bldwt9_7.m

SPIHT的MATLAB源代码,希望对有需要的朋友有所帮助.

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 
[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