qsnr8.m

这是求信噪比的程序

clear
rgb=imread('g:\pp.bmp','bmp');
pic=imresize(rgb,[64 64]);
st=zeros(1,4096);
for i=0:63
    for j=0:63
         st(1,i*64+j+1)=pic(i+1,j+1); %str(1,(64*(i-1)+j))=pic(i,j);
   end
end       

aa=wavread('q');
AA=aa';
A(1:40000)=AA(600001:640000);
for i=1:32768 % 4096*8=32768,录音的时候采样频率是22.05KHZ
     Ae(i)=A(i);
end

for k=1:4096
    Aef(k,(1:8))=Ae(((k-1)*8+1):((k-1)*8+8));
    
    y(k,(1:8))=dct(Aef(k,(1:8)));
    
    %yy(k,2)=y(k,2)*(1+8*st(k));
    yy(k,2)=y(k,2)+0.008*st(k);
    yy(k,1)=y(k,1);
    yy(k,(3:8))=y(k,(3:8));
    
    Aee(k,(1:8))=idct( yy(k,(1:8)));
    Aey(1,(((k-1)*8+1):((k-1)*8+8)))=Aee(k,(1:8));
end

for  i=1:32768;%64*64*8=32768录音的时候采样频率是22.05KHZ
     Aw(i)=Aey(i);
end
for i=32769:40000;%64*64*8=32768录音的时候采样频率是22.05KHZ
     Aw(i)=A(i);
end

sa=0;
saw=0;
for p=1:40000
    sa=sa+A(p)^2;%主要这里哦
    saw=saw+(Aw(p)-A(p))^2;
end
if (saw==0) 
    saw=1;
end
s0=sa/saw;
ss1=10*log10(s0);

wavplay(Aw,22050)