How to capture picture with AVCaptureSession in Swift?

AVCaptureSession Sample

import UIKitimport AVFoundationclass ViewController: UIViewController {    let captureSession = AVCaptureSession()    let stillImageOutput = AVCaptureStillImageOutput()    var error: NSError?    override func viewDidLoad() {        super.viewDidLoad()        let devices = AVCaptureDevice.devices().filter{ $0.hasMediaType(AVMediaTypeVideo) && $0.position == AVCaptureDevicePosition.Back }        if let captureDevice = devices.first as? AVCaptureDevice  {            captureSession.addInput(AVCaptureDeviceInput(device: captureDevice, error: &error))            captureSession.sessionPreset = AVCaptureSessionPresetPhoto            captureSession.startRunning()            stillImageOutput.outputSettings = [AVVideoCodecKey:AVVideoCodecJPEG]            if captureSession.canAddOutput(stillImageOutput) {                captureSession.addOutput(stillImageOutput)            }            if let previewLayer = AVCaptureVideoPreviewLayer(session: captureSession) {                previewLayer.bounds = view.bounds                previewLayer.position = CGPointMake(view.bounds.midX, view.bounds.midY)                previewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill                let cameraPreview = UIView(frame: CGRectMake(0.0, 0.0, view.bounds.size.width, view.bounds.size.height))                cameraPreview.layer.addSublayer(previewLayer)                cameraPreview.addGestureRecognizer(UITapGestureRecognizer(target: self, action:"saveToCamera:"))                view.addSubview(cameraPreview)            }        }    }    func saveToCamera(sender: UITapGestureRecognizer) {        if let videoConnection = stillImageOutput.connectionWithMediaType(AVMediaTypeVideo) {            stillImageOutput.captureStillImageAsynchronouslyFromConnection(videoConnection) {                (imageDataSampleBuffer, error) -> Void in                let imageData = AVCaptureStillImageOutput.jpegStillImageNSDataRepresentation(imageDataSampleBuffer)                 UIImageWriteToSavedPhotosAlbum(UIImage(data: imageData), nil, nil, nil)            }        }    }    override func didReceiveMemoryWarning() {        super.didReceiveMemoryWarning()    }}

UIImagePickerController Sample

import UIKitclass ViewController: UIViewController, UINavigationControllerDelegate, UIImagePickerControllerDelegate {    let imagePicker = UIImagePickerController()    @IBOutlet weak var imageViewer: UIImageView!    override func viewDidLoad() {        super.viewDidLoad()        // Do any additional setup after loading the view, typically from a nib.    }    override func didReceiveMemoryWarning() {        super.didReceiveMemoryWarning()        // Dispose of any resources that can be recreated.    }    func imagePickerController(picker: UIImagePickerController, didFinishPickingImage image: UIImage!, editingInfo: [NSObject : AnyObject]!) {            dismissViewControllerAnimated(true, completion: nil)             imageViewer.image = image    }    @IBAction func presentImagePicker(sender: AnyObject) {        if UIImagePickerController.isCameraDeviceAvailable( UIImagePickerControllerCameraDevice.Front) {            imagePicker.delegate = self            imagePicker.sourceType = UIImagePickerControllerSourceType.Camera            presentViewController(imagePicker, animated: true, completion: nil)        }    }}

As AVCaptureStillImageOutput is deprecated, I created another Swift example of using AVCaptureSession and AVCapturePhotoOutput in iOS 10. Check this out.