# Corrélation optique optimale et application aux architectures cohérentes et incohérentes

Abstract : Correlation algorithms, or more generally global filtering, have recently known important advances, and provide solutions to difficult problems in pattern recognition. However, these algorithms are not usually suited to an optical correlator without modification since they do not consider the limitations that are imposed by the devices used for image display, i.e. spatial light modulators.

We propose an optimization method for correlation filters that is suited to optical architectures. This method is based on a multicriteria optimization, performed under constraint of optical implementation.
We illustrate the performances of filters obtained in this way for the pupil synthesis and joint Fourier transform coherent correlation architectures, and also for the shadow-casting incoherent correlation architecture.

Though pupil synthetis and joint Fourier transform coherent correlation architectures have been the object of many studies these last years, the shadow-casting incoherent correlation architecture has attracted less attention.
Some authors have judged its performances insufficient compared to that of coherent architectures. A large amount of our work has therefore been devoted to a re-establishment'' of the reputation of this architecture in the light of the new devices.

We present a detailed analysis of shadow-casting incoherent optical correlation. We show how to achieve trade-offs between the antagonistic effects that are due to diffraction and photometric non-uniformities. We apply our multicriteria optimization method experimentally following a bipolar scheme. These bipolar filters allow us to obtain unprecedented performances in incoherent optical correlation.
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https://tel.archives-ouvertes.fr/tel-00143607
Contributor : Vincent Laude <>
Submitted on : Thursday, April 26, 2007 - 11:45:19 AM
Last modification on : Thursday, November 12, 2020 - 6:36:12 PM
Long-term archiving on: : Tuesday, April 6, 2010 - 11:27:48 PM

### Identifiers

• HAL Id : tel-00143607, version 1

### Citation

Vincent Laude. Corrélation optique optimale et application aux architectures cohérentes et incohérentes. Traitement du signal et de l'image [eess.SP]. Université Paris Sud - Paris XI, 1994. Français. ⟨tel-00143607⟩

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