# Questions tagged [fast-wavelet-transform]

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### Conjugate symmetric: 3D fourier transform dirmension

I have a real value input 3D tensor with the shape of `(H,W,D)=[8,8,20]', where H, W, and D represent height, width and depth in (z dimension), respectively. When converting to the DFT, what will be ...
• 163
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### Is there a reason why wavelet in continuous wavelet transform are symmetric?

I have looked at several packages to do continuous wavelet transform (cwt), and the usable wavelet families that are available are always symmetric. Is there a reason for that? The kind of signals I ...
• 141
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### Wavelet transformation to analyse time series

I am new to wavelet transformation. I am learning it as a tool for signal processing. I have a time series that I want to analyze. I tried to learn wavelet transformation by applying it to a periodic ...
1 vote
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### Questions about the paper titled "Rapid computation of the continuous wavelet transform by oblique projections"

This paper introduced a fast method for computing the real CWT and achieved $O(N)$ complexity per scale. However, in the context of this article, I'm not sure what the definition of oblique projection ...
• 124
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### Does Fast Continuous Wavelet Transform (fCWT) have theory-supported novelty or just simply a computation optimization?

A recent publication, The fast Continuous Wavelet Transform (fCWT), enables real-time, wide-band, and high-quality, wavelet-based time–frequency analysis on non-stationary noisy signals. I'm a ...
• 157
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### Difference between Discrete Wavelet Transform and convolution

Sorry in advance if my question is too dumb. I'm going through the book of Mallat, and from what I understand, the approximation/wavelet coefficients $a_j[n] = <f, \phi_{j,n}>$ and \$d_j[n] = <...
633 views

### How could I do a Discrete Fourier Transform in Python if my data is non uniform?

I have been trying to find a way to transform my time series data in an equivalent manner to the discrete Fourier transform. What I wish to find is something like: ...
• 21
1 vote
342 views

### Why discrete wavelet transforms use sampling rate 2 and need signal length to be a power of 2?

I know Fourier transforms but new to wavelet transforms. I can understand Haar transform needs signal length a power of 2, since the filters have 2 taps and down-sampling and up-sampling in the ...
• 11
1 vote