Microscope Image Processing

three panels, the cosine is undersampled, and, though a cosine is reconstructed,

it has the wrong frequency. Aliasing reduces the frequency of sinusoidal com-

ponents in an image. This can be quite troublesome and should be avoided by

maintaining Dx < 1=2f

c

.

We mentioned in Chapter 2 that the OTF of a microscope objective lens

(Eq. 2.12) goes to zero for all frequencies above the optical cutoff frequency

f

c

¼ l= 2NA (Eq. 2.14). Thus the optics provide a built-in antialiasing filter, and

we can be content simply to design for Dx < 1=2f

c

, at least as far as aliasing is

concerned. However, since we cannot interpolate with the sinc function, as

contemplated ...