I = imread('test1.bmp'); 
figure, imshow(I), 
BW1 = im2bw(I); %一般輸入的圖像是彩色的，需要轉成黑白的
se90 = strel('line', 3, 90);%線，長度為3，角度為90度
se0 = strel('line', 3, 0); %線，長度為3，角度為0度
BW2= imdilate(BW1, [se90 se0]);
figure, imshow(BW2);
BW3 = imerode(BW1,[se90 se0]);
figure, imshow(BW3);