Zero padding consists of extending a signal (or spectrum) with zeros to extend its time (or frequency band) limits.

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### How to Zero Pad in Order to Perform Filtering in the Fourier (Frequency) 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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### Zero padding in frequency domain, any tricks to speedup?

there are many situations when one has to carry some operations on spectra, like splitting a spectrum Z wide in two Z/2 spectra, or vice versa merging two Z sized spectra in a 2Z sized one. The only ...
81 views

### Does zero-padding distort the spectrum?

It's said to "sample the DTFT", revealing what "DFT fails to see". And I fail to see how this sampling isn't distortion. The "spectrum" aims to provide the sinusoidal ...
24 views

### Zero Padding in image reconstruction

I need to zero-pad the image for a better reconstruction but according to my project details, I will be given a Fourier-transformed image so can someone tell me how to pad the image in such a ...
1k views

### How do I calculate peak amplitude of the signal components after zero padding and FFT?

I am learning about DFT and trying to apply it to some audio processing. I am new to DSP but experienced in programming and have some background in math and physics. The FFT algorithm I use (lomontFFT)...
221 views

### Matlab: Different 1-D FFT results with and without zero-padded

Recently I am implementing FFT with C code. So I use Matlab for algorithm verification. As Radix-2 FFT was chosen, I've learned that zero-padding technique could help to reach 2^N limitation without ...
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### Meaningfulness of Frequency Spectrum for Classification

I just started to dive into signal processing due to a free-time project. Therefore, this is my first question here, for which I searched many previous threads, but couldn't find what I was looking ...
164 views

### Zero padding issue - cut the buffer

I have some issue with zero padding. It's probably because I don't understand it enough. I have buffer size set to 400. And I use radix-2 fft. So I take the input signal 400 samples, and add to them ...
42 views

### How much zero padding I should do to an audio signal before fft?

I was working on project and I need to do fft to my audio signal. I was going through a code and found following line. Can anyone explain me the line of code. ...
40 views

### The impact on the frequency of adding zero samples and non zero samples

Can someone give me a brief explanation of what is going on in here? I struggle to understand the full differences between the impact on the frequency of added zero samples and adding samples which ...
26 views

### Adding zeroes in between the samples of a discrete frequency domain leads to both zero padding and scaling

I won’t show ALL the calculations, but I’ll describe the problem fairly enough to understand. We’ve been taught that upsampling on one domain leads to padding zeroes or added time period which is zero ...
23 views

### Different type of padding in image?

I want to implement a gradient operator on an image in Matlab. Should I have to pad the image before its implementation? How do I decide which padding to use e.g. whether to use zero-padding or ...
106 views

### Why is my time domain interpolation via zero-padding in frequency domain wrong?

Since the process can be applied in either domain to increase the sampling rate in the other domain, I am trying to apply zero-padding in frequency space to recover a 'cleaner' interpolated signal in ...
68 views

### Alternative Methods to Zero Padding

When using a sequential neural network to classify signals with their frequency spectrum, we would need to normalize the length of the signals to perform vectorization. The only method I'm aware at ...
40 views

### Zero-padding or Interpolation in 3D FFT

I'm trying to perform a FFT of a 3D regular grid and then compute the bin average (in spherical shell bins) of the Fourier transformed grid. The problem is that the resulted vector is very noisy as I'...
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### How to optimize padding and truncating of signal

I 6000 signals that vary between 3000 and 30000 in length In the figure under you can see that most of the signals are of length 5000. So I decided to pad and truncate all signals to 10000 and feed ...
7k views

### How does zero-padding affect the magnitude of the DFT?

Let's simulate sinusoids of two frequencies using the following Matlab code: ...
45 views

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### How Exactly Does MATLAB Zero Pad Signal?

I am doing some massive number crunching in MATLAB which involves millions of PSD estimations. Each data segment has length 41. So I have been using the multi-taper method with ...
115 views

### Why padding zeros in the middle of a DFT spectrum improves original signal reconstruction?

I'm experimenting with the Inverse Discrete Fourier Transform. Starting from the two-cycles continuous $x(t)$ signal below: I have the discrete signal $x(n) = \{ 1, 0, -1, 0, 1, 0, -1, 0 \}$ leading ...
58 views

### Cepstrum calculation with 5-smoothing zero padding

I am trying to compute cepstrum of a signal x An implementation of this in python is: ...
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### What does it mean when you zero pad data and why does one do it? [duplicate]

I am struggling to understand what effect zero padding data would have on EMG data. How does it improve the signals? Any help in simple terms that's not too mathematical would be greatly appreciated!
240 views

### Is image padding really necessary while using a filter?

I do know that we must pad an image while using a filter. But what I am suggesting is that is it really necessary? Can't we just calculate at run time if the current cell/pixel is an edge cell/pixel ...
5k views

### 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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### 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 ...
442 views

### Spectral window when FFT is not a power of 2

I am trying to better understand zero padding and the FFT. To do so, I am attempting to plot the spectrum of the Hann window function, i.e.  w(n) = \frac{1}{2}\left(1-\cos\left(\frac{2\pi (n+1/2)}{...
621 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? ...
632 views

### remove zero padding effect crosscorrealation

I am trying to make the cross correlation on the frequency domain and I use the fft function which takes power of 2 input data so I must pad with zero my incoming sample signal and localy generated ...
Consider an array with $t=10000$ rows, $i=2$ columns and $n=41$ as a 3rd dimension. Now I add the columns of this array to yield a matrix with $t$ rows and $n$ columns. However in MATLAB the size of ...