Matlab Program for Boundary Detection

close all; 
clear all; 
BW1 = imread('xxx.jpg'); 
subplot(1,2,1); 
imshow(BW1) title('original image'); 
SE = strel('arbitrary',eye(5));
BW2 = imerode(BW1,SE); 
subplot(1,2,2); 
imshow(BW1 - BW2) title('Boundary Extracted');