Polychromatic target identification with a color liquid-crystal-TV-based joint-transform correlator

Abstract

A real-time polychromatic target-detection technique that uses a computer-addressable color liquid-crystal- TV-based joint-transform correlator (JTC) is presented. One of the major features of the polychromatic JTC is that the spectra content of the object can be exploited. Since the liquid-crystal-TV panel is computer addressable, the JTC system can be made adaptive, by which the joint-transform power spectrum can be manipulated. Experimental demonstration of the proposed polychromatic JTC is provided, in which we show that the spatial and the spectral content of targets can be detected.

Color Pattern Recognition with Recombined Single Input Channel Joint Transform Correlator

“…The introduction of color information in pattern recognition by optical correlation is usually made by means of a multi-channel correlation technique that decomposes the source and the target color images in three red, green, and blue RGB channels. The correlation is made separately for each channel, and arithmetic or logical point-wise operations can be used to derive the final output [17][18][19]. The concept of separation into color channels led to the development of multi-channel optical color pattern-recognition systems.…”

Coded Single Input Channel for Color Pattern Recognition in Joint Transform Correlator

“…The introduction of color information in pattern recognition by the JTC is usually made by means of a multi-channel correlation technique that decomposes the source and the target color images into three red, green, and blue RGB channels. The correlation is made separately for each channel, and arithmetic or logical point-wise operations can be used to derive the final output [17][18][19][20]. The multi-channel JTC methods perform the correlation process in parallel for all the color channels that compose the image by the utilization of coherent optical correlators that are illuminated simultaneously with a few coherent sources, each having a different wavelength.…”

Single-channel polychromatic pattern recognition by the use of a joint-transform correlator

“…The inclusion of the color information in an opticalcorrelator scheme has concentrated large efforts in the last years. Several methods [3][4][5][6][7][8][9] have been devised for this purpose, most of them based on a multichannel approach.…”

“…This is achieved with a tricolor grid placed at the input plane 3,4 or by the use of the grating structure of a color liquid-crystal television ͑LCTV͒. 5 The Fourier plane consists of spatially separated spectra, each one of a different wavelength corresponding to a different channel. The correlation can be produced with a set of matched filters, one for each different spectrum, or with a JTC.…”