View Controller to Generate a QR Code with swift on macOS. Requires a NSImageView, NSTextField and NSButton

QRGen.swift

//
//  ViewController.swift
//  QRGen
//
//  Created by Keiran Smith on 01/10/2016.
//  Copyright © 2016 Keiran Smith. All rights reserved.
//

import Cocoa
import CoreImage

class ViewController: NSViewController {

	var qrcodeImage: CIImage!
	
	@IBOutlet weak var imgCode: NSImageView!
	@IBOutlet weak var txtEncode: NSTextField!
	
	@IBAction func btnGenerate(_ sender: NSButton) {
		if txtEncode.stringValue == "" {
			return
		}
		
		let data = txtEncode.stringValue.data(using: String.Encoding.isoLatin1, allowLossyConversion: false)
		
		let filter = CIFilter(name: "CIQRCodeGenerator")
		
		filter?.setValue(data, forKey: "inputMessage")
		filter?.setValue("Q", forKey: "inputCorrectionLevel")
		
		qrcodeImage = filter?.outputImage
		
		/*
		Convert the Image
		*/
		let size = NSSize(width: 219, height: 219)
		let outputImage = filter?.value(forKey: kCIOutputImageKey) as! CIImage
		let scaleX = imgCode.frame.size.width / qrcodeImage.extent.size.width
		let scaleY = imgCode.frame.size.height / qrcodeImage.extent.size.height
		qrcodeImage.applying(CGAffineTransform(scaleX: scaleX, y: scaleY))
		
		let outputImageRect = NSRectFromCGRect(qrcodeImage.extent)
		let qrImage = NSImage(size: size)
		qrImage.lockFocus()
		outputImage.draw(at: NSZeroPoint, from: outputImageRect, operation: NSCompositingOperation.sourceOver, fraction: 1.0)
		qrImage.unlockFocus()
		qrImage.size = size
		
		print("Displaying QR Code")
		imgCode.image = qrImage
	}

	
	override func viewDidLoad() {
		super.viewDidLoad()

		// Do any additional setup after loading the view.
	}

	override var representedObject: Any? {
		didSet {
		// Update the view, if already loaded.
		}
	}


}

tried to convert it to Swift3, but

qrcodeImage.applying(CGAffineTransform(scaleX: scaleX, y: scaleY))

seems not to work properly