Simple method for multiplexing channels in a Fourier optical processor

S.PALMA; J.BARBE; J.CAMPOS; CLAUDIO IEMMI

Porlamar Venezuela

Congreso; RIAO/OPTILAS 2004; 2004

Comité Territorial de Optica

  Ones of the most popular devices used into optical processors to display images are the liquid crystal light modulators (LCSLMs). Many applications in signal processing task use images with less resolution than the modern LCLMs can support. In this contribution we propose a new method based on a spatial multiplexing that uses the high resolution of the modern LCSLMs to introduce several channels in an optical correlator. The proposed method for the channel codification is based on the multirresolution analysis. Given a RGB image, before it will be displayed in the LCLMs screen, a computer decompose the image in R,G and B channels, and for each channel calculates a set of 50 %, 25 % and 12.5 % scaled replicas. Then, in place of the image, the computer send to the LCSLM screen a composed scene with the original image and its replicas. Each of the images displayed in the scene defines one different channel in the optical correlator. In order to prove the method we developed an application based on signal analysis using a bank of 16 Gabor filters, that decompose the signal in 16 frequency channels (four orientations 0º, 45º, 90º, 135º and four frequencies ¼, 1/8, 1/16, 1/32 cycles/pixel). With the proposed chanels codification, a complete set of 16 filtered R, G and B images can be obtained using only 4 cycles of the optical processor, that minds that we increased the speed of the processor by factor 4.