文档介绍:clcI=imread('C:\DocumentsandSettings\Administrator\×à??\');figureimshow(I)title('?-í?')J=imnoise(I,'salt&pepper',);figureimshow(J)title('o???éùí???')[p,q]=size(J);x=double(J);n=1;fori=2:p-1forj=2:q-1forn=1:4shang=i-n;xia=i+n;ifshang<1shang=i;elseifxia>pxia=i;endzuo=j-n;you=j+n;ifzuo<1zuo=j;elseifyou>qyou=j;endc=x(shang:xia,zuo:you);smax=max(max(c));smm=median(median(c));smin=min(min(c));NS=c((x(i,j)>smin)&(x(i,j)<smax));iflength(NS)~=0smns=median(median(NS));if(x(i,j)>=smax)|(x(i,j)<=smin)x(i,j)=smns;endelsen=n+1;endifn>4x(i,j)=smm;endendendendy=uint8(x);figure,imshow(y),title('è¥??oóμ?í???')y=double(y);I=double(I);[p,q]=size(y);MSE=0;s=0;fori=1:pforj=1:qMSE=MSE+(y(i,j)-I(i,j)).^2;s=s+(I(i,j)).^2;endendNMSE=MSE/sPSNR=10*log10(((255*255*p*q))/MSE)==========