Linked Questions
14 questions linked to/from Power/Energy from Continuous Wavelet Transform
23
votes
2
answers
13k
views
Synchrosqueezing Wavelet Transform explanation?
How does Synchrosqueezing Wavelet Transform work, intuitively? What does the "synchrosqueezed" part do, and how is it different from simply the (continuous) Wavelet Transform?
- 9,064
9
votes
5
answers
2k
views
Identify abrupt changes in an audio waveform
I have an audio file which was created by substituting multiple speech segments into an original utterance.
I want to find the timestamps where such substitutions happened, so I guess that one thing I ...
- 143
8
votes
2
answers
1k
views
Is there an equivalent of Parseval's theorem for wavelets?
Parseval's theorem can be interpreted as:
... the total energy of a signal can be calculated by summing power-per-sample across time or spectral power across frequency.
For the case of a signal $x(...
- 225
6
votes
3
answers
2k
views
Role of window length and overlap in uncertainty principle?
I am trying to predict epilepsy using spectrograms and a convolutional neural network.
So far I have achieved a validation accuracy of 86% which i feel like is pretty good. Lots of the papers doing ...
2
votes
2
answers
929
views
What is "filter periodization"?
A library defines periodize_filter_fourier, which is an equi-spaced averaging formulated by
$$
v_f[k] = \sum_{i=0}^{\text{n_periods}-1} h_f[i\cdot N + k],
$$
where $v_f$ is periodization of $h_f$, $N=\...
- 9,064
2
votes
2
answers
829
views
One integral inverse CWT
MATLAB's icwt docs state inversion to be done by a single integral:
$$
f(t) = 2 \Re e\left\{
\frac{1}{C_{\psi, \delta}} \int_0^\infty \left< f(t), \psi(t) \right> \frac{da}{a} \tag{1}
\...
- 9,064
1
vote
2
answers
824
views
Relationship between energy, power and sampling rate?
Excuse my silly question, but I think the energy increases as the sampling rate increases. In the time domain, the number of samples increases so the energy increases; In the frequency domain, ...
- 11
1
vote
1
answer
651
views
Why is inverse CWT inexact / inaccurate?
I'm all new to wavelet analysis. I'm trying to get a working understanding of the continuous wavelet transform and its inverse.
By "working understanding", I really mean "getting some ...
- 117
3
votes
2
answers
380
views
Calculating signal power from Continuous Wavelet Transform in MATLAB
I would like to ask a question about the calculation of the signal power using CWT in Matlab. Assume a signal of length N points with sampling frequency $f_{s}$. Using conventional approach, the power ...
- 31
0
votes
1
answer
471
views
Inverse continuous wavelet transform off by constant factor in the y axis
I have implemented the Continuous Wavelet Transform using the pycwt library(https://github.com/regeirk/pycwt/blob/master/pycwt/wavelet.py) and its inverse using Morlet wavelets, however, upon ...
- 189
-1
votes
2
answers
306
views
python plt.specgram the number of xaxis' value when I change nfft, overlap
I am trying to use plt.specgram
But I found something weird in the x-axis setting.
My data is as below..
...
3
votes
1
answer
123
views
Littlewood-Paley Conditions, Scattering, and Multi-Resolution Analysis
So I am trying to understand the scattering transform on graphs (GST). There are many formulations but I am stuck on equation 8 in this paper. Here they give a condition on a wavelets that looks like ...
0
votes
0
answers
63
views
In continous wavelet transform, all wavelets must have the same energy regardless of their scales,why?
In Continuous Wavelet Transform (CWT) To achieve energy normalization and to ensure that all wavelets have the same energy regardless of their scales, each wavelet is divided by the square root of the ...
0
votes
1
answer
57
views
Strided unpadding energy relationship?
If x1 = x0[::2] is unaliased subsampling, then $E(x_1) = E(x_0)/2$, which can be proven via Parseval's theorem.
For same $x_0, x_1$, however, ...
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