Divide 256*256 image into 2*2 blocks

I am working on a project of image processing (watermarking) & needs to divide 256*256 image into 2*2 blocks (overlaping) to get 4096 matrices.If anyone knows about it plz help me.

Answer 1

[Walter Roberson]

if ndims(YourArray) == 2
  blocks2x2 = mat2cell(YourArray, 2 * ones(1,128), 2 * ones(1,128) );
else
  blocks2x2 = mat2cell(YourArray, 2 * ones(1,128), 2*ones(1,128), size(YourArray,3) );
end

(Really this can be done with just the second of those assignments without an 'if', but splitting the case permits you to avoid a warning.