
318 ◾ Erwin Hack
described in Chapter 1 of this book. Let the fringe signal including a car-
rier frequency be written as
Γ
() () () ()cos( () ),SISS
B
xxxx xfx
(9.57)
where f is a frequency vector adding a linear carrier to the phase ϕ, and x
is short for (x,y).
e Fourier transform of this fringe pattern is
=+ +
Γ
φ+⋅
Γ
−φ +⋅
F[ ()]F[()] F[ () ]F ()
1
2
(())
1
2
((
SS Se Se
B
xx
xf
fx
(9.58)
e rst term, which describes the background signal, is found
in the center of the Fourier plane around low frequencies. Figure9.5
shows a test fringe pattern with a carrier in the y-direction of around
96 fringes across the image. e Fourier tran ...