www.pudn.com > multiwavelet.rar > prep2D_rr.m

function fp=prep2D_rr(f,flt) 
%fp=prep2D_rr(f,flt)  
% 
%  This function performs oversampled ("repeated row") preprocessing of  
%  given 2-dimensional signal. For description of the algorithm see [SW]. 
% 
%  Input: 
%    flt        string of characters, name of the filter to be used; 
%               for possible names and short descriptions see coef.m  
%    f          n by n real array, input signal;//2-D输入信号 
% 
%    n          n must be of the form integer*2^maxlevel,//信号的长度 
%    maxlevel   maxlevel is the number of levels of multiwavelet decomposition //多小波分解的层数 
% 
%  Output:  
%    fp         n by n real array, preprocessed signal; 
%               for structure of fp see [SW] 
% 
%  Example of Usage 
%    fp=prep2D_rr(f,'cl')  
 
% Author: Vasily Strela 
% COPYRIGHT 1997,98 by Vasily Strela 
 
[L,H]=coef(flt); 
[n1,n2]=size(f); 
[nf,ns]=size(L); 
ns=ns/nf; 
fp=zeros(nf*n1,nf*n2); 
 
H0=zeros(nf); 
for i=1:ns 
  H0=H0+L(:,nf*(i-1)+1:nf*i); 
end 
[V,D]=eig(H0'/(sqrt(2))); 
fl=0; 
for i=1:nf 
  if abs(D(i,i)-1.)<0.000001 
    fl=i; 
  end 
end 
a0=V(:,fl); 
big=0; 
for i=1:nf 
  if abs(a0(i))>abs(big) 
    big=a0(i); 
  end 
end 
for i=1:nf 
  a0(i)=a0(i)/big; 
end 
 
for i=1:n1 
  for j=1:nf 
    fp(i,(j-1)*n2+1:j*n2)=a0(j)*f(i,:); 
  end 
end 
 
aa=fp(1:n1,:); 
for i=1:n2*nf 
  for j=1:nf 
    fp((j-1)*n1+1:j*n1,i)=a0(j)*aa(:,i); 
  end 
end