title: How to implement a box or gaussian blur on iOS
body: <p>I want to be able to take an image and blur it relatively quickly (say in 0.1 sec). Image size would almost never be larger than 256 x 256 px.</p>
  
  <p>Do I have to loop thru every pixel and average them with neighbors or is there a higher-level way that I could do this?</p>
  
  <p><strong>PS</strong>: I am aware that multiple box blurs can approximate a gaussian blur.</p>