I = imread('eight.tif');
J = imnoise(I,'salt & pepper',0.02);
%圖像添加鹽椒噪聲
domain=[0 0 1 0 0;
        0 1 0 1 0;
        1 0 1 0 1;
        0 1 0 1 0;
        0 0 1 0 0];
K = ordfilt2(J,1,domain);
%3×3鄰域窗的最小值濾波
subplot(121),imshow(J)
title('添加鹽椒噪聲圖像')
subplot(122),imshow(K)
title('3×3鄰域窗的最小值濾波圖像')