title: divide the image into 3*3 blocks
body: <p>I have a matrix that does not happen to have dimensions that are multiples of 3 or it might.
  How can we divide the entire image into blocks of 3*3 matrices.
  (Can ignore the last ones which does not come under the 3*3 multiples.
  Also, the 3*3 matrices can be be saved in arrays.</p>
  
  <pre><code>a=3; b=3; %window size
  x=size(f,1)/a; y=size(f,2)/b; %f is the original image
  m=a*ones(1,x); n=b*ones(1,y);
  I=mat2cell(f,m,n);
  </code></pre>