Spatial filtering in image processing

Clc
I=imread('cameraman.tif');
[m n]=size(I);
a=im2double(I);
for i=1:m-2
    for j=1:n-2
          v(i,j) = [a(i,j) + a(i,j+1) + a(i,j+2) + a(i+1,j) + a(i+1,j+1) + a(i+1,j+2) + a(i+2,j) +  a(i+2,j+1) +     a(i+2,j+2)]./9;    %smoothing filter
 
x(i,j) = [0*a(i,j) + 1*a(i,j+1) + 0*a(i,j+2) + 1*a(i+1,j) + -4*a(i+1,j+1) + 1*a(i+1,j+2) + 0*a(i+2,j) + 1*a(i+2,j+1) + 0*a(i+2,j+2)];   %high pass filter
 
w(i,j) = [1*a(i,j) + 1*a(i,j+1) + 1*a(i,j+2) + 1*a(i+1,j) + -8*a(i+1,j+1) + 1*a(i+1,j+2) + 1*a(i+2,j) + 1*a(i+2,j+1)  + 1*a(i+2,j+2)];   %high boost filter 
 
array = [a(i,j),a(i,j+1),a(i,j+2),a(i+1,j),a(i+1,j+1),a(i+1,j+2),a(i+2,j),a(i+2,j+1),a(i+2,j+2)];
          arr(i,j)=median(array);               %median filter
 
y(i,j)=min(array);                  %minimum filter
 
z(i,j)=max(array);                  %maximum filter
 
       end;
end;
figure;imshow(I);
title('Original image');
figure;imshow(v);
title('Image after Low pass filtering (smoothing)');
figure;imshow(x);
title('Image after high pass filtering');
figure;imshow(w);
title('Image after high boost filtering');
figure;imshow(arr);
title('Image after median filtering');
figure;imshow(y);
title('Image after minimum filtering');
figure;imshow(z);
title('Image after maximum filtering');