title: Divide images into four equal images
body: <p>How to divide a set of images which (<code>512*512</code>) into four equal images; each is <code>256*256</code> and this repeated for <code>150</code> images ?</p>
  
  <pre><code>I = imread(['file',num2str(i),'.tif']);
  I1 = I(1:size(I,1)/2,1:size(I,2)/2,:);
  I2 = I(size(I,1)/2+1:size(I,1),1:size(I,2)/2,:);
  I3 = I(1:size(I,1)/2,size(I,2)/2+1:size(I,2),:);
  I4 = I(size(I,1)/2+1:size(I,1),size(I,2)/2+1:size(I,2),:);
  </code></pre>