UIImage Image Processing extensions using the vDSP/Accelerate framework. 
Fast Image Blur/Sharpen/Emboss/Matrix operations for UIImage. 
REQUIRES IOS 4.0 and The Accelerate framework.
I was in desperate need of a fast blur operation for UIImages and the OpenGL 
solutions I've seen are a little complicated for my needs, these aren't quite 
as fast but are potentially very powerful and still quite fast relative to 
hand coding loops. 
Usage:
- Ensure your project is set with a base and deployment target > 4.0
- Include the Accelerate Framework in your project
- Copy the UIImage+DSP.h and UIImage+DSP.m classes into your project
- In any class where you wish to use the functions import UIImage+DSP.h
- Call the imageByApplying... methods, these return an auto-released UIImage.
blur example:
 UIImage* src = [UIImage imageNamed:@"image.png"];
 UIImage* blurred = [src imageByApplyingGaussianBlur3x3];
Please feel free to send any bugfixes/pull requests on if you've got something good!