CreateBorder

To create a custom border around input data.
... Function - CreateBorder(data_in, H_border, W_border, border_val)
... Creates a border defined by border size around data_in of value = border_val
... For eg -
... >> a = magic(4);
... >> % To create a [2x4] border of 0s around 'a'
... >> a = CreateBorder(a, 2, 4, 0);