Swift images get stretched - swift

Question

So I am totally new to programming and swift, this is my second week of trying to code. A lot of fun but a lot of errors as well. So I want to make an app where the user can choose a photo from their gallery or make a photo using there camera, and after a press of a button, this image will get pixalised(using the Core Image function).
The problem is whenever I press the button, the image seems to get stretched, and I can't figure out why. After browsing a picture:
After pressing the button:
Thanks for any answers!
My code is as follows:
import UIKit
class ViewController: UIViewController,UIImagePickerControllerDelegate,UINavigationControllerDelegate {
#IBOutlet weak var myImageView: UIImageView!
let picker = UIImagePickerController()
func noCamera(){
let alertVC = UIAlertController(title: "No Camera", message: "Don't try it on a computer Dumbass!", preferredStyle: .Alert)
let okAction = UIAlertAction(title: "Sorry about that :(", style:.Default, handler: nil)
alertVC.addAction(okAction)
presentViewController(alertVC, animated: true, completion: nil)
}
#IBAction func photofromLibrary(sender: UIBarButtonItem) {
picker.allowsEditing = false //2
picker.sourceType = .PhotoLibrary //3
picker.modalPresentationStyle = .Popover
presentViewController(picker, animated: true, completion: nil)//4
picker.popoverPresentationController?.barButtonItem = sender
}
#IBAction func shootPhoto(sender: UIButton) {
if UIImagePickerController.availableCaptureModesForCameraDevice(.Rear) != nil {
picker.allowsEditing = false
picker.sourceType = UIImagePickerControllerSourceType.Camera
picker.cameraCaptureMode = .Photo
presentViewController(picker, animated: true, completion: nil)
} else {
noCamera()
}
}
#IBAction func pixelise(sender: UIButton) {
// 1
let ciImage = CIImage(image: myImageView.image)
// 2
var filter = CIFilter(name: "CIPixellate")
filter.setDefaults()
filter.setValue(ciImage, forKey: kCIInputImageKey)
myImageView.contentMode = .ScaleAspectFit
// 3
var outputImage = filter.outputImage
var newImage = UIImage(CIImage: outputImage)
myImageView.image = newImage
}
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
picker.delegate = self
}
//MARK: Delegates
func imagePickerController(picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [NSObject : AnyObject]) {
var chosenImage = info[UIImagePickerControllerOriginalImage] as! UIImage //2
myImageView.contentMode = .ScaleAspectFit //3
myImageView.image = chosenImage //4
dismissViewControllerAnimated(true, completion: nil) //5
}
func imagePickerControllerDidCancel(picker: UIImagePickerController) {
dismissViewControllerAnimated(true, completion: nil)
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}

Answer 1

The process of converting CIImage to UIImage consists of creating a CIContext, then creating a CGImage using that context, and then creating a UIImage from that:
// 1
let ciImage = CIImage(image: image)
// 2
let filter = CIFilter(name: "CIPixellate")
filter.setDefaults()
filter.setValue(ciImage, forKey: kCIInputImageKey)
// 3
let context = CIContext(options: nil)
let cgImage = context.createCGImage(filter.outputImage, fromRect: CGRect(x: 0, y: 0, width: image.size.width, height: image.size.height))
let outputImage = UIImage(CGImage: cgImage)
That yields: