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Scalogram in Matlab with DWT

  1. Jul 18, 2009 #1

    In Matlab I can calculated the the Spectrogram of an
    Audio signal with the Short Time Fourier Transformation
    which uses the the Discrete Fourier Transformation (FFT).

    I can do the same thing using the Wavelet Transformation
    by using in Matlab the continuous wavelet Transformation CWT
    and display me a Scalogram. Which gets explained here

    http://kelvinchufei.blogspot.com/2008/01/wavelet-scalogram-using-complex-morlet.html" [Broken]

    But this is very slow.

    How can I do this with the discrete Wavelet Transformation.
    Should I not get an equal result, since the discrete FT in the STFT
    gives me also a good result.

    I tried to use the "wavedec" function by splitting up the
    Signals into frames in the same way the STFT gets calutated
    But the result comes not even close to the image I get with the cwt.
    Is it because of the scaling Interval of 2^x for the DWT?
    Last edited by a moderator: May 4, 2017
  2. jcsd
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