i=imread('222.bmp')
[m,n]=size(i)
index=1;
for t1=1:m
    for t2=1:n
        if i(t1,t2)>0;
            x(index)=t1;
            y(index)=t2;
            index=index+1;
            
        end
    end
end
x11=floor(sum(x)/(index-1));
y11=floor(sum(y)/(index-1));
p=1;
w=zeros(index-1,2);
for t1=1:m;
    for t2=1:n;
        if i(t1,t2)>0;
             w(p,:)=[t1 t2];
             p=p+1;
         end
     end
 end
x1=max(x);
x2=min(x);
y1=max(y);
y2=min(y);
for k=x2:x1;
   i(k,y2)=255;
    i(k,y1)=255;
end
for k=y2:y1;
  i(x2,k)=255;
   i(x1,k)=255;
end
subplot(1,2,1);
figure(1);
imshow(i)