ERBLETT ERBlet non-stationary Gabor filterbank
Usage: [c,Ls,g,shift,M] = erblett(f,bins,fs,varargin)
[c,Ls,g,shift] = erblett(...)
[c,Ls] = erblett(...)
c = erblett(...)
Input parameters:
f : The signal to be analyzed (For multichannel
signals, input should be a matrix which each
column storing a channel of the signal)
bins : Desired bins per ERB
fs : Sampling rate of f (in Hz)
varargin : Optional input pairs (see table below)
Output parameters:
c : Transform coefficients (matrix or cell array)
Ls : Original signal length (in samples)
g : Cell array of Fourier transforms of the analysis
windows
shift : Vector of frequency shifts
M : Number of time channels
This function computes an ERBlet constant-Q transform via non-stationary
Gabor filterbanks. Given the signal f, the ERBlet parameter bins,
as well as the sampling rate fs of f, the corresponding ERBlet
coefficients c are given as output. For reconstruction, the length of
f and the filterbank parameters can be returned also.
The transform produces phase-locked coefficients in the
sense that each filter is considered to be centered at
0 and the signal itself is modulated accordingly.
Optional input arguments arguments can be supplied like this:
erblett(f,bins,fs,'Qvar',Qvar)
The arguments must be character strings followed by an
argument:
'Qvar',Qvar Bandwidth variation factor
'M_fac',M_fac Number of time channels are rounded to
multiples of this
'winfun',winfun Filter prototype (see FIRWIN for available
filters)
Examples:
---------
The following example shows analysis and synthesis with ERBLETT and
IERBLETT:
[f,fs] = gspi;
binsPerERB = 4;
[c,Ls,g,shift,M] = erblett(f,binsPerERB,fs);
fr = ierblett(c,g,shift,Ls);
rel_err = norm(f-fr)/norm(f)
plotfilterbank(c,Ls./M,[],fs,'dynrange',60);
References:
T. Necciari, P. Balazs, N. Holighaus, and P. L. Soendergaard. The ERBlet
transform: An auditory-based time-frequency representation with perfect
reconstruction. In Proceedings of the 38th International Conference on
Acoustics, Speech, and Signal Processing (ICASSP 2013), pages 498--502,
Vancouver, Canada, May 2013. IEEE.
Url: http://ltfat.github.io/doc/filterbank/erblett.html
See also: ierblett, firwin.
Package: ltfat