[tgrad,fgrad,s,c] = filterbankphasegrad(f,g,a,L,minlvl); [tgrad,fgrad,s,c] = filterbankphasegrad(f,g,a,L); [tgrad,fgrad,s,c] = filterbankphasegrad(f,g,a,minlvl); [tgrad,fgrad,s,c] = filterbankphasegrad(f,g,a); [tgrad,fgrad,s] = filterbankphasegrad(...) [tgrad,fgrad] = filterbankphasegrad(...)
| f | Signal to be analyzed. |
| g | Cell array of filters |
| a | Vector of time steps. |
| L | Signal length (optional). |
| minlvl | Regularization parameter (optional, required < 1). |
| tgrad | Instantaneous frequency relative to original position. |
| fgrad | The negative of the local group delay. |
| cs | Filterbank spectrogram. |
| c | Filterbank coefficients. |
[tgrad,fgrad,s,c] = filterbankphasegrad(f,g,a,L) computes the relative instantaneous frequency tgrad and the negative of the group delay fgrad of the filterbank spectrogram s obtained from the signal f and filterbank parameters g and a. Both tgrad and fgrad are specified relative to the original coefficient position entirely similar to gabphasegrad. fgrad is given in samples, while tgrad is given in normalised frequencies such that the absolute frequencies are in the range of ]-1,1].
This routine uses the equivalence of the filterbank coefficients in each channel with coefficients obtained from an STFT obtained with a certain window (possibly different for every channel). As a consequence of this equivalence, the formulas derived in the reference apply.
F. Auger and P. Flandrin. Improving the readability of time-frequency and time-scale representations by the reassignment method. IEEE Trans. Signal Process., 43(5):1068--1089, 1995.
N. Holighaus, Z. Průša, and P. L. Søndergaard. Reassignment and synchrosqueezing for general time-frequency filter banks, subsampling and processing. Signal Processing, 125:1--8, 2016. [ DOI | http ]