Stack Exchange Network

Stack Exchange network consists of 174 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange
Join us in building a kind, collaborative learning community via our updated Code of Conduct.

The tag has no usage guidance.

1
vote
0answers
35 views

Understanding Gabor filter

In Accord.net framework, two classes are used to construct a Gabor filter: Accord.Math.Gabor Accord.Imaging.Filters.GaborFilter There are various implementations of Gabor filter elsewhere: ...
0
votes
0answers
14 views

Feature Extracting from an image from JAFFE database using gabor filter

I am trying to implement a feature extractor using gabor filter in MATLAB. I have taken images from the JAFFE Database. Here is my code: ...
1
vote
0answers
25 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-...
0
votes
1answer
220 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 ...
1
vote
0answers
262 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 ...
0
votes
1answer
212 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 ...
0
votes
0answers
111 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}+\...
1
vote
1answer
172 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 ...
1
vote
1answer
96 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 ...
2
votes
2answers
744 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/...
0
votes
3answers
592 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 ...
5
votes
1answer
778 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 ...
0
votes
1answer
372 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: ...
1
vote
2answers
1k 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}...
2
votes
0answers
323 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&...
4
votes
2answers
290 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, ...
1
vote
0answers
72 views

question about the frequency of Gabor filters

The Fourier transform of 2D Gabor filters is shown below: F is the radial frequency of the Gabor functions. Another parameter Fm is denoted as highest central frequency. Fr is the constant frequency ...
-1
votes
2answers
185 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 ...
8
votes
3answers
14k 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 ...
0
votes
0answers
72 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 ...
5
votes
2answers
5k 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 ...
0
votes
2answers
139 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 ...
3
votes
1answer
503 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....
0
votes
2answers
335 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 ...
5
votes
1answer
3k 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 ...
0
votes
1answer
213 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 ...
1
vote
1answer
403 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 ...
0
votes
1answer
367 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 ...
2
votes
2answers
341 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, ...
0
votes
1answer
137 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 ...
0
votes
1answer
716 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....
0
votes
1answer
127 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 ...
1
vote
1answer
515 views

Need of removal of dc component

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 ...
1
vote
1answer
566 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 ...
3
votes
3answers
555 views

strange phenomenon in spectrogram of Windowed Fourier Transform [edited] [closed]

I am trying to understand how the Windowed Fourier transform works, so I used Matlab to create an artificial signal, and plotted the Windowed Fourier transform using a gaussian window. $x(t) = \left\...
4
votes
1answer
301 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?
1
vote
1answer
248 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 ...
1
vote
0answers
82 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 ...
2
votes
1answer
278 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 ?
9
votes
3answers
3k 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, ...
1
vote
1answer
519 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/...