Page 107 - Introduction to Information Optics

2. Signal Processing with Optics

(a)

CM-030
SCR-5,24

Fig. 2.20. (a) Input scene with a reference object, (b) Output correlation distribution.

in which we see that two cross-correlation terms are diffracted at a = 2a 0 and
a == — 2a 0, respectively.
Notice that to avoid overlapping with the zero diffraction, the separation
between the input displayed objects functions must be adequately apart; that is,

2a 0 > 2l s, (2.54)

where l s is the width of the input scene.
An example obtained from the JTC detection is provided in Fig. 2.20, in
which we see that distinctive correlation peaks are extracted from the random
background noise.