matlab练习程序（图像加噪，各种滤波）

cl;

img=imread('3.17.tif');
imgn=imnoise(img,'salt & pepper',0.02);
[m n]=size(img);

%h=fspecial('average',[3 3]);
%
3*3的均值滤波
%imgn1=imfilter(imgn,h,'replicate');

%imgn=medfilt2(imgn,[3 3]);
%
3*3的中值滤波

%%%%自己编写3*3均值滤波
%{
tem=0;
for i=2:1:m-1

for j=2:1:n-1



for p=i-1:1:i+1

for q=j-1:1:j+1

tem=tem+double(imgn(p,q));

end

end


tem=tem/9;

imgn(i,j)=tem;

tem=0;

end
end
%}

%%%%自己编写3*3中值滤波
%{
s=zeros(1,9);
for i=2:1:m-1

for j=2:1:n-1



he=1;

for p=i-1:1:i+1

for q=j-1:1:j+1


s(he)=imgn(p,q);

he=he+1;


end

end


s=sort(s);

imgn(i,j)=s(5);


end
end
%}
imshow(imgn)