DEMO_FILTERBANKSYNCHROSQUEEZE Filterbank synchrosqueezing and inversion The demo shows that the synchrosqueezed filterbank representation can be directly used to reconstruct the original signal. Since we do not work with a filterbank which forms a tight frame (its FILTERBANKRESPONSE is not constant) the direct reconstruction (mere summing all the channels) does not work well. We can fix that by filtering (equalizing) the result by the inverse of the overall analysis filterbank frequency response. Figure 1: ERBlet spectrogram (top) and synchrosqueezed ERBlet spectrogram (bottom) The signal used is the first second from GSPI. Only the energy of the coefficients is show. Both representations are in fact complex and invertible. Figure 2: Errors of the direct and the equalized reconstructions There is still a small DC offset of the signal obtained by the direct summation. References: N. Holighaus, Z. Průša, and P. L. Soendergaard. Reassignment and synchrosqueezing for general time-frequency filter banks, subsampling and processing. Signal Processing, 125:1--8, 2016. [1]http ] References 1. http://www.sciencedirect.com/science/article/pii/S0165168416000141
Url: http://ltfat.github.io/doc/demos/demo_filterbanksynchrosqueeze.html
Package: ltfat