1 cl;
 2 
 3 img=imread(\'3.17.tif\');
 4 imgn=imnoise(img,\'salt & pepper\',0.02);
 5 [m n]=size(img);
 6 
 7 %h=fspecial(\'average\',[3 3]);    %   3*3的均值滤波
 8 %imgn1=imfilter(imgn,h,\'replicate\');
 9 
10 %imgn=medfilt2(imgn,[3 3]);     %    3*3的中值滤波
11 
12 %%%%自己编写3*3均值滤波
13 %{
14 tem=0;
15 for i=2:1:m-1
16     for j=2:1:n-1     
17    
18         for p=i-1:1:i+1
19             for q=j-1:1:j+1
20                 tem=tem+double(imgn(p,q));
21             end
22         end
23 
24         tem=tem/9;
25         imgn(i,j)=tem;
26         tem=0;
27     end
28 end
29 %}
30 
31 %%%%自己编写3*3中值滤波
32 %{
33 s=zeros(1,9);
34 for i=2:1:m-1
35     for j=2:1:n-1     
36         
37         he=1;
38         for p=i-1:1:i+1
39             for q=j-1:1:j+1            
40                 s(he)=imgn(p,q);
41                 he=he+1;               
42             end
43         end
44 
45         s=sort(s);
46         imgn(i,j)=s(5);
47         
48     end
49 end
50 %}
51 imshow(imgn)