1 clear all;
 2 close all;
 3 clc;
 4 
 5 img=imread('liantong.bmp');
 6 img=img>128;
 7 img=mat2gray(img);
 8 imshow(img);
 9 
10 [m n]=size(img);
11 [x y]=ginput();
12 x=round(x);
13 y=round(y);
14 
15 tmp=ones(m,n);
16 queue_head=1;       %队列头
17 queue_tail=1;       %队列尾
18 neighbour=[-1 -1;-1 0;-1 1;0 -1;0 1;1 -1;1 0;1 1];  %和当前像素坐标相加得到八个邻域坐标
19 %neighbour=[-1 0;1 0;0 1;0 -1];     %四邻域用的
20 q{queue_tail}=[y x];
21 queue_tail=queue_tail+1;
22 [ser1 ser2]=size(neighbour);
23 
24 while queue_head~=queue_tail
25     pix=q{queue_head};
26     for i=1:ser1
27         pix1=pix+neighbour(i,:);
28         if pix1(1)>=1 && pix1(2)>=1 &&pix1(1)<=m && pix1(2)<=n
29             if img(pix1(1),pix1(2))==1 
30                 img(pix1(1),pix1(2))=0;
31                 q{queue_tail}=[pix1(1) pix1(2)];
32                 queue_tail=queue_tail+1;
33 
34             end      
35         end
36     end
37 
38     queue_head=queue_head+1;
39 end
40 
41 figure(1);
42 imshow(mat2gray(img));