Questions tagged [zero-padding]
Zero padding consists of extending a signal (or spectrum) with zeros to extend its time (or frequency band) limits.
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Why should I zero-pad a signal before taking the Fourier transform?
In an answer to a previous question, it was stated that one should
zero-pad the input signals (add zeros to the end so that at least half of the wave is "blank")
What's the reason for this?
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1answer
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What happens when N increases in N-point DFT [duplicate]
I am curious about DFT, and I wrote a simple MATLAB code to test what happens when $N$ increases. I took a rectangular signal with length $L=15$, an then found th DFT of 16, 32 and 64 points. I looked ...
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Frequency-domain zero padding - special treatment of X[N/2]
Suppose we wish to interpolate a periodic signal with an even number of samples (e.g. N=8) by zero-padding in the frequency domain.
Let the DFT X=[A,B,C,D,E,F,G,H]
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2answers
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Why do we say that “zero-padding doesn't really increase frequency resolution”
Here is a sinusoid of frequency f = 236.4 Hz (it is 10 milliseconds long; it has N=441 points at sampling rate ...
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2answers
613 views
What proportion of a padded FFT should be actual values
For a given signal, I've been told that you can pad the vector with $0$s at the end to get a larger DFT, and as a result get more precision in frequency bins.
What are the limits to this approach?
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3answers
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How does zero-padding affect the magnitude of the DFT?
Let's simulate sinusoids of two frequencies using the following Matlab code:
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3answers
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Zero Padding in FFT
whats is the effect of pading zeroes to a sequence in FFT?
for eg: x[n]=[2 3 4 5] corresponds to X[K]=[14 -2+2i -2 -2-2i]
while x[n]=[2 3 4 5 0 0 0 0] corresponds to X[K]=[14 0.58-9.65i -2+2i -3.414+...
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Advantages/disadvantage of zero padding
I would like to know what are the advantages/disadvantage of zero padding with respect to frequency measurement and amplitude measurement
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How Much Zero Padding Do We Need to Perform Filtering in the Fourier Domain?
Consider an $M\times N$ image $f$ and an $G \times K$ filter $h$. Given that convolution in the spatial domain corresponds to multiplication in the Fourier domain, then we can perform a convolution of ...
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1answer
350 views
Zero padding effect on a FFT of gaussian noise
I have a gaussian noise $\nu(t)$ with variance $\sigma^2$. After a FFT I get $X(\omega)$. If now I do the IFFT on the $X(\omega)$ can I say that the result is still a gaussian noise of variance $\...
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3answers
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FFT Zero Padding - Amplitude Change
I'm just learning about Fourier Transforms and as an input I'm using a WAV file (Matlab) and taking one channel of it and performing a quick Fourier transform. I've zero padded the input, as I've been ...
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Re-implementing the “spectrogram” function from matlab
I am trying to make a spectrogram viewer without using the spectrogram command. For this purpose, I used a sin function. I broke up the input signal into 256 segments, multiplied each segment with the ...
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1answer
538 views
Zeropadding and amplitude scaling
Could somebody tell me what is the DFT scaling of a $N$-length signal which is padded with $M$ zeros ? Is it $1/(M+N)$ or $1/N$, i.e.
$$
Y_k=\frac{1}{N}\sum_{n=0}^{N-1}y(n)e^{\frac{2\pi nk}{(M+N)}} \...
