I use following in my app.
func applyBlurEffect(image: UIImage){
var imageToBlur = CIImage(image: image)
var blurfilter = CIFilter(name: "CIGaussianBlur")
blurfilter.setValue(imageToBlur, forKey: "inputImage")
var resultImage = blurfilter.valueForKey("outputImage") as CIImage
var blurredImage = UIImage(CIImage: resultImage)
self.blurImageView.image = blurredImage
}