AM-FM Demodulation of Spectrograms using 2-D Max-Gabor Analysis

Ezzat T., Bouvrie J., Poggio T.,

32nd IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP2007) , , Honolulu, Hawaii , 2007

Abstract: We present a method that de-modulates a narrowband magnitude spectrogram S(f, t) into a frequency modulation term cos(ø (f, t)) which represents the underlying harmonic carrier, and an amplitude modulation term A(f, t) which represents the spectral envelope. Our method operates by performing a two-dimensional local patch analysis of the spectrogram, in which each patch is factored into a local carrier term and a local amplitude envelope term using a Max-Gabor analysis. We demonstrate the technique over a wide variety of speakers, and show how the spectrograms in each case may be adequately reconstructed as S(f, t) = A(f, t)cos(ø (f, t)).

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