gd=nsgabdual(g,a,M); gd=nsgabdual(g,a,M,L);
| g | Cell array of windows. |
| a | Vector of time shift. |
| M | Vector of numbers of channels. |
| L | Transform length. |
| gd | Cell array of canonical dual windows |
nsgabdual(g,a,M,L) computes the canonical dual windows of the non-stationary discrete Gabor frame defined by windows given in g an time-shifts given by a.
nsgabdual is designed to be used with the functions nsdgt and insdgt. See the help on nsdgt for more details about the variables structure.
The computed dual windows are only valid for the 'painless case', that is to say that they ensure perfect reconstruction only if for each window the number of frequency channels used for computation of nsdgt is greater than or equal to the window length. This correspond to cases for which the frame operator is diagonal.
P. Balazs, M. Dörfler, F. Jaillet, N. Holighaus, and G. A. Velasco. Theory, implementation and applications of nonstationary Gabor frames. J. Comput. Appl. Math., 236(6):1481--1496, 2011. [ .pdf ]