Fast Signal Reconstruction from
Magnitude Spectrogram of Continuous Wavelet Transform based on Spectrogram Consistency

Contributors:
Tomohiko Nakamura (The University of Tokyo) and Hirokazu Kameoka (The
University of Tokyo/NTT Communication Science laboratories).

Demonstration of signal reconstruction

You will be aware of reconstructing the signal as same as the original signal iteration by iteration.

Original acoustic signal

Magnitude CWT spectrogram with random phases

Estimation results by the proposed algorithm

After 1 iterations

After 10 iterations

After 20 iterations

After 50 iterations

After 100 iterations

Demonstration of pitch tranposition

You can see that only shifting the complex CWT spectrogram is not enough to obtain the pitch-transposed signals, and the pitch transposition is realized by the proposed phase estimation.

Original acoustic signal

Shifting complex CWT spectrogram

Shifting magnitude CWT spectrogram and zero phases

Shifting magnitude CWT spectrogram and estimated phases