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Can the standard deviation of the Gaussian window in a Gabor filter be made infinitesimally small?

My understanding is that the standard deviation of the Gaussian window in a Gabor filter dictates the temporal resolution. Wouldn't it always be better then to make the window smaller, thus achieving ...
SNIreaPER's user avatar
2 votes
1 answer
341 views

What is the difference between STFT and Gabor filter?

My understanding is that a Gabor filter gives us information about when in the input signal does the frequency of interest (equal to the frequency of the sinusoid in the Gabor Filter) occur, thus ...
SNIreaPER's user avatar
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1 answer
125 views

What does a Gabor filter "filter" out?

Almost all of the searches online have returned results related to image-processing, but I am looking for a more rudimentary example with some physical intuition (eg; a high-pass filter only lets the ...
SNIreaPER's user avatar
4 votes
1 answer
83 views

Fingerprint enhancement lighter version

I've been advised to ask here, I hope that it fits. Original question: I want to create a more straightforward and lighter version of this fantastic repo (which itself is based on Fingerprint Image ...
RedYoel's user avatar
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1 answer
62 views

How do I solve for the normalization constant of a discrete time-frequency Gabor atom?

Given the mathematical expression for the discrete Gabor time-frequency atom $$g_{s,u,\omega,\theta}(n) = \frac{K_{s,u,\omega,\theta}}{\sqrt{s}} e^{-\pi(n-u)^2/s^2} \cos[2\pi\omega(n-u)+\theta]$$ ...
J. Herrera's user avatar
0 votes
0 answers
173 views

Gabor uncertainty and time-frequency resolution

I have a question about Gabor's uncertainty theorem, and how it relates to time and frequency resolutions. As I understand it, Gabor's uncertainty theorem states that the standard deviations of a ...
jacob's user avatar
  • 101
2 votes
1 answer
1k views

Difference between Gabor filtering and Discrete Wavelet Transform

Both Gabor filtering and discrete wavelet transform (DWT) analyze the image in both spatial and frequency domains, unlike Fourier transform which analyzes the image only in the frequency domain. What ...
Noha's user avatar
  • 349
-1 votes
2 answers
360 views

On generalizing Gabor-Heisenberg uncertainty in a noisy environment

The Gabor-Heisenberg uncertainty represents the fundamental limit of time and frequency resolution one can extract from a signal. $\sigma_t \sigma_f \geq \frac{1}{4\pi}$ My question is: what happen ...
pierebean's user avatar
3 votes
1 answer
98 views

The Concept of scales in Gabor filter

I've been reading about Gabor filters, and there is a concept of scale. While I understand that Gabor features help in analyzing both the frequency and orientations of an image, what is the idea of ...
Curiosity's user avatar
  • 367
0 votes
2 answers
608 views

Different ways of decomposing signals into sinusoids

For purposes of generating a spectrogram, the signal can be divided into overlapping chunks, each chunk multiplied by a window function and transformed to frequency domain using Discrete Fourier ...
tl13's user avatar
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1 vote
0 answers
265 views

How to plot even and odd parts of log-Gabor filter?

I am reading a paper inwhich there is a plot of log-Gabor quadrature pair which are even and odd. I'm wondering how these two are plotted in time-domain, since log-gabor is real valued in frequency-...
MJay's user avatar
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1 vote
1 answer
492 views

how gabor filter is used on image texture edge detection

as I searched gabor filter is most used tool on texture analysis and edge detection in digital image. its said that it searches a certain frequency as a texure around a pixel or point to find the ...
virtouso's user avatar
  • 277
1 vote
0 answers
467 views

Difference between Gabor filters, Gabor wavelets and Log-Gaber wavelets

I am a beginner in the field of image processing, and I am trying to understand Gabor transform but the more I read, the more I get confused. So I wish to find someone who can help me answering this ...
Hadeer Tawfike's user avatar
0 votes
1 answer
741 views

Image processing using Gabor filter

I need to compare images using Gabor filter. I cant seem to understand how to find a quantifiable value to compare through Gabor. Can someone give me steps to do the same. I got some code, but it ...
user24550's user avatar
0 votes
1 answer
275 views

What is the Center Frequency of Gabor Filter?

If the standard form of a Gabor function is as follows, $$ g_{\lambda, \theta,\varphi, \sigma,\gamma}(x, y)=\exp\left(-\frac{x'^2+\gamma^2y'^2}{2\sigma^2}\right)\cos\left(2\pi\frac{x'}{\lambda}+\...
user avatar
1 vote
1 answer
871 views

When should we use the full Gabor Function and when do we use only the real part?

In this YouTube video, we see that the guy is only using the real part of the Gabor Filter to implement his project. My questions are, When should we use the complex Gabor Function? When should we ...
user avatar
1 vote
1 answer
149 views

Imposing sparse structure in Gabor space

I have a 2-D signal collected in the frequency vs time domain. There is a feature of interest in this signal (a chirp) appearing at some arbitrary times which I have successfully extracted using a ...
Stephen Itschner's user avatar
2 votes
2 answers
1k views

Understanding this Gabor Filter equation

I am working on a project where I need to implement road edge detection. This research paper suits my requirement in the best way, so I am studying it: http://imagine.enpc.fr/publications/papers/...
nipunmaster's user avatar
0 votes
3 answers
2k views

STFT multiplied with Gaussian window vs STFT multiplied by rectangular window

I am currently analysing my signal by looking at its spectrogram to determine the sinusoidal frequency content at the local sections of my signal overtime. I can do my spectrogram in 2 ways: Directly ...
Joseph Roxas's user avatar
5 votes
1 answer
2k views

Issues with the smoothing operator in coherence estimation using the complex Morlet (Gabor) wavelet

The goal I wish to compute the coherence estimate using the continuous wavelet transform (CWT) of a real-valued signal with the complex Morlet (a.k.a. Gabor) wavelet. I compute the cwt of the signal ...
Ondřej Grover's user avatar
0 votes
1 answer
598 views

Gabor filter bank for gist features

I was reading a paper about Gist features. I was interested about its code implementation which i found it here). Into LMgist.m there is a function called createGabor, this is the code: ...
Davide_sd's user avatar
  • 103
1 vote
2 answers
2k views

How to visualize and understand Gabor filter using MATLAB

I am reading a paper, in which the author defines gabor kernels as : $$ \psi_{\mu,\nu}(x,y)=\frac{\lVert \mathbf{k}_{\mu,\nu} \rVert}{\sigma^{2}}\exp \left(-\frac{\lVert \mathbf{k}_{\mu,\nu}\rVert^{2}...
Swaroop's user avatar
  • 161
3 votes
0 answers
524 views

Box filter approximations for oriented gabor filters

I'm currently working on a library to generate synthetic fingerprints using the SFinGe method (by Maltoni, Maio and Cappelli) link :http://biolab.csr.unibo.it/research.asp?organize=Activities&...
AngelCastillo's user avatar
5 votes
2 answers
610 views

Is Gabor uncertainty a feature of the Fourier transform, or of nature?

By Gabor uncertainty, I mean the principle of uncertainty as applied to signals — with the result that you can't have arbitrary time and frequency localization. By way of background to my question, ...
kwinkunks's user avatar
  • 151
1 vote
3 answers
258 views

Is there any difference between the 2D continuous and discrete Gabor filter when it comes to MATLAB implementation

I want to know the difference between the 2D continuous and discrete Gabor filter when it comes to Matlab implementation. I found many files related to 2D Gabor filter on Mathworks File Exchange but I ...
Dr. Arslan's user avatar
10 votes
3 answers
23k views

Understanding the Gabor filter function

I need to implement a script for generating features from an input image by using the Gabor filter. I have no past experience of wavelets and I'm just learning Fourier analysis (I understand the basic ...
jjepsuomi's user avatar
  • 265
0 votes
0 answers
77 views

How can I apply a Gabor filter to a sine waveform?

I am an ECE student, and I am doing my project on underwater communication. The main concept of my project is to denoise the signal by using UFB and WPD algorithms, and giving that output to a ...
krishna's user avatar
5 votes
2 answers
7k views

Gabor filters for digital image processing

For the application of Gabor filters in feature-based (e.g. lines and edges in images) digital image processing, it is desired that the DC component is 0. Why is this so? What effect does it have ...
meta_warrior's user avatar
0 votes
2 answers
166 views

how can i call the input data in wavelet transform and generate code for gabor wavelet manually? [closed]

I am an ECE student, and i am doing my project I want to generate a code for gabor wavelet transform. I have no idea could you help me with a sample program I have DNA as input sequences and how ...
chrish's user avatar
  • 11
3 votes
1 answer
769 views

proving that a log gabor filter has 0 DC offset

I have read somewhere online that the log gabor filter has an advantage over the gabor filter, in the sense that it has 0 DC component. How do you prove this property mathematically? Thanks in advance....
user1734134's user avatar
1 vote
2 answers
471 views

Apply Singular Value Decomposition on Gabor filters

According to my question in this link, I applied (with a big help from lennon310) the separability of Gabor filters of any orientation. The only disadvantage of this method is the convolution in the ...
Christina's user avatar
  • 239
5 votes
1 answer
4k views

difference between Gabor and log-Gabor function

I am reading a paper using log-gabor filters for feature detection. I was thinking about the difference between Gabor filters and log-gabor filters. Can anyone tell me the difference(s), and a way to ...
meta_warrior's user avatar
0 votes
1 answer
264 views

filter bank of gabor filters with different frequencies and orientations

I was reading a paper which uses a filter bank of gabor filters with different frequencies and orientations. However, I often see the construction of a filter bank of gabor filters with different ...
meta_warrior's user avatar
1 vote
1 answer
646 views

gabor wavelet and gabor transform

I was reading a paper 'A Flexible Framework for Local Phase Coherence Computation' (paper URL) on using wavelets for local phase coherence. I just want to be sure. Is the gabor wavelet the same as the ...
meta_warrior's user avatar
0 votes
1 answer
596 views

Book recommendations on Gabor filter and Fourier series

I'm starting to learn about Gabor filters and Fourier series. I need to make a presentation on Gabor filters in a few months, so I need quality references for the presentation. Does anyone have any ...
jjepsuomi's user avatar
  • 265
2 votes
2 answers
487 views

Precalculate the Normalization of a filter size

If we have an Image I and a Gabor filter created at specific size and orientation, assume that is 11x11. I saw some persons who normalize the size of the filter, ...
Christina's user avatar
  • 239
0 votes
1 answer
199 views

Convolution in Image Processing

Does anyone know how to write arg min code in matlab with explanation? I am referring to a paper for my research. I am not sure whether I can paste the paper link here. At first, I try to do feature ...
user7186's user avatar
0 votes
1 answer
908 views

Gabor Filter Parameter

I am doing research on images using gabor filter. I have read the following post: Apply a Gabor filter to an input image There must be some formula to determine the value for gamma,sigma,lambda,psi....
user7186's user avatar
0 votes
1 answer
148 views

frequency components of discrete Gaussian-windowed signal

When we are do a discrete Gabor transform on a 1D signal, we apply a Gaussian window on a segment of the signal. However, due to the tapering ends of the Gaussian window, the magnitude of the data ...
meta_warrior's user avatar
1 vote
1 answer
741 views

Removal the DC Component of Gabor Filters

I recently was studying gabor filters and came to know that they have a shortcoming that they do have a minimum but some reasonable dc component. now my question is why is it necessary to remove the ...
xor's user avatar
  • 137
1 vote
1 answer
766 views

window for short time fourier transform

When we implement the 1D-short time fourier transform, the formula is as such: $$ Sf[m,l]=\sum_{n=0}^{N-1}f[n]g[n-m]\exp\left(\frac{-i2\pi l n}{N}\right). $$ the window $g$ used is normally ...
meta_warrior's user avatar
5 votes
1 answer
1k views

Motivation for using gabor transform instead of fourier transform

I am trying to understand the motivation for the above question for signal processing and image processing? Can anyone answer this question, or provide me with resources for this?
meta_warrior's user avatar
1 vote
1 answer
312 views

Variance of the Discrete Gabor Transform for practical implementation

When we design a discrete Gabor filter for a 1D signal, how do we determine the variance of the filter, depending on the time step of the signal? Is there any empirical theorem/result that we should ...
meta_warrior's user avatar
1 vote
0 answers
86 views

Errata Corridge in Gabor Filter Documentation and Frequency Response

I have a really simple question regarding this tutorial I found on Gabor filters. Check the very beginning section, equations (1), (2), (3) and (4). Is there any chance that equation (4) is missing ...
Matteo's user avatar
  • 251
2 votes
1 answer
321 views

How do I start studying Gabor Filters ?

I know very basic image processing. Please suggest me how do I and where do I start learning Gabor Filters ?
siddharth's user avatar
  • 353
11 votes
4 answers
5k views

What's the difference between the Gabor-Morlet wavelet transform and the constant-Q transform?

At a glance, the constant-Q fourier transform and the complex Gabor-Morlet wavelet transform seem the same. Both are time-frequency representations, based on constant-Q filters, windowed sinusoids, ...
endolith's user avatar
  • 15.8k
1 vote
1 answer
706 views

Difference between Gabor filter implementations

I was reading a paper and came across this: I'd like to implement this in matlab, therefore I initially searched for a premade implementation. I stumbled upon this: http://www.mathworks.com/...
Olivier_s_j's user avatar
22 votes
3 answers
31k views

What is the Gabor filter? And what are its main uses?

I'm doing research on the Gabor filter. When I Googled it, I found very long and complicated articles. Can anyone help me to find a simple explanation about it, or recommend a website or article to ...
toto's user avatar
  • 221