Questions tagged [fast-wavelet-transform]

The tag has no usage guidance.

Filter by
Sorted by
Tagged with
1 vote
1 answer

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 ...
S.EB's user avatar
  • 163
2 votes
1 answer

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 ...
Johncowk's user avatar
  • 141
2 votes
1 answer

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 ...
The Wanderer's user avatar
1 vote
2 answers

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 ...
Wang Yun's user avatar
  • 124
3 votes
1 answer

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 ...
Eddy Piedad's user avatar
0 votes
0 answers

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] = <...
Elenie's user avatar
  • 1
2 votes
1 answer

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: ...
Arrigo's user avatar
  • 21
1 vote
1 answer

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 ...
2p718's user avatar
  • 11
1 vote
1 answer

Does the Fast Wavelet Transform produce the same coefficient as the Discrete Wavelet Transform?

Does the Fast Wavelet Transform(FWT) produce the same coefficients as the Discrete Wavelet Transform(DWT) if configured for the same depths? Or is the the FWT just an approximation of the DWT?
Izzo's user avatar
  • 803