gistfile1.m

//  Needs CoreImage.framework

- (UIImage *)blurredImageWithImage:(UIImage *)sourceImage{
    
    //  Create our blurred image
    CIContext *context = [CIContext contextWithOptions:nil];
    CIImage *inputImage = [CIImage imageWithCGImage:sourceImage.CGImage];
    
    //  Setting up Gaussian Blur
    CIFilter *filter = [CIFilter filterWithName:@"CIGaussianBlur"];
    [filter setValue:inputImage forKey:kCIInputImageKey];
    [filter setValue:[NSNumber numberWithFloat:15.0f] forKey:@"inputRadius"];
    CIImage *result = [filter valueForKey:kCIOutputImageKey];
    
    /*  CIGaussianBlur has a tendency to shrink the image a little, this ensures it matches 
     *  up exactly to the bounds of our original image */
    CGImageRef cgImage = [context createCGImage:result fromRect:[inputImage extent]];
    
    UIImage *retVal = [UIImage imageWithCGImage:cgImage];
    CGImageRelease(cgImage);
    
    return retVal;
}