I am trying to iterate over images in Photo Library and extract faces using CIDetector. The images are required to keep their original resolutions. To do so, I taking the following steps: 1- Getting assets given a date interval (usually more than a year) func loadAssets(from fromDate: Date, to toDate: Date, completion: @escaping ([PHAsset]) -> Void) { fetchQueue.async { let authStatus = PHPhotoLibrary.authorizationStatus() if authStatus == .authorized || authStatus == .limited { let options = PHFetchOptions() options.predicate = NSPredicate(format: "creationDate >= %@ && creationDate <= %@", fromDate as CVarArg, toDate as CVarArg) options.sortDescriptors = [NSSortDescriptor(key: "creationDate", ascending: false)] let result: PHFetchResult = PHAsset.fetchAssets(with: .image, options: options) var _assets = [PHAsset]() result.enumerateObjects { object, count, stop in _assets.append(object) } completion(_assets) } else { completion([]) } } } where: let fetchQueue = DispatchQueue.global(qos: .background) 2- Extracting faces I then extract face images using: func detectFaces(in image: UIImage, accuracy: String = CIDetectorAccuracyLow, completion: @escaping ([UIImage]) -> Void) { faceDetectionQueue.async { var faceImages = [UIImage]() let outputImageSize: CGFloat = 200.0 / image.scale guard let ciImage = CIImage(image: image), let faceDetector = CIDetector(ofType: CIDetectorTypeFace, context: nil, options: [CIDetectorAccuracy: accuracy]) else { completion(faceImages); return } let faces = faceDetector.features(in: ciImage) // Crash happens here let group = DispatchGroup() for face in faces { group.enter() if let face = face as? CIFaceFeature { let faceBounds = face.bounds let offset: CGFloat = floor(min(faceBounds.width, faceBounds.height) * 0.2) let inset = UIEdgeInsets(top: -offset, left: -offset, bottom: -offset, right: -offset) let rect = faceBounds.inset(by: inset) let croppedFaceImage = ciImage.cropped(to: rect) let scaledImage = croppedFaceImage .transformed(by: CGAffineTransform(scaleX: outputImageSize / croppedFaceImage.extent.width, y: outputImageSize / croppedFaceImage.extent.height)) faceImages.append(UIImage(ciImage: scaledImage)) group.leave() } else { group.leave() } } group.notify(queue: self.faceDetectionQueue) { completion(faceImages) } } } where: private let faceDetectionQueue = DispatchQueue(label: "face detection queue", qos: DispatchQoS.background, attributes: [], autoreleaseFrequency: DispatchQueue.AutoreleaseFrequency.workItem, target: nil) I use the following extension to get the image from assets: extension PHAsset { var image: UIImage { autoreleasepool { let manager = PHImageManager.default() let options = PHImageRequestOptions() var thumbnail = UIImage() let rect = CGRect(x: 0, y: 0, width: pixelWidth, height: pixelHeight) options.isSynchronous = true options.deliveryMode = .highQualityFormat options.resizeMode = .exact options.normalizedCropRect = rect options.isNetworkAccessAllowed = true manager.requestImage(for: self, targetSize: rect.size, contentMode: .aspectFit, options: options, resultHandler: {(result, info) -> Void in if let result = result { thumbnail = result } else { thumbnail = UIImage() } }) return thumbnail } } } The code works fine for a few (usually less that 50) assets, but for more number of images it crashes at: let faces = faceDetector.features(in: ciImage) // Crash happens here I get this error: validateComputeFunctionArguments:858: failed assertion `Compute Function(ciKernelMain): missing sampler binding at index 0 for [0].' If I reduce the size of the image fed to detectFaces(:) e.g. 400 px, I can analyze a few hundred images (usually less than 1000) but as I mentioned, using the asset's image in the original size is a requirement. My guess is it has something to do with a memory issue when I try to extract faces with CIDetector. Any idea what this error is about and how I can fix the issue?

I have an AVFoundation-based live camera view. There is a button by which I am calling AVCaptureDevice.showSystemUserInterface(.videoEffects) so that the user can activate the Portrait Effect. I have also opted in by setting "Camera — Opt in for Portrait Effect" to true in info.plist. However, upon tapping on the button I see this screen (The red crossed-off part is the app name): I am expecting to see something like this: Do you have any idea why that might be?

I have an AVFoundation-based live camera view. There is a button by which I am calling AVCaptureDevice.showSystemUserInterface(.videoEffects) so that the user can activate the Portrait Effect. I have also opted in by setting "Camera — Opt in for Portrait Effect" to true in info.plist. However, upon tapping on the button I see this screen (The red crossed-off part is the app name): I am expecting to see something like this: Do you have any idea why that might be?

I have a camera view based on AVFoundation. Any idea how I can switch to Portrait Effect in iOS's Control Center like SnapChat?

I am using AVFoundation for live camera view. I can get my device from the current video input (of type AVCaptureDeviceInput) like: let device = videoInput.device The device's active format has a isPortraitEffectSupported. How can I set the Portrait Effect on and off in live camera view? I setup the camera like this: private var videoInput: AVCaptureDeviceInput! private let session = AVCaptureSession() private(set) var isSessionRunning = false private var renderingEnabled = true private let videoDataOutput = AVCaptureVideoDataOutput() private let photoOutput = AVCapturePhotoOutput() private(set) var cameraPosition: AVCaptureDevice.Position = .front func configureSession() { sessionQueue.async { [weak self] in guard let strongSelf = self else { return } if strongSelf.setupResult != .success { return } let defaultVideoDevice: AVCaptureDevice? = strongSelf.videoDeviceDiscoverySession.devices.first(where: {$0.position == strongSelf.cameraPosition}) guard let videoDevice = defaultVideoDevice else { print("Could not find any video device") strongSelf.setupResult = .configurationFailed return } do { strongSelf.videoInput = try AVCaptureDeviceInput(device: videoDevice) } catch { print("Could not create video device input: \(error)") strongSelf.setupResult = .configurationFailed return } strongSelf.session.beginConfiguration() strongSelf.session.sessionPreset = AVCaptureSession.Preset.photo // Add a video input. guard strongSelf.session.canAddInput(strongSelf.videoInput) else { print("Could not add video device input to the session") strongSelf.setupResult = .configurationFailed strongSelf.session.commitConfiguration() return } strongSelf.session.addInput(strongSelf.videoInput) // Add a video data output if strongSelf.session.canAddOutput(strongSelf.videoDataOutput) { strongSelf.session.addOutput(strongSelf.videoDataOutput) strongSelf.videoDataOutput.videoSettings = [kCVPixelBufferPixelFormatTypeKey as String: Int(kCVPixelFormatType_32BGRA)] strongSelf.videoDataOutput.setSampleBufferDelegate(self, queue: strongSelf.dataOutputQueue) } else { print("Could not add video data output to the session") strongSelf.setupResult = .configurationFailed strongSelf.session.commitConfiguration() return } // Add photo output if strongSelf.session.canAddOutput(strongSelf.photoOutput) { strongSelf.session.addOutput(strongSelf.photoOutput) strongSelf.photoOutput.isHighResolutionCaptureEnabled = true } else { print("Could not add photo output to the session") strongSelf.setupResult = .configurationFailed strongSelf.session.commitConfiguration() return } strongSelf.session.commitConfiguration() } } func prepareSession(completion: @escaping (SessionSetupResult) -&gt; Void) { sessionQueue.async { [weak self] in guard let strongSelf = self else { return } switch strongSelf.setupResult { case .success: strongSelf.addObservers() if strongSelf.photoOutput.isDepthDataDeliverySupported { strongSelf.photoOutput.isDepthDataDeliveryEnabled = true } if let photoOrientation = AVCaptureVideoOrientation(interfaceOrientation: interfaceOrientation) { if let unwrappedPhotoOutputConnection = strongSelf.photoOutput.connection(with: .video) { unwrappedPhotoOutputConnection.videoOrientation = photoOrientation } } strongSelf.dataOutputQueue.async { strongSelf.renderingEnabled = true } strongSelf.session.startRunning() strongSelf.isSessionRunning = strongSelf.session.isRunning strongSelf.mainQueue.async { strongSelf.previewView.videoPreviewLayer.session = strongSelf.session } completion(strongSelf.setupResult) default: completion(strongSelf.setupResult) } } } Then to I set isPortraitEffectsMatteDeliveryEnabled like this: func setPortraitAffectActive(_ state: Bool) { sessionQueue.async { [weak self] in guard let strongSelf = self else { return } if strongSelf.photoOutput.isPortraitEffectsMatteDeliverySupported { strongSelf.photoOutput.isPortraitEffectsMatteDeliveryEnabled = state } } } However, I don't see any Portrait Effect in the live camera view! Any ideas why?

I am trying to develop an ARKit iOS app. Is it possible to use Apple Watch to see a live view from ARKit (run from the parent iOS app)?