title: Create a tilt-shift filter like instagram in objective C
body: <p>I trying to create a tilt-shift filter of the image like instagram or iDarkroom in iOS.</p>
  
  <p>My proposed method is use different Gaussian Blur levels for the partial image. But I don't known how to control the area to apply different Gaussian Blur Levels, especially when User can change the effect area by rotate, scale, etc.</p>
  
  <p>Sorry about my complex presentation but simply, I want to create a tilf-shift tool for iOS like in Instagram. </p>
  
  <p>I search and found this powerful framework <a href="https://github.com/BradLarson/GPUImage" rel="nofollow noreferrer">https://github.com/BradLarson/GPUImage</a>, but it's not good solution if include this huge framework to my tiny apps</p>