ifwt   

 ifwt.m

 Inverse fast wavelet transform.

 Usage: x = ifwt(w, g0, g1, J, sym);
 w - nx1 input vector of wavelet coeffients
 g0 - lowpass reconstruction filter
 g1 - highpass reconstruction filter
      g0 and g1 should be zero padded appropriately so that they have the
      same length, and this length is even.
 J - number of levels in the filter bank.
     Right now, it must be chose so that n*2^(-J) >= length(g0)
 sym - How the input was extended when the forward transform was taken.
     sym=0: periodization
     sym=1: type-I symmetric extension ( [... x(2) x(1) x(2) x(3) ...])
            The wavelet filters must have type-I even symmetry 
            (e.g. daub79)
     sym=2: type-II symmetric extension ( [... x(2) x(1) x(1) x(2) x(3) ...])
            The lowpass filter must have type-II even symmetry, 
            The highpass filter must have type-II odd symmetry.
            (e.g. daub1018)

 Written by: Justin Romberg
 Created: April 2007

0001 % ifwt.m
0002 %
0003 % Inverse fast wavelet transform.
0004 %
0005 % Usage: x = ifwt(w, g0, g1, J, sym);
0006 % w - nx1 input vector of wavelet coeffients
0007 % g0 - lowpass reconstruction filter
0008 % g1 - highpass reconstruction filter
0009 %      g0 and g1 should be zero padded appropriately so that they have the
0010 %      same length, and this length is even.
0011 % J - number of levels in the filter bank.
0012 %     Right now, it must be chose so that n*2^(-J) >= length(g0)
0013 % sym - How the input was extended when the forward transform was taken.
0014 %     sym=0: periodization
0015 %     sym=1: type-I symmetric extension ( [... x(2) x(1) x(2) x(3) ...])
0016 %            The wavelet filters must have type-I even symmetry
0017 %            (e.g. daub79)
0018 %     sym=2: type-II symmetric extension ( [... x(2) x(1) x(1) x(2) x(3) ...])
0019 %            The lowpass filter must have type-II even symmetry,
0020 %            The highpass filter must have type-II odd symmetry.
0021 %            (e.g. daub1018)
0022 %
0023 % Written by: Justin Romberg
0024 % Created: April 2007