Journal ArticleDOI
Dual nonlinear correlator based on computer controlled joint transform processor: Digital analysis and optical results
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The hybrid optoelectronic processor realizes the dual nonlinear correlation (DNC) in a set-up based on a two-step nonlinear joint transform correlator architecture with crucial influence of the dynamic range and the limited number of grey levels of the CCD camera during image acquisition in the first step.Abstract:
The hybrid optoelectronic processor, presented in this paper, realizes the dual nonlinear correlation (DNC) in a set-up based on a two-step nonlinear joint transform correlator architecture. In the first step three power spectrum distributions (input scene power spectrum, reference target power spectrum, and the joint power spectrum) necessary for the nonlinear processing are captured with a CCD camera. Nonlinear modification of the joint power spectrum, which does not have to be symmetrical in the input and reference channels, is introduced digitally. In the second step, the modified joint power spectrum is Fourier transformed optically. Numerical analysis of this processor shows a crucial influence of the dynamic range and the limited number of grey levels of the CCD camera during image acquisition in the first step, on the output signal parameters and the discrimination capability of the set-up. Optical results of recognition obtained for noise-free segmented input scenes show that the set-up ...read more
Citations
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Journal ArticleDOI
Advanced optical correlation and digital methods for pattern matching—50th anniversary of Vander Lugt matched filter
TL;DR: The paper reviews some domains that appeared as emerging fields in the last years of the 20th century and have been developed later on in the 21st century, such as three-dimensional object recognition, biometric pattern matching, optical security and hybrid optical–digital processors.
Journal ArticleDOI
Improved decryption quality and security of a joint transform correlator-based encryption system
TL;DR: It is shown that it is possible to significantly improve the quality of the decrypted image by introducing a simple nonlinear operation in the encrypted function that contains the joint power spectrum, which makes the system more resistant to chosen-plaintext attacks.
Journal ArticleDOI
Nonlinear optical security system based on a joint transform correlator in the Fresnel domain
TL;DR: The security system proposed in this paper preserves the shift-invariance property of the JTC-based encryption system in the Fourier domain, with respect to the lateral displacement of the key random mask in the decryption process.
Journal ArticleDOI
Multifactor authentication reinforces optical security
TL;DR: This is the first report on combined multiple signal encoding and simultaneous AND authentications for optical security reinforcement and a demonstration using a combination of biometric images and key codes is provided.
References
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Journal ArticleDOI
Single spatial light modulator joint transform correlator
Bahram Javidi,Joseph L. Horner +1 more
TL;DR: The performance of the single SLM joint Fourier transform correlator (JTC) is compared with that of the classical JTC in the areas of correlation peak intensity, peak- to-sidelobe ratio, signal-to-noise ratio (SNR), and correlation width and it is shown that thesingle SLM JTC outperforms the classicalJTC in all such areas.
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