UIImageView contentMode not working after blur effect application - ios

Question

I'm attempting to set the image property of a UIImageView to an image I'm blurring with CoreImage. The code works perfectly with an unfiltered image, but when I set the background image to the filtered image, contentMode appears to stop working for the UIImageView -- instead of aspect filling, the image becomes vertically stretched. In addition to setting contentMode in code, I also set it on the storyboard but the result was the same.
I'm using Swift 2 / Xcode 7.
func updateBackgroundImage(image: UIImage) {
backgroundImage.contentMode = .ScaleAspectFill
backgroundImage.layer.masksToBounds = true
backgroundImage.image = blurImage(image)
}
func blurImage(image: UIImage) -> UIImage {
let imageToBlur = CIImage(image: image)!
let blurfilter = CIFilter(name: "CIGaussianBlur")!
blurfilter.setValue(10, forKey: kCIInputRadiusKey)
blurfilter.setValue(imageToBlur, forKey: "inputImage")
let resultImage = blurfilter.valueForKey("outputImage") as! CIImage
let croppedImage: CIImage = resultImage.imageByCroppingToRect(CGRectMake(0, 0, imageToBlur.extent.size.width, imageToBlur.extent.size.height))
let blurredImage = UIImage(CIImage: croppedImage)
return blurredImage
}
Why is filtering with CIImage causing my image to ignore contentMode and how do I fix the issue?

Answer 1

Solution is to replace your line:
let blurredImage = UIImage(CIImage: croppedImage)
with these 2 lines:
let context = CIContext(options: nil)
let blurredImage = UIImage (CGImage: context.createCGImage(croppedImage, fromRect: croppedImage.extent))
So your full blurImage function would look like this:
func blurImage(image: UIImage) -> UIImage {
let imageToBlur = CIImage(image: image)!
let blurfilter = CIFilter(name: "CIGaussianBlur")!
blurfilter.setValue(10, forKey: kCIInputRadiusKey)
blurfilter.setValue(imageToBlur, forKey: "inputImage")
let resultImage = blurfilter.valueForKey("outputImage") as! CIImage
let croppedImage: CIImage = resultImage.imageByCroppingToRect(CGRectMake(0, 0, imageToBlur.extent.size.width, imageToBlur.extent.size.height))
let context = CIContext(options: nil)
let blurredImage = UIImage (CGImage: context.createCGImage(croppedImage, fromRect: croppedImage.extent))
return blurredImage
}