Q:

Erosion in image

I don't if I am posting my question in the correct place.  I have tried hard to solved it but I am unsuccessful.
I have an structuring element shown below:
1 1 1
1 1 1
1 1 1

My image is:
11   11
11   11
11   11
11   11
1111111
11   11
11   11
11   11
11   11
11   11

I have to apply erosion using the above image and structuring element (It is not programming, it is a question from exam paper).  When I apply the structuring element on the image, I found that the overall image disappear.
Please help me. Kindly please note that I am new here and I don't know if I can place this question here.
Thank you.

A:

You are correct.  Erosion of that image with that structuring element should cause all of the 1's to disappear.
There are two ways to look at it.  One is that only ones that are surrounded by ones will remain.  There are no such ones.  The other is that you will only have ones remain where you can fit the structure element into a set of ones in the image, and there is no such place.

