title: How to implement a real time iOS7 blur effect in the UITableViewCell's background
body: <p>I want the UITableViewCell's background to have an iOS7 blur effect. It's dynamic, means, while the cell is scrolling, its blurred background should change depend on the color below.</p>
  
  <p>I found some relative topics.</p>
  
  <p><a href="https://stackoverflow.com/questions/11601166/iphone-sdk-frosted-glass-ios-7-blur-effect">iPhone SDK - Frosted Glass (iOS 7 Blur) Effect</a>.  It introduce GPUImage. It about still image, I didn't figure out how to make a dynamic one.</p>
  
  <p><a href="https://stackoverflow.com/questions/17704240/ios-7-dynamic-blur-effect-like-in-control-center">iOS 7 dynamic blur effect like in Control Center</a>. It use UIToolbar as the background of cell, taking advantage of system built-in blur effect. It works great, but just the transparency is a little low. I have adjusted the alpha of tool bar, but it doesn't ideal. </p>