Morphological operations on a binary image

clc;clear all;close all;
img = imread('circles.png');
id  = double(img);
[row col] = size(id);
SE = [1 1 1;1 1 1;1 1 1];
 
for i = 2:1:row-1
    for j = 2:1:col-1
        array = [SE(1)*id(i-1,j-1) , SE(2)*id(i-1,j) , SE(3)*id(i-1,j+1) , SE(4)*id(i,j-1) , SE(5)*id(i,j) , SE(6)*id(i,j+1) , SE(7)*id(i+1,j-1) , SE(8)*id(i+1,j) , SE(9)*id(i+1,j+1)];
        dil(i,j) = max(array);
        ero(i,j) = min(array);
        
    end
end
 
for i = 2:1:row-2
    for j = 2:1:col-2
        oparray = [SE(1)*ero(i-1,j-1) , SE(2)*ero(i-1,j) , SE(3)*ero(i-1,j+1) , SE(4)*ero(i,j-1) , SE(5)*ero(i,j) , SE(6)*ero(i,j+1) , SE(7)*ero(i+1,j-1) , SE(8)*ero(i+1,j) , SE(9)*ero(i+1,j+1)];
        op(i,j) = max(oparray);
        closearray = [SE(1)*dil(i-1,j-1) , SE(2)*dil(i-1,j) , SE(3)*dil(i-1,j+1) , SE(4)*dil(i,j-1) , SE(5)*dil(i,j) , SE(6)*dil(i,j+1) , SE(7)*dil(i+1,j-1) , SE(8)*dil(i+1,j) , SE(9)*dil(i+1,j+1)];
        clos(i,j) = min(closearray);
       end
end
figure;
subplot(2,2,1),imshow(id);title('original image');
subplot(2,2,2),imshow(dil);title('dilated image');
subplot(2,2,3),imshow(id);title('original image');
subplot(2,2,4),imshow(ero);title('eroded image');
 
figure;
subplot(2,2,1),imshow(id);title('original image');
subplot(2,2,2),imshow(op);title('opening image');
subplot(2,2,3),imshow(id);title('original image');
subplot(2,2,4),imshow(clos);title('closing image');