Synthèse d'un corrélateur optimisé : Application à la reconnaissance des lettres
Résumé
This article presents an experimental study of optical multichannel Vander lugt based on the use of a Binary Phase Only Filter (BPOF) correlators. Several solutions have been are proposed. The solution we chose was the best suited to the design and the construction of a multichannel compact and reconfigurable optical correlator (multicorrelator). The important increase in the processing capacity was made possible thanks to the design of a suitable filter (the segmented composite filter). At the beginning, our study was oriented towards segmented filtering architectures, where the reconfiguration is done in the Fourier plane. Various references are superimposed in the Fourier plane with a different carrier for each. However this creates a saturation problem in the Fourier plane, which is worsened because a binarisation of the plane is also required. In order to optimize the use of the Fourier plane, we propose an optimisation of the segmented filter. This optimisation is based on an optimal use of the band-width space product in the correlator. This filter allowed the increase the number of correlations per second, the installation of sophisticated processes (the decision is made on several peaks simultaneously and not only by one pick). And finally it increases in a very significant way, the robustness of the correlator (phenomenon of local saturation in the Fourier plane).
Mots clés
Signal Processing
Image Processing
Opto-electronic
Encoding/Decoding
Compression
Decompression
encryption
Independent Components Analyses (ICA)
Optical correlation
recognition forms
Information Processing
Diffractive optics
Digital Holography
Fourier transform
polarized light
Composite filter
POF
VLC
JTC