cepstrum

(redirected from Quefrency)

cepstrum

[′sep·trəm]
(acoustics)
The Fourier transform of the logarithm of a speech power spectrum; used to separate vocal tract information from pitch excitation in voiced speech.

cepstrum

(mathematics)
(Coined in a 1963 paper by Bogert, Healey, and Tukey) The Fourier transform of the log-magnitude spectrum:

fFt(ln( | fFt(window . signal) | ))

This function is used in speech recognition and possibly elsewhere. Note that the outer transform is NOT an inverse Fourier transform (as reported in many respectable DSP texts).

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References in periodicals archive ?
The idea that started research in the PSF estimation of a blurred image in the cepstral domain was that inherently the cepstrum transforms the multiplication from the frequency domain into a summation in the quefrency (cepstral; reversal of letters from 'frequency') domain.
Second, Cepstral Analysis, which includes Power Cepstrum ([8] Ho, et al 1999 and [9] Randall, et al 1987), Minimum Variance Cepstrum ([10] Choi and Kim 2007) etc., is used for the detection of fault periods in the quefrency domain.
Kim, "Localization of a sound source in a noisy environment by hyperbolic curves in quefrency domain," Journal of Sound and Vibration, vol.
The term "cepstrum" is derived from the english Word "spectrum", the independent variable in the spectral domain is "quefrency".
From the "quefrency" values and the cepstrum, the graphic is posible.
Tukey', Proceedings of the Symposium on Time Series Analysis 1963, The Quefrency Alanysis of Time Series for Echoes: Cepstrum, Pseudo Autocovariance, Cross-Cepstrum and Saphe Cracking, pp.