Open AccessMethod of synthesized phase objects for pattern recognition: matched filtering
Author(s) -
Pavel V. Yezhov,
Alexander V. Kuzmenko,
JinTae Kim,
T. V. Smirnova
Publication year - 2012
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.20.029854
Subject(s) - computer science , optical correlator , holography , fourier transform , superposition principle , phase (matter) , matched filter , optics , pattern recognition (psychology) , artificial intelligence , noise (video) , filter (signal processing) , fast fourier transform , sensitivity (control systems) , spatial frequency , spatial light modulator , grating , signal (programming language) , computer vision , algorithm , physics , image (mathematics) , electronic engineering , quantum mechanics , programming language , engineering
To solve the pattern recognition problem, a method of synthesized phase objects is suggested. The essence of the suggested method is that synthesized phase objects are used instead of real amplitude objects. The former is object-dependent phase distributions calculated using the iterative Fourier-transform (IFT) algorithm. The method is experimentally studied with a Vander Lugt optical-digital 4F-correlator. We present the comparative analysis of recognition results using conventional and proposed methods, estimate the sensitivity of the latter to distortions of the structure of objects, and determine the applicability limits. It is demonstrated that the proposed method allows one: (а) to simplify the procedure of choice of recognition signs (criteria); (b) to obtain one-type δ-like recognition signals irrespective of the type of objects; (с) to improve signal-to-noise ratio (SNR) for correlation signals by 20 - 30 dB on average. The spatial separation of the Fourier-spectra of objects and optical noises of the correlator by means of the superposition of the phase grating on recognition objects at the recording of holographic filters and at the matched filtering has additionally improved SNR (>10 dB) for correlation signals. To introduce recognition objects in the correlator, we use a SLM LC-R 2500 device. Matched filters are recorded on a self-developing photopolymer.