f=idtwfb(c,info); f=idtwfb(c,dualwt,Ls);
| c | Input coefficients. |
| info | Transform params. struct |
| dualwt | Dual-tree Wavelet Filterbank definition |
| Ls | Length of the reconstructed signal. |
| f | Reconstructed data. |
f = idtwfb(c,info) reconstructs signal f from the coefficients c using parameters from info struct. both returned by dtwfb function.
f = idtwfb(c,dualwt,Ls) reconstructs signal f from the coefficients c using dual-tree filterbank defined by dualwt. Plese see dtwfb for supported formats. The Ls parameter is mandatory due to the ambiguity of reconstruction lengths introduced by the subsampling operation. Note that the same flag as in the dtwfb function have to be used, otherwise perfect reconstruction cannot be obtained. Please see help for dtwfb for description of the flags.
A simple example showing perfect reconstruction using idtwfb:
f = gspi;
J = 7;
wtdef = {'qshift3',J};
c = dtwfb(f,wtdef);
fhat = idtwfb(c,wtdef,length(f));
% The following should give (almost) zero
norm(f-fhat)