function wc = FWT3_PO(x,L,qmf)
% FWT3_PO -- 3-d MRA wavelet transform (periodized, orthogonal)
%  Usage
%    wc = FWT3_PO(x,L,qmf)
%  Inputs
%    x     3-d object (n by n by n array, n dyadic)
%    L     coarse level
%    qmf   quadrature mirror filter
%  Outputs
%    wc    3-d wavelet transform
%
%  Description
%    A three-dimensional Wavelet Transform is computed for the
%    array x.  To reconstruct, use IWT3_PO.
%
%  See Also
%    IWT3_PO, MakeONFilter
%
	[n,J] = cubelength(x);
	wc = x; 
	nc = n;
	for jscal=J-1:-1:L,
		top = (nc/2+1):nc;    bot = 1:(nc/2);
		for ix=1:nc,
            for iy = 1:nc,
			row = wc(ix,iy,1:nc);
              rowsq=squeeze(row)';
			wc(ix,iy,bot) = DownDyadLo(rowsq,qmf)';
			wc(ix,iy,top) = DownDyadHi(rowsq,qmf)';
            end
		end
        %----------------------------------------
       for ix=1:nc,
            for iz = 1:nc,
			row = wc(ix,1:nc,iz);
			wc(ix,top,iz) = DownDyadHi(row,qmf);
			wc(ix,bot,iz) = DownDyadLo(row,qmf); 
          end
	   end    
        %----------------------------------------
		for iy=1:nc,
            for iz = 1:nc,
			row = wc(1:nc,iy,iz)';
			wc(top,iy,iz) = DownDyadHi(row,qmf)';
			wc(bot,iy,iz) = DownDyadLo(row,qmf)'; 
            end
	   end	
       %-----------------------------------------
 	 nc = nc/2;
	end   
 
% 
% Copyright (c) 1993. David L. Donoho
%     
% 3-D Modification Vicki Yang and Brani Vidakovic
%                  ISyE, GaTech 2002.