So, Hann filter is:
H(k)=(1+cos(2*pi*k/W))/2 , W=2*kmax
and based on this, the inverse Fourier of Hann filter is supposed to be:
h(x) = 1/2delt(x) + 1/4(delta(x-1)+delta(x+1))
where delta(.)
is the Dirac Delta function. So, if Hk
and hx
denotes H(k)
and h(x)
, respectively:
n = 128;
Hk = hann(n,'symmetric')';
hx = ifft(ifftshift(Hk));
I tested hx
and Hk
on a sample 1D signal here, and the result seems to be working as I expected. However, hx
does not look as what I expected which is the sum of 3 delta Dirac functions. What is missing in my code?