Copyright © 2022-02-28 by Julius O. Smith III
Center for Computer Research in Music and Acoustics (CCRMA), Stanford University
A relatively recent topic in sinusoidal modeling is time-frequency reassignment, in which STFT phase information is used to provide nonlinearly enhanced time-frequency resolution in STFT displays [12,73,81]. The basic idea is to refine the spectrogram (§7.2) by assigning spectral energy in each bin to its ``center of gravity'' frequency instead of the bin center frequency. This has the effect of significantly sharpening the appearance of spectrograms for certain classes of signals, such as quasi-sinusoidal sums. In addition to frequency reassignment, time reassignment is analogous.