borders of simple image

I have this image, ploted with pcolor:

How come that if i want to plot only borders it doesnt work?

bwmorph(Im,'remove')

The border on the top is missing...

Answer 1

[Image Analyst]

pcolor() does not display the entire image. This is a known "feature" that I've been warning people about for years. Notice that you have only 19 by 19 pixels, not 20x20. Use imshow() instead. I recommend never using pcolor to look at regular, normal, rectangular images.

Answer 2

[Sean de Wolski]

Can you please provide full reproduction steps? Repeating these steps below does not reproduce this behavior:

SE = strel('disk',10);
BW = SE.getnhood; 
subplot(121)
imshow(BW);
BWr = bwmorph(BW,'remove');
subplot(122)
imshow(BWr)