# Tag Info

### Is there any practical application for performing a double Fourier transform? ...or an inverse Fourier transform on a time-domain input?

No, taking the Fourier transform twice is equivalent to time inversion (or inversion of whatever dimension you're in). You just get $x(-t)$ times a constant which depends on the type of scaling you ...
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### Is there any practical application for performing a double Fourier transform? ...or an inverse Fourier transform on a time-domain input?

Whilst taking the Fourier transform directly twice in a row just gives you a trivial time-inversion that would be much cheaper to implement without FT, there is useful stuff that can be done by taking ...
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Accepted

### Is there any practical application for performing a double Fourier transform? ...or an inverse Fourier transform on a time-domain input?

"Is there any practical application?" Definitely yes, at least to check code, and bound errors. Especially for huge data or a large number of iterations "In theory, theory and practice ...
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### How to build a phase shifter with arbitrary phase shift

Nice question! It uses one of my favorite trig identities (which can also be used to show that quadrature modulation is actually simultaneous amplitude and phase modulation). The impulse response of ...
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### Is there any practical application for performing a double Fourier transform? ...or an inverse Fourier transform on a time-domain input?

2D Fourier transform (2D DFT) is used in image processing since an image can be seen as a 2D signal. E.g. for a grayscale image $I$, $I(x,y)=z$, that means that at the coordinates $x$ and $y$ the ...
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### Can humans hear Hilbert transform in audio?

Can humans hear Hilbert transform in audio? Generally no. The human auditory system is fairly insensitive to monaural phase shifts. "Monaural" means "same phase shift for both ears&...
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### What information does the Hilbert transform give?

If the OP is interested in what is the practical purpose of the Hilbert Transform, the rest of this post applies. Similar to the Fourier, Laplace, and Z transforms, the Hilbert Transform can be used ...
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### Hilbert Transform in C provides possibly strange results

I am not a signal processing expert, but I have made it a good practice not to mix concepts. There is something called the Hilbert Transform, and there is an analytic signal. Here is what I do to ...
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### Not able to reach minimum phase using Hilbert transform

More taps. You don't have anywhere near enough taps for a filter that steep. Start large with 8192 or so cut to desired accuracy, if needed Due to the low number of tabs you are seeing the effect of "...
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Accepted

TLDR: if the time variable $t$, and its dual variable ($f$, $\tau$) in the expression of the bivariate kernel have the same homogeneity, (I believe that) you can call it a time-domain ...
To be clear, the Hilbert Transform in MATLAB does not actually return the Hilbert Transform, but returns the Analytic Signal given as: $$x_a(t) = x(t) + j \hat x(t)$$ Where it is the imaginary ...