Я создал пользовательскую камеру и реализовал приведенный ниже код для обрезки снятого изображения, я показал направляющие в слое предварительного просмотра, поэтому я хочу обрезать изображение, которое появляется в этой области.
func imageByCropToRect(rect:CGRect, scale:Bool) -> UIImage {
var rect = rect
var scaleFactor: CGFloat = 1.0
if scale {
scaleFactor = self.scale
rect.origin.x *= scaleFactor
rect.origin.y *= scaleFactor
rect.size.width *= scaleFactor
rect.size.height *= scaleFactor
}
var image: UIImage? = nil;
if rect.size.width > 0 && rect.size.height > 0 {
let imageRef = self.cgImage!.cropping(to: rect)
image = UIImage(cgImage: imageRef!, scale: scaleFactor, orientation: self.imageOrientation)
}
return image!
}
Этот код просто отлично работает, когда & дает точное обрезанное изображение, когда прокомментирована строка кода ниже, хотя я хочу, чтобы потоковая передача изображения была полноэкранной, поэтому я должен использовать приведенную ниже строку кода. Изображение как-то уменьшается.
(self.previewLayer as! AVCaptureVideoPreviewLayer).videoGravity = AVLayerVideoGravity.resizeAspectFill
Как решить эту проблему? Код обрезки неправильный?
Вот полный код класса
import UIKit
import AVFoundation
class CameraViewController: UIViewController {
@IBOutlet weak var guideImageView: UIImageView!
@IBOutlet weak var guidesView: UIView!
@IBOutlet weak var cameraPreviewView: UIView!
@IBOutlet weak var cameraButtonView: UIView!
@IBOutlet weak var captureButton: UIButton!
var captureSession = AVCaptureSession()
var previewLayer: CALayer!
var captureDevice: AVCaptureDevice!
/// This will be true when the user clicks on the click photo button.
var takePhoto = false
override func viewDidLoad() {
super.viewDidLoad()
}
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
captureSession = AVCaptureSession()
previewLayer = CALayer()
takePhoto = false
requestAuthorization()
}
private func userinteractionToButton(_ interaction: Bool) {
captureButton.isEnabled = interaction
}
/// This function will request authorization, If authorized then start the camera.
private func requestAuthorization() {
switch AVCaptureDevice.authorizationStatus(for: AVMediaType.video) {
case .authorized:
prepareCamera()
case .denied, .restricted, .notDetermined:
AVCaptureDevice.requestAccess(for: AVMediaType.video, completionHandler: { (granted) in
if !Thread.isMainThread {
DispatchQueue.main.async {
if granted {
self.prepareCamera()
} else {
let alert = UIAlertController(title: "unable_to_access_the_Camera", message: "to_enable_access_go_to_setting_privacy_camera_and_turn_on_camera_access_for_this_app", preferredStyle: UIAlertControllerStyle.alert)
alert.addAction(UIAlertAction(title: "ok", style: .default, handler: {_ in
self.navigationController?.popToRootViewController(animated: true)
}))
self.present(alert, animated: true, completion: nil)
}
}
} else {
if granted {
self.prepareCamera()
} else {
let alert = UIAlertController(title: "unable_to_access_the_Camera", message: "to_enable_access_go_to_setting_privacy_camera_and_turn_on_camera_access_for_this_app", preferredStyle: UIAlertControllerStyle.alert)
alert.addAction(UIAlertAction(title: "ok", style: .default, handler: {_ in
self.navigationController?.popToRootViewController(animated: true)
}))
self.present(alert, animated: true, completion: nil)
}
}
})
}
}
/// Will see if the primary camera is avilable, If found will call method which will asign the available device to the AVCaptureDevice.
private func prepareCamera() {
// Resets the session.
self.captureSession.sessionPreset = AVCaptureSession.Preset.photo
if #available(iOS 10.0, *) {
let availableDevices = AVCaptureDevice.DiscoverySession(deviceTypes: [AVCaptureDevice.DeviceType.builtInWideAngleCamera], mediaType: AVMediaType.video, position: .back).devices
self.assignCamera(availableDevices)
} else {
// Fallback on earlier versions
// development, need to test this on iOS 8
if let availableDevices = AVCaptureDevice.default(for: AVMediaType.video) {
self.assignCamera([availableDevices])
} else {
self.showAlert()
}
}
}
/// Assigns AVCaptureDevice to the respected the variable, will begin the session.
///
/// - Parameter availableDevices: [AVCaptureDevice]
private func assignCamera(_ availableDevices: [AVCaptureDevice]) {
if availableDevices.first != nil {
captureDevice = availableDevices.first
beginSession()
} else {
self.showAlert()
}
}
/// Configures the camera settings and begins the session, this function will be responsible for showing the image on the UI.
private func beginSession() {
do {
let captureDeviceInput = try AVCaptureDeviceInput(device: captureDevice)
captureSession.addInput(captureDeviceInput)
} catch {
print(error.localizedDescription)
}
let previewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
self.previewLayer = previewLayer
self.cameraPreviewView.layer.addSublayer(self.previewLayer)
self.previewLayer.frame = self.view.layer.frame
self.previewLayer.frame.origin.y = +self.cameraPreviewView.frame.origin.y
(self.previewLayer as! AVCaptureVideoPreviewLayer).videoGravity = AVLayerVideoGravity.resizeAspectFill
self.previewLayer.masksToBounds = true
self.cameraPreviewView.clipsToBounds = true
captureSession.startRunning()
self.view.bringSubview(toFront: self.cameraPreviewView)
self.view.bringSubview(toFront: self.cameraButtonView)
self.view.bringSubview(toFront: self.guidesView)
let dataOutput = AVCaptureVideoDataOutput()
dataOutput.videoSettings = [((kCVPixelBufferPixelFormatTypeKey as NSString) as String):NSNumber(value:kCVPixelFormatType_32BGRA)]
dataOutput.alwaysDiscardsLateVideoFrames = true
if captureSession.canAddOutput(dataOutput) {
captureSession.addOutput(dataOutput)
}
captureSession.commitConfiguration()
let queue = DispatchQueue(label: "com.letsappit.camera")
dataOutput.setSampleBufferDelegate(self, queue: queue)
self.userinteractionToButton(true)
}
/// Get the UIImage from the given CMSampleBuffer.
///
/// - Parameter buffer: CMSampleBuffer
/// - Returns: UIImage?
func getImageFromSampleBuffer(buffer:CMSampleBuffer, orientation: UIImageOrientation) -> UIImage? {
if let pixelBuffer = CMSampleBufferGetImageBuffer(buffer) {
let ciImage = CIImage(cvPixelBuffer: pixelBuffer)
let context = CIContext()
let imageRect = CGRect(x: 0, y: 0, width: CVPixelBufferGetWidth(pixelBuffer), height: CVPixelBufferGetHeight(pixelBuffer))
if let image = context.createCGImage(ciImage, from: imageRect) {
return UIImage(cgImage: image, scale: UIScreen.main.scale, orientation: orientation)
}
}
return nil
}
/// This function will destroy the capture session.
func stopCaptureSession() {
self.captureSession.stopRunning()
if let inputs = captureSession.inputs as? [AVCaptureDeviceInput] {
for input in inputs {
self.captureSession.removeInput(input)
}
}
}
func showAlert() {
let alert = UIAlertController(title: "Unable to access the camera", message: "It appears that either your device doesn't have camera or its broken", preferredStyle: .alert)
alert.addAction(UIAlertAction(title: "cancel", style: .cancel, handler: {_ in
self.navigationController?.dismiss(animated: true, completion: nil)
}))
self.present(alert, animated: true, completion: nil)
}
@IBAction func didTapClick(_ sender: Any) {
userinteractionToButton(false)
takePhoto = true
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "showImage" {
let vc = segue.destination as! ShowImageViewController
vc.image = sender as! UIImage
}
}
}
extension CameraViewController: AVCaptureVideoDataOutputSampleBufferDelegate {
func captureOutput(_ captureOutput: AVCaptureOutput, didOutput sampleBuffer: CMSampleBuffer, from connection: AVCaptureConnection) {
if connection.isVideoOrientationSupported {
connection.videoOrientation = .portrait
}
if takePhoto {
takePhoto = false
// Rotation should be unlocked to work.
var orientation = UIImageOrientation.up
switch UIDevice.current.orientation {
case .landscapeLeft:
orientation = .left
case .landscapeRight:
orientation = .right
case .portraitUpsideDown:
orientation = .down
default:
orientation = .up
}
if let image = self.getImageFromSampleBuffer(buffer: sampleBuffer, orientation: orientation) {
DispatchQueue.main.async {
let newImage = image.imageByCropToRect(rect: self.guideImageView.frame, scale: true)
self.stopCaptureSession()
self.previewLayer.removeFromSuperlayer()
self.performSegue(withIdentifier: "showImage", sender: newImage)
}
}
}
}
}
Вот изображение иерархии представлений 
