小波去噪matlab程序.docx

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1、小波去噪matlab程序转帖小波去噪matlab程序 * clear clc %在噪声环境下语音信号的增强 %语音信号为读入的声音文件 %噪声为正态随机噪声 sound=wavread(c12345.wav); count1=length(sound); noise=0.05*randn(1,count1); for i=1:count1 signal(i)=sound(i); end for i=1:count1 y(i)=signal(i)+noise(i); end %在小波基db3下进行一维离散小波变换 coefs1,coefs2=dwt(y,db3); %低频 高频 count2=l

2、ength(coefs1); count3=length(coefs2); energy1=sum(abs(coefs1).2); energy2=sum(abs(coefs2).2); energy3=energy1+energy2; for i=1:count2 recoefs1(i)=coefs1(i)/energy3; end for i=1:count3 recoefs2(i)=coefs2(i)/energy3; end %低频系数进行语音信号清浊音的判别 zhen=160; count4=fix(count2/zhen); for i=1:count4 n=160*(i-1)+1

3、:160+160*(i-1); s=sound(n); w=hamming(160); sw=s.*w; a=aryule(sw,10); sw=filter(a,1,sw); w=sw/sum(sw); r=xcorr(sw,biased); corr=max(r); %为清音时，输出为1；为浊音时，输出为0 if corr=0.8 output1(i)=0; elseif corr=0.1 output1(i)=1; end end for i=1:count4 n=160*(i-1)+1:160+160*(i-1); if output1(i)=1 switch abs(recoefs1

4、(i) case abs(recoefs1(i)0.002 & abs(recoefs1(i)=0.8 output2(i)=0; elseif corr=0.1 output2(i)=1; end end for i=1:count5 n=160*(i-1)+1:160+160*(i-1); if output2(i)=1 switch abs(recoefs2(i) case abs(recoefs2(i)0.002 & abs(recoefs2(i)=0.003 recoefs2(i)=sgn(recoefs2(i)*(0.003*abs(recoefs2(i)-0.000003)/0.

5、002; otherwise recoefs2(i)=recoefs2(i); end elseif output2(i)=0 recoefs2(i)=recoefs2(i); end end %在小波基db3下进行一维离散小波反变换 output3=idwt(recoefs1, recoefs2,db3); %对输出信号抽样点值进行归一化处理 maxdata=max(output3); output4=output3/maxdata; %读出带噪语音信号，存为101.wav wavwrite(y,5500,16,c101); %读出处理后语音信号，存为102.wav wavwrite(output4,5500,16,c102);