小波去噪matlab程序.doc

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1、[转帖]小波去噪matlab程序******************************************clearclc%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);fori=1:count1signal(i)=sound(i);endfori=1:count1y(i)=signal(i)+noise(i);end%在小波基'db3'下进行一维离散小波变换[coefs1,co

2、efs2]=dwt(y,'db3');%[低频高频]count2=length(coefs1);count3=length(coefs2);energy1=sum((abs(coefs1)).^2);energy2=sum((abs(coefs2)).^2);energy3=energy1+energy2;fori=1:count2recoefs1(i)=coefs1(i)/energy3;endfori=1:count3recoefs2(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(co

3、unt2/zhen);fori=1:count4n=160*(i-1)+1:160+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（unvoice）时，输出为1；为浊音（voice）时，输出为0ifcorr>=0.8output1(i)=0;elseifcorr<=0.1output1(i)=1;endendfori=1:count4n=160*(i-1)+

4、1:160+160*(i-1);ifoutput1(i)==1switchabs(recoefs1(i))caseabs(recoefs1(i))<=0.002recoefs1(i)=0;caseabs(recoefs1(i))>0.002&abs(recoefs1(i))<=0.003recoefs1(i)=sgn(recoefs1(i))*(0.003*abs(recoefs1(i))-0.000003)/0.002;otherwiserecoefs1(i)=recoefs1(i);endelseifoutput1(i)==0recoefs1(i)=recoe

5、fs1(i);endend%对高频系数进行语音信号清浊音的判别count5=fix(count3/zhen);fori=1:count5n=160*(i-1)+1:160+160*(i-1);s=sound(n);w=hamming(160);sw=s.*w;a=aryule(sw,10);sw=filter(a,1,sw);sw=sw/sum(sw);r=xcorr(sw,'biased');corr=max(r);%为清音（unvoice）时，输出为1；为浊音（voice）时，输出为0ifcorr>=0.8output2(i)=0;elseifcorr<=0.

6、1output2(i)=1;endendfori=1:count5n=160*(i-1)+1:160+160*(i-1);ifoutput2(i)==1switchabs(recoefs2(i))caseabs(recoefs2(i))<=0.002recoefs2(i)=0;caseabs(recoefs2(i))>0.002&abs(recoefs2(i))<=0.003recoefs2(i)=sgn(recoefs2(i))*(0.003*abs(recoefs2(i))-0.000003)/0.002;otherwiserecoefs2(i)=recoef

7、s2(i);endelseifoutput2(i)==0recoefs2(i)=recoefs2(i);endend%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');