two...

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Section: Dynamic Range Compressionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Two-beam coupling correlation synthetic aperture radar image recognition with power-law scattering centers pre-enhancement

et al. 2008

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“…These three effects lead to a significant signal to noise ratio improvement within the processed data. We have already demonstrated the performance of dynamic range compression in both optical correlation [14][15][16][17] and compression deconvolution [18][19][20] . In this paper we use power-law dynamic range compression in the Fourier plane.…”

Section: Radon Transfrom Inverse Sdf Filtermentioning

confidence: 99%

Power-law radon-transformed superimposed inverse filter synthetic discriminant correlator for facial recognition

et al. 2008

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Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing this collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. (From -To) 16- Mar-2008 -20-Mar-2008 REPORT DATE (DD-MM-YYYY) 20-03-2008 REPORT TYPE Conference Proceeding Paper DATES COVERED PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES)Optoelectronic Technology Branch, 80 Scott Drive, Hanscom AFB, MA 01731 *Solid State Scientific Corporation, Hollis, NH 03049 PERFORMING ORGANIZATION REPORT SPONSOR/MONITOR'S ACRONYM(S)AFRL/RYHC SPONSORING / MONITORING AGENCY NAME(S) AND ADDRESS(ES)Electromagnetics SUPPLEMENTARY NOTESThe U.S. Government is joint author of this work and has the right to use, modify, reproduce, release, perform, display or disclose the work. Published in Proceedings of SPIE, Vol. 6973 69730M-1. Clearance ESC/PA, ESC 08-0012 ABSTRACTA power-law correlation based on an inverse filter Fourier-Radon-transform synthetic discriminant function (SDF) for facial recognition is proposed. In order to avoid spectral overlap and nonlinear crosstalk, superposition of rotationally variant sets of inverse filter Fourier-transformed Radon-processed templates is used to generate the SDF. For the inverse filter, the Fourier transform of M projections (Radon Transform) from one training image is combined with (N-1) M Fourier transform of M projections taken from another N-1 training image. This synthetic SDF filter has a very high discrimination capability; however, it is not noise robust. To overcome this problem, a power-law dynamic range compression is added to the correlation process. The proposed filter has three advantages: (1) high discrimination capability as an inverse filter, (2) noise robustness due to dynamic range compression, and (3) crosstalk-free nonlinear processing. The filter performance was evaluated by established metrics, such as peak-to-correlation energy (PCE), Horner efficiency, and correlation-peak intensity. The results showed significant improvement as the power-law filter compression increased. ABSTRACT A power-law correlation based on an inverse filter Fourier-Radon-transform synthetic discriminant function (SDF) for facial recognition is proposed. In order to avoid spectral overlap and nonlinear crosstalk, superposition of rotationally variant se...

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“…2. In this configuration coherent beams 1 and 4 write a grating in a photorefractive crystal [16,17]. This grating is read out by coherent beam 2 to generate a phase conjugate beam i.e, beam 3 shown in Fig.…”

Section: Incoherent-erasure Joint Transform Correlationmentioning

confidence: 99%

“…The new design is basically a modified version of the incoherent-erasure joint transform correlator [16][17][18]. Implementing the new design by the use of the appropriate photorefractive media such as quantum wells [19][20][21] has the potential of operating the system in nanosecond time scale with high resolution.…”

Section: Introductionmentioning

confidence: 99%

<title>Fringe-adjusted nonlinear incoherent-erasure joint transform correlation</title>

Alam

Khoury²

1998

SPIE Proceedings

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A new all-optical nonlinear fringe-adjusted joint transform correlation (JTC) technique is proposed. The proposed scheme is based on incoherent-to-coherent conversion with the erasure of a four-wave mixing arrangement in a real-time photorefractive media. This technique is very fast because it generates the correlation output in one step and all intermediate processing is performed in the optical domain. Furthermore, this technique eliminates the problems due to nonlinearities associated with the square law devices and spatial light modulators used for recording the joint power spectrum. Computer simulation results show that the proposed joint transform correlator yields superior performance when compared to the alternate joint transform correlator architectures.

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Effects of saturation on the nonlinear incoherent-erasure joint-transform correlator

Cited by 26 publications

References 24 publications

Two-beam coupling correlation synthetic aperture radar image recognition with power-law scattering centers pre-enhancement

Two-beam coupling correlation synthetic aperture radar image recognition with power-law scattering centers pre-enhancement

Power-law radon-transformed superimposed inverse filter synthetic discriminant correlator for facial recognition

<title>Fringe-adjusted nonlinear incoherent-erasure joint transform correlation</title>

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