Time-Frequency Reassignment

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 [12,71,78]. The basic idea is to refine the spectrogram (§6.2) 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.

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About the Author: Julius Orion Smith III
Julius Smith's background is in electrical engineering (BS Rice 1975, PhD Stanford 1983). He is presently Professor of Music and Associate Professor (by courtesy) of Electrical Engineering at Stanford's Center for Computer Research in Music and Acoustics (CCRMA), teaching courses and pursuing research related to signal processing applied to music and audio systems. See http://ccrma.stanford.edu/~jos/ for details.