how do we divide and recombine image into blocks?

I have already divided image into blocks using the following code;

Block(:,:,kk+j)=odd((bs*(i-1)+1:bs*(i-1)+bs),(bs*(j-1)+1:bs*(j-1)+bs));

now how do i recombine back?

[harjeet singh]

kindly upload the full code with i and j loop