title: How to read chunks of an image?
body: <p>Many many sites uses this technique (facebook, google as well)</p>
  
  <p>For example, open facebook.com</p>
  
  <p>Save this page (not as *.MHTM but HTML with images) (mean login page)</p>
  
  <p>It saves:</p>
  
  <p>facebook_files(dir)
  facebook.html(file)</p>
  
  <p>Then inside the folder, You can see one GIF file which containts all primary images for the page.</p>
  
  <p>The question is: How to read many chunks inside one file??
  And how to call this approach?</p>