How can I make diamond shape with a matrix?

I want to make diamond image with a matrix

ex. background image is zeros(1000,1000)

from center, make this matrix [1 2 ; 3 4] like a diamond..

.

.

.

0 0 1 2 0 0...

0 0 3 4 0 0

1 2 1 2 1 2

3 4 3 4 3 4

0 0 1 2 0 0

0 0 3 4 0 0 ...

.

.

.

plz help me.. thanks!!

Answer 1

[Stephen23]

Without the image toolbox:

>> N = 5;
>> V = round((N:-1:1)/(N+1));
>> M = toeplitz(V);
>> M = M & rot90(M)
M =
   0   0   1   0   0
   0   1   1   1   0
   1   1   1   1   1
   0   1   1   1   0
   0   0   1   0   0
>> kron(M,[1,2;3,4])
ans =
   0   0   0   0   1   2   0   0   0   0
   0   0   0   0   3   4   0   0   0   0
   0   0   1   2   1   2   1   2   0   0
   0   0   3   4   3   4   3   4   0   0
   1   2   1   2   1   2   1   2   1   2
   3   4   3   4   3   4   3   4   3   4
   0   0   1   2   1   2   1   2   0   0
   0   0   3   4   3   4   3   4   0   0
   0   0   0   0   1   2   0   0   0   0
   0   0   0   0   3   4   0   0   0   0

Answer 2

[Andrei Bobrov]

a = strel('diamond',250);
out = kron(a.Neighborhood,[1 2 ; 3 4]);

[Andrei Bobrov]

I'm fixed typo.

Answer 3

[Akira Agata]

How about the following?

N = 5; % <- Should be odd number
A = repmat([1 2;3 4],N);
se = strel('diamond',floor(N/2));
idx = imresize(se.Neighborhood,2);
A(~idx) = 0;

>> A

A =

0 0 0 0 1 2 0 0 0 0

0 0 0 0 3 4 0 0 0 0

0 0 1 2 1 2 1 2 0 0

0 0 3 4 3 4 3 4 0 0

1 2 1 2 1 2 1 2 1 2

3 4 3 4 3 4 3 4 3 4

0 0 1 2 1 2 1 2 0 0

0 0 3 4 3 4 3 4 0 0

0 0 0 0 1 2 0 0 0 0

0 0 0 0 3 4 0 0 0 0