Incorrect FFT of Gaussian kernel

I'm trying generate the FFT of a Gaussian kernel to use in later filtering. My understanding is...

Is the OpenCV phase() function working correctly in this edge case?

I'm using OpenCV 3.2.0 to do some Fourier space calculations. To obtain a phase image after an...

Fourier descriptors in MATLAB

I'm trying to find the matching score between the boundary of shapes that do not exactly match. I...

Use Discrete Fourier Transform to calculate infinite periodic spectrum

Using open cv, I am able to gleaning heavily from the example here. And given the input image...

How can I fix dimension error while trying to compute and plot Fourier coefficients

I am trying to compute and plot Fourier coefficients for some signal and I am getting the following...

I have the equation in frequency domain; How to go back in time and space domain with IFFT?

I have the solution of an equation (analytic solution) in frequency domain; How to go back in time...

What is the difference between numpy.fft.fft and numpy.fft.rfft?

The documentation says that np.fft.fft does this: Compute the one-dimensional discrete Fourier...

Odd function used for signal processing?

ฮello! I hope this is an acceptable sort of question. Going through some code used for signal...

How to calculate Frequency with Fast Fourier Transformation

i am working on a pulse sensor project. I get data from the sensor like this: Now i would like to...

How to approximate a sound using coefficients with Web Audio API

Here is what I am trying to do: I would like to take a WAV file (for example, let's say...

What is the difference between this two types of kernels?

Suppose, I have a Spatial kernel function ๐(๐ฅ, ๐ฆ), and an image ๐ผ(๐ฅ, ๐ฆ) of...

Question regarding filtered back projection algorithm

Suppose I have a unit circle centered at the coordinate system and I perform filtered back...

Both fast and very slow scipy.signal.resample with the same input size

According to the documentation of scipy.signal.resample, the speed should vary according to the...

MATLAB Dftmtx for Huge "N"

I have a vector of size M (say 500), which I up-sample by a factor of MM=500, so that my new vector...

Matlab: fourier coefficients of sign() function are oscillating

I'm writing a function that takes in a time-varying signal and returns the FFT. It follows the...

How to combine the phase of one image and magnitude of different image into 1 image by using python

I want to combine phase spectrum of one image and magnitude spectrum of different image into one...

Fourier transformation with audio input in python

I want to recognize voices using a neural network, to do that I need to first get a good input for...

Implementing FFT over finite fields

I would like to implement multiplication of polynomials using NTT. I followed Number-theoretic...

How to perform Shift zero-frequency component to center of spectrum in Accord.Net?

I wonder how to do something like Shift zero-frequency component to center of spectrum (matlab...

OpenCV DFT output switch between packed and complex representation

Applying opencv dft on a real 1-channel Mat, I can use DFT_COMPLEX_OUTPUT flag to control whether...

FFT - Peak to Peak, Peak, RMS

I work with vibration, and I am trying to get the following information from a FFT...

Having a complex-to-complex 2D FFT, how to do 3D FFT?

Say we have a 2D complex-to-complex FFT implemented. How we can now use it to implement 3D FFT - is...

Is this FFT from complex to complex or a bug?

So I try to read this code. And judging from Texture2D<float2>...

Calculate fft for each column or row in matrix

I have a problem with calculating fft for a signal which is stored in a matrix using matlab. I am...

Bit-reversal algorithm by Rutkowska

I found a very interesting paper about bit-reversal algorithm suitable for in-place FFT: "A simple...

How to fix shift and scaling errors in an FFT-powered differentiation program?

So I am trying, like many others before me, to sift through all the celestial alignments of phase...

FFTW in Fortran result contains only zeros

I have been trying to write a simple program to perform an fft on a 1D input array using fftw3....

Remove a line in image with FFT

I would like to remove vertical line from an image (an example). I took a 2D FFT and try to apply a...

Amplitude and phase spectrum. Shifting the phase leaving amplitude untouched

I have the data that has equivalent intervals and corresponding measurements at relevant points. As...

Why does the following FFT result in a different set of frequencies than that used for generation?

I generate the an audio file SingleTone.wav using the following sox command. sox -n SingleTone.wav...