小波去噪matlab程序.doc

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);for i=1:count1signal(i)=sound(i);endfor i=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,coefs2=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;for i=1:count2recoefs1(i)=coefs1(i)/energy3;endfor i=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(count2/zhen);for i=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);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0if corr=0.8output1(i)=0;elseif corr=0.1output1(i)=1;endendfor i=1:count4n=160*(i-1)+1:160+160*(i-1);if output1(i)=1switch abs(recoefs1(i)case abs(recoefs1(i)0.002 & abs(recoefs1(i)=0.8output2(i)=0;elseif corr=0.1output2(i)=1;endendfor i=1:count5n=160*(i-1)+1:160+160*(i-1);if output2(i)=1switch abs(recoefs2(i)case abs(recoefs2(i)0.002 & abs(recoefs2(i)=0.003recoefs2(i)=sgn(recoefs2(i)*(0.003*abs(recoefs2(i)-0.000003)/0.002;otherwise recoefs2(i)=recoefs2(i);endelseif output2(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.wavwavwr