afwt2   

 afwt2.m

 Adjoint of fwt2

 Usage: x = afwt2(w, h0, h1, J, sym);
 x - mxn output image (min(m,n) must be divisible by 2^J) 
 w - mxn input image of wavelet coeffients
 h0 - lowpass decomposition filter
 h1 - highpass decomposition filter
      h0 and h1 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 chosen so that n*2^(-J) >= length(h0)
 sym - How to extend the input.
     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)

0001 % afwt2.m
0002 %
0003 % Adjoint of fwt2
0004 %
0005 % Usage: x = afwt2(w, h0, h1, J, sym);
0006 % x - mxn output image (min(m,n) must be divisible by 2^J)
0007 % w - mxn input image of wavelet coeffients
0008 % h0 - lowpass decomposition filter
0009 % h1 - highpass decomposition filter
0010 %      h0 and h1 should be zero padded appropriately so that they have the
0011 %      same length, and this length is even.
0012 % J - number of levels in the filter bank.
0013 %     Right now, it must be chosen so that n*2^(-J) >= length(h0)
0014 % sym - How to extend the input.
0015 %     sym=0: periodization
0016 %     sym=1: type-I symmetric extension ( [... x(2) x(1) x(2) x(3) ...])
0017 %            The wavelet filters must have type-I even symmetry
0018 %            (e.g. daub79)
0019 %     sym=2: type-II symmetric extension ( [... x(2) x(1) x(1) x(2) x(3) ...])
0020 %            The lowpass filter must have type-II even symmetry,
0021 %            The highpass filter must have type-II odd symmetry.
0022 %            (e.g. daub1018)
0023 %
0024 
0025 %
0026 % Written by: Justin Romberg
0027 % Created: April 2007