## Forums Search for: Wavelets

## wavelets - vanishing moments - what are they?

inHello, Can anyone give a _very_ simple explanation / definition of what vanishing moments are in the field of wavelets please? I'm...

Hello, Can anyone give a _very_ simple explanation / definition of what vanishing moments are in the field of wavelets please? I'm reading Hubbard's the World According to Wavelets and the book keeps using the phrase vanishing moments but annoyingly hasn't really introduced nor explained them. Thanks, Ben.

## Representation theorem for wavelets

inHi all. In Real Analysis there is a theorem (Weierstrass'?) that any "reasonable" function can be approximated to arbitrary presicion by...

Hi all. In Real Analysis there is a theorem (Weierstrass'?) that any "reasonable" function can be approximated to arbitrary presicion by means of any linear basis for the function space, or |f(x) - sum_n=0^\inf g_n(x)| < eps where g_n(x) is the set of basis functions. This is "easy" to see/derive for basis functions like complex sinusiodals that have a finite magnitude for all x.

## Relation between filter banks and wavelets

inHow wavelets and filter banks are related? Why we use the second in order to implement the first? thank you

How wavelets and filter banks are related? Why we use the second in order to implement the first? thank you

## dyadic grid and wavelets

inIn the following link http://perso.wanadoo.fr/polyvalens/clemens/wavelets/wavelets.html#section4 there is a dyadic grid. Can you explain me what...

In the following link http://perso.wanadoo.fr/polyvalens/clemens/wavelets/wavelets.html#section4 there is a dyadic grid. Can you explain me what this grid shows? thank you

## I need ..

inHello, I need these two books: 1. First Course in Wavelets and Fourier Analysis, by Bogess & Narcowich 2. Pattern Recognition and Image...

Hello, I need these two books: 1. First Course in Wavelets and Fourier Analysis, by Bogess & Narcowich 2. Pattern Recognition and Image Processing Thanks for time an your response is much appreciated. Sincerely, Kal BC, Canada

## Wavelets

inhi there, I tried to display the audio signal from WAV file, which is in real time domain. I have to identify the the noise position, it's...

hi there, I tried to display the audio signal from WAV file, which is in real time domain. I have to identify the the noise position, it's time and how much is the amount of noise presented. For that I decided to transform those time domain signals into frequency domain signals with the help of DWT, since I want to know the position and level of noise wrt. milliseconds. I tried to implement it...

## Clustering using wavelets

Is there any way by which wavelets can be used for clustering??

Is there any way by which wavelets can be used for clustering??

## Data Fusion Using Wavelets

inHi Guys , I am working on a project on data fusion using wavelets and want some information on the background info on wavelets and data fusion....

Hi Guys , I am working on a project on data fusion using wavelets and want some information on the background info on wavelets and data fusion. Could anyone suggest something? Thanks in advance, Radhika Tharol.

## A Fourier/Wavelets link resource

While searching http://mathforum.org/, which describes it self as "... a research and educational enterprise of the Drexel School of Education",...

While searching http://mathforum.org/, which describes it self as "... a research and educational enterprise of the Drexel School of Education", I found the following " Browse and Search the Library Home : Math Topics : Analysis : Fourier/Wavelets " http://mathforum.org/library/topics/fourier/ Their site map map also be of interest. http://mathforum.org/library/toc.html

## How to choose wavelets for an application?

You know, there are many different wavelets. How to determine which one fit an application best?

You know, there are many different wavelets. How to determine which one fit an application best?

## Finding the main frequency of an input audio signal

inWhat is the best/easiest method to determine the main frequency of the input audio signal? I am confused by some options (FFT, wavelets) and I...

What is the best/easiest method to determine the main frequency of the input audio signal? I am confused by some options (FFT, wavelets) and I am just looking for a simple one which doesn't have to be too much theory, but simply works. I still would like to learn something, not just reuse somebody's solution in part or in whole and not understand anything, but I wouldn't like to spend more th...

## Nonlinear time series analysis and wavelets

inLately I have read a number of articles that use multiscale analysis (wavelets) to decompose the signal into different frequency bands. On each of...

Lately I have read a number of articles that use multiscale analysis (wavelets) to decompose the signal into different frequency bands. On each of the scales, invariant measures such as correlation dimension and largest Lyapunov exponents are estimated (via Takens delay embedding theorem). My questions are: Since linear filters are generally not recommended as a preprocessing step before calculati...

## Image segmenation using gabor wavelets - help needed.

Hi friends, i am dinesh. i am doing texture analysis and image segmenatation using gabor wavelets in java.. so far i have successfully...

Hi friends, i am dinesh. i am doing texture analysis and image segmenatation using gabor wavelets in java.. so far i have successfully finished doing texture analysis using gabor wavelets.. now i have to do image segmentation.... actually my work is decamouflaging, that is multiple camouflage breaking, finding the objects that are hidden in the given image because of its same texture as t...

## anybody help me to implement multiwavelet denoising

inDear all, First of all can anyboday tell me that whether multiwavelets and multiple wavelets are the same? i am trying...

Dear all, First of all can anyboday tell me that whether multiwavelets and multiple wavelets are the same? i am trying to implement multiple wavelets for decompostion and denoising.The decompostion, i have to use the function mdwt .i dont know what will be the arguemnts for that function.Also can i do multiple wavelets for denoising highpass subbands.If so can you help me in ...

## Wavelets and Reflection image question

Hi all, I've recently begun trying to understand the fundamentals of lossy image compression via transforms such as DCT and...

Hi all, I've recently begun trying to understand the fundamentals of lossy image compression via transforms such as DCT and Wavelets (CDF9/7). In a paper I was reading it suggested that prior to applying a forward transform that a "reflection image" of the original image be created. This involves flipping the image vertically and horizontally and copy those flipped variants above, be...

## Wavelets

I'm interesting learning about wavelets. Can anyone suggest the best books for good coverage of the topic? Also, do wavelets have any...

I'm interesting learning about wavelets. Can anyone suggest the best books for good coverage of the topic? Also, do wavelets have any application to control systems, or it mostly a DSP thing?

## How Shifting and Scaling in Continous signals is related to Images

inHello Everybody! I am doing a study of wavelets. I am able to get basic idea of wavelets as how the input signal is multiplied with a scaled...

Hello Everybody! I am doing a study of wavelets. I am able to get basic idea of wavelets as how the input signal is multiplied with a scaled and shifted windowing function.But I am not clear of how the filtering process is carried out for 2-d matrices or images. Can anybody tell me how shifting and scaling of wavelets in continous time signals is related to images. Thanks in advance! Narin...

## Need Formulas For Mean & SE/SD of Some Things

I'm writing an open source software toolkit for multiscale autoregressive modeling with wavelets (http://www.dataraptor.net/ MSARW/). As part of...

I'm writing an open source software toolkit for multiscale autoregressive modeling with wavelets (http://www.dataraptor.net/ MSARW/). As part of an upgrade, automatic fitting procedures are being added. For this upgrade, I need the mean and variance, a way of testing values of the parameters listed below or both. I've made an extensive Google search and found nothing. Any help is appreciated....

## DSP interview questions : Please Contribute questions and answers here

inHi, I have been called for an interview for phd in signal processing from an institute which does research in physics and astronomy. I...

Hi, I have been called for an interview for phd in signal processing from an institute which does research in physics and astronomy. I dont know what to expect. ( I guess they will thorougly grill me). I have done masters majoring in DSP and some years of industry experience. I had done my masters thesis in linear predictive coding of speech and wavelets. The work in the industry w...

## Wavelets in vector space without Cauchy-Schwartz inequality

inDear all. I am studying wavelets and multi-resolution analysis (MRA) at the moment. One of the key problems with time-frequency analysis in...

Dear all. I am studying wavelets and multi-resolution analysis (MRA) at the moment. One of the key problems with time-frequency analysis in general is the uncertainty principle with states that the localization in time and in frequency has a lower bound (called Heisenberg boxes in signal processing). My book presents MRA in a Hilbert space (L^2([0;1])) and proves the uncertainty relat...