fldwt9_7.m

来自「SPIHT的MATLAB源代码,希望对有需要的朋友有所帮助.」· M 代码 · 共 45 行

function [app_sig,det_sig] = fldwt9_7(input_signal) 
% Function 
% [app_sig,det_sig] = fldwt9_7(input_signal) 
% 
% The forward lifting discrete wavelet transform (FLDWT) using the 9-7 Antonini filters 

[x,y] = size(input_signal); 

if x ~=1 
input_signal = input_signal'; % making it a row vector 
end 

alp = -1.586134342; 
bet = -0.05298011854; 
gam = 0.8829110762; 
delt = 0.4435068522; 
psi = 1.149604398; 

s0 = input_signal(1:2:length(input_signal)); 
d0 = input_signal(2:2:length(input_signal)); 
tt = length(s0); 

s0 = [s0 s0(tt-1)]; 
d0 = d0 + alp*(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)); 

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 + delt*(d0(2:length(d0)) + d0(1:length(d0)-1)); 

d0 = d0(2:tt+1); 
app_sig = psi*s0; 
det_sig = (1/psi)*d0; 

if x~=1 
app_sig = app_sig'; 
det_sig = det_sig'; 
end