Questions tagged [decomposition]
The concept of signal decomposition relates to the need to separate one component from the others in a signal; this can be achieved through a filtering operation which require a filter design stage.
77 questions
1 vote
2 answers
162 views
Robust Extraction of Local Peaks in Noisy Signal with a Trend
I'm looking to a way to detect peaks in Matlab for noisy random signals generated by IMU's accelerometers. The signal could be approximate to a sinusoidal-like signal with zero mean and random noise ...
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3 votes
1 answer
149 views
Why does the DCT-II have better energy compaction than DCT-I?
I have some code to take coefficients of a signal with one of the DCT variants, then reconstruct with the inverse transform in this notebook. I'm seeing I can reconstruct a signal with better fidelity ...
- 287
0 votes
0 answers
43 views
Getting amplitude from messy signal
I'm working on analyzing some data from a grain boundary in an atomic simulation. I've got a lot of similar data to go through and am trying to determine a reliable way to get the amplitude of my ...
0 votes
0 answers
48 views
How can we prove using matlab that after each level of decomposition of a signal using DWT the frequency content is halved?
I was trying to decompose an EMG signal, which was sampled at 200 Hz, into 7 levels of decomposition using DWT. And the result is shown in the figure( only up to level 3 is shown here) However, I ...
6 votes
4 answers
4k views
Smooth envelope of an aperiodic signal
I have a signal that looks like this: Red line is the function I'd like to obtain somehow. Everything <= -60 is basically absent data (i.e. not low signal). If I understand correctly, Hilbert ...
- 183
4 votes
1 answer
96 views
Video Alpha Matting
I'm looking to composite an opaque object (e.g. 3D art) into video footage of semitransparent fog/clouds before a landscape background so that the object seems immersed in the clouds but occludes the ...
- 41
1 vote
3 answers
409 views
How to estimate the local trend in a signal?
I need to remove trend from my time-series which looks like the following images. However, I want to estimate the trend before removing it. Hence directly removing it won't do it. The simple ...
- 417
1 vote
1 answer
741 views
Narrow bandpass filtering
I want to plot a specific frequency (e.g., 1 kHz or 100 Hz) of an audio file (sampling rate 44.1 kHz). I have done fft and spectrogram analysis on the file, but I am now interested in plotting only ...
- 13
1 vote
0 answers
71 views
Amplitude and phase from variational mode decomposition?
If a VMD analysis were fairly successful, in the sense that the spectrum is unimodal and relatively sparse, but still with a bit of bandwidth is it possible to extract a meaningful local amplitude and ...
- 131
1 vote
1 answer
2k views
Creating a polyphase filter
I need to design a 3/2 resampling filter using polyphasic filters. On my original filter I have coefficients $$h[n] = [a_0, a_1, a_2, a_3, a_4, a_5, a_6, a_7, a_8, a_9, a_{10}, a_{11}]$$ making it an ...
0 votes
1 answer
215 views
Signal sawtooth decomposition
I'm interested in analyzing a windowed signal in terms of a weighted sum of sawtooth waves. Being a somewhat DSP newbie, is there an obvious approach to this? I realize that sawtooth waves don't form ...
- 3
5 votes
2 answers
408 views
A self-supervised learning technique to denoise my specific signal
So I work in this domain of biophysics that has to do with a light-based detection for measuring small movement of molecules (nanometer and piconewton scale) via a Quadrant Photodiode. This signal ...
2 votes
2 answers
967 views
Why do we decompose signals to even and odd
I was learning the decomposition of a signal into one even signal and one odd signal: $$x(t) = x_{e}(t)+x_{o}(t)$$ with $$x_{e}(t) = \frac{1}{2}\cdot [x(t)+x(-t)]$$ and $$x_{o}(t) = \frac{1}{2}\cdot [...
- 237
3 votes
1 answer
400 views
Why does NMF (Non Negative Matrix Factorization) decompose a spectrogram into time and frequency component?
I compute the NMF over a spectrogram (magnitude of STFT of a signal) in this way: W,H = NMF(MyStft,r) # where r=2 is the rank W and H respectively contain the ...
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2 votes
2 answers
509 views
making a laplace s-domain plot from numerical data to decompose signal into decaying sinusoids
I would like to make a 3D laplace s-domain plot from experimental data I have. The examples I have seen for this are when the function is already known and an analytical solution can be obtained (...
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