www.pudn.com > spiht-0.3.rar > bldwt9_7.m

function output_signal = bldwt9_7(app_sig,det_sig)  
%  
% output_signal= bldwt9_7(app_sig,det_sig)  
%  
% The back lifting discrete wavelet transform (BLDWT) using the 9-7 Antonini filters  
% Contact me : swf000117@163.com,http://guohanwei.51.net,QQ:461414909 
 
 
[x,y] = size(app_sig);  
if x~=1  
app_sig = app_sig';  
det_sig = det_sig';  
end 
 
tt=length(app_sig); 
 
alp = -1.586134342;  
bet = -0.05298011854;  
gam = 0.8829110762;  
delt = 0.4435068522;  
psi = 1.149604398;  
 
 
d0=det_sig.*psi; 
s0=app_sig./psi; 
 
d0 = [d0(1) d0];  
s0 = s0(1:tt);  
s0 = s0 - delt*(d0(2:length(d0)) + d0(1:length(d0)-1));  
 
 
d0 = d0(2:tt+1);  
s0 = [s0 s0(tt-1)];  
d0 = d0 - gam*(s0(1:length(s0)-1) + s0(2:length(s0)));  
 
 
s0 = s0(1:tt);  
d0 = [d0(1) d0];  
s0 = s0 - bet*(d0(2:length(d0)) + d0(1:length(d0)-1));  
 
s0 = [s0 s0(tt-1)];  
d0 = d0(2:tt+1); 
d0 = d0 - alp*(s0(1:length(s0)-1) + s0(2:length(s0)));  
 
s0=s0(1:tt); 
 
output_signal(1:2:2*tt)=s0;  
output_signal(2:2:2*tt)=d0;  
 
if x~=1  
output_signal=output_signal'; 
end