Re: Wavelets

sanindland wrote:
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.

"Noise" is a very general term. I guess since you are interested in
locality, you are looking for short bursts of "outliers" (clicks,
transients). Just recently, somebody posted this link, which might be
helpful for detection of such events:

"Detection of Abrupt Changes"
http://www.irisa.fr/sisthem/k***/

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 with different types of Wavelets(Daubechies,
Morlet,....) using Mallat's algorithm using Visual Basic. I got struck
while I want to use these real time signals as input arrays in my
equations. On analysing these factors I have decided in buying Wavelet &
Signal processing extension Package for Mathcad (However, buying Matlab is
not an option in my case).

Can anyone help me with ideas/ suggestions/ just direct me in the right
path

To be more specific, you have to write more about what kind of "noises"
you are looking for, and in what kind of "signals" they are embedded
in. Detection via DWT is just one of many feasible paths. Sometimes,
much simpler methods are adequate.

Regards,
Andor

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