wavnoise.asv

小波去噪的分解与重构示例

% s=[-1.58 0.42 0.46 0.78 -0.49 0.59 -1.3 -1.42 -0.16 -1.47 -1.35 0.36 -0.44 -0.14 1 -0.5 -0.2 -0.06 -0.6 0.42 -1.52 0.51 0.76 -1.5 0.16 -1.29 -0.65 -1.48 0.6 -1.65 -0.55];
s=load('open.txt');
[C,L]=wavedec(s,1,'db3');
ca1=wrcoef('a',C,L,'db3',1);
x1=ca1 ;
[C,L]=wavedec(s,2,'db3');
ca2=wrcoef('a',C,L,'db3',2);
x2=ca2 ;
[C,L]=wavedec(s,3,'db3');
ca3=wrcoef('a',C,L,'db3',3);
x3=ca3 ;
[C,L]=wavedec(s,4,'db3');
ca4=wrcoef('d',C,L,'db3',3);
x4=ca4 ;
x5=x3+x2+x1;
p=1:length(s);
subplot(6,1,1);plot(p,s);ylabel('原始序列');
subplot(6,1,2);plot(p,x1);ylabel('一层低频信号');
subplot(6,1,3);plot(p,x2);ylabel('二层低频信号');
subplot(6,1,4);plot(p,x3);ylabel('三层低频信号');
subplot(6,1,5);plot(p,x4);ylabel('一层低频信号')
subplot(6,1,6);plot(p,x5);ylabel('信号重构')