The fourier tag has no wiki summary.
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Points of interest in a spectrogram
We have several audio tracks, all of which are different versions of the same track under one type of distortion: the speed of the track is increased by a constant factor K (hence frequences are ...
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Normalized cross correlation via FHT - how can I get correlation score?
I'm using the 2D Fast Hartley Transform to do fast correlation of two images in the frequency domain, which is the equivalent of NCC (normalized cross correlation) in the spatial domain.
However, ...
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What do colored noises look like in the time domain?
I understand that the time domain representation of white noise looks like impulses. How do colored noises like brown, pink etc. look like when we perform an inverse Fourier Transform on them ? What ...
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Intuition for how a Fourier transform handles signals where the frequency varies with time?
I created a discrete signal sampled at 44.1kHz that is 330Hz for 1 second, 360Hz for 0.5s, and 390Hz for 0.25s. I did an FFT transformation of this, and got the magnitude graph below:
I don't ...
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1answer
138 views
Signal Processing using Fourier Transform
So I'm trying to understand how MRI machines work. I understand all the concepts of it, the parts, what they do, how the machine works, etc. The part I'm having trouble with is the fourier transform ...
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Fourier Transform minimum sample requirement
Assuming a signal is sampled adequately, what is the minimum size of an FFT window that would allow detecting a specific frequency? Is it necessary to have samples for at least one complete period at ...
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Fast Fourier transform- non-integer number of cycles in the FFT aperture
There are a few excellent discussion threads and answers on this site (eletronics.se) on the theory of Fourier transforms. I tried implementing the same in a simulation tool (MS Excel :)).
I have a ...
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1answer
209 views
Mathematics / Signal theory behind billiard ball 'wave pendulum' effect
This YouTube video shows a very interesting effect.
What is the underlying science?
I have recently started studying Fourier theory and DSP, and and trying to understand what is going on in terms of ...
