Page 149 - Introduction to Information Optics

134 2. Signal Processing with Optics

Sampling
phase grating
Input
image \
A

(a)

Sampling
phase grating

Input y
image
A

v
L2

(b)

Fig. 2.45. Broad spectral filtering, (a) Using a set of narrow-spectral-band filters, (b) Using a 1-D
fan-shaped broadband filter.

spectral- band filter, and h(x, y; /,„) is the spatial impulse response of
H n (p n,q n ;/-„); that is,

Thus, we see that by exploiting the spatial and the temporal coherence
content, an incoherent source processor can be made to process the informa-
tion in complex amplitude as a coherent processor. Since the output intensity
distribution is the sum of mutually incoherent image irradiances, the annoying
coherent artifact noise can be avoided.