Photos & Camera

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Explore technical aspects of capturing high-quality photos and videos, including exposure control, focus modes, and RAW capture options.

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PHPickerFilter doesn't always apply in Collections tab when using PHPickerViewController
Hi everyone, I’m running into an issue with PHPickerFilter when using PHPickerViewController. When I configure the picker with a .videos and .livePhotos filter, it seems to work correctly in the Photos tab. However, when I switch to the Collections tab, the filter doesn’t always apply — users can still see and select static image assets in certain collections (e.g. from one of the People & Pets sections). Here’s a simplified snippet of my setup: var configuration = PHPickerConfiguration(photoLibrary: .shared()) configuration.selectionLimit = 1 var filters = [PHPickerFilter]() filters.append(.videos) filters.append(.livePhotos) configuration.filter = PHPickerFilter.any(of: filters) configuration.preferredAssetRepresentationMode = .current let picker = PHPickerViewController(configuration: configuration) picker.delegate = self present(picker, animated: true) Expected behavior: The picker should consistently respect the filter across both Photos and Collections tabs, only showing assets that match the filter. Actual behavior: The filter seems to apply correctly in the Photos tab, but in the Collections tab, other asset types are still visible/selectable. Has anyone else encountered this behavior? Is this expected or a known issue, or am I missing something in the configuration? Thanks in advance!
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312
4d
Only fetch PHAssets from the current user's iCloud Library
I'm working on a photo app and I want to allow the user to display, edit and delete photos. I can fetch all photos using PHAsset.fetchAssets(with: options). This works as intended. However, I can't seem to find a way to prevent the user from seeing photos from a Shared Library. The PHAssetSourceType only contains typeCloudShared to only show items from a specific album; not library. How can I filter by iCloud Shared Library?
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342
1w
Images with unusual color spaces not correctly loaded by Core Image
Some users reported that their images are not loading correctly in our app. After a lot of debugging we identified the following: This only happens when the app is build for Mac Catalyst. Not on iOS, iPadOS, or “real” macOS (AppKit). The images in question have unusual color spaces. We observed the issue for uRGB and eciRGB v2. Those images are rendered correctly in Photos and Preview on all platforms. When displaying the image inside of a UIImageView or in a SwiftUI Image, they render correctly. The issue only occurs when loading the image via Core Image. When comparing the different Core Image render graphs between AppKit (working) and Catalyst (faulty) builds, they look identical—except for the result. Mac (AppKit): Catalyst: Something seems to be off when Core Image tries to load an image with foreign color space in Catalyst. We identified a workaround: By using a CGImageDestination to transcode the image using the kCGImageDestinationOptimizeColorForSharing option, Image I/O will convert the image to sRGB (or similar) and Core Image is able to load the image correctly. However, one potentially loses fidelity this way. Or might there be a better workaround?
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91
Aug ’25
How to reliably detect user-modified photos?
I'm developing a photo backup app. To detect newly added or edited photos since the app launched, I keep a local dictionary in the format [localIdentifier: modification_date]. However, PHAsset.modificationDate is not reliable. It often changes unexpectedly, possibly due to system operations like iCloud metadata updates. Is there a more reliable way to detect whether a photo has been modified by user since the last app launch? I'm thinking about using content hash instead, but I'm not sure how heavy this operation is in terms of performance.
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53
Aug ’25
Green Line Appears in Thumbnails in Photos but Not in Actual Photo
Hello, I’ve encountered an issue where a green line appears only in the thumbnail view of an image in the iPhone photo gallery. The green line is not present in the actual image itself. Here are some additional details: • The issue occurs only when saving the image as a JPEG. When saved as PNG, the green line does not appear. • The green line also shows up when using the PHAsset method requestImage(for:targetSize:). Depending on the targetSize, the resulting image may contain the green line. • Interestingly, this issue does not appear on iPhone Xs Max running iOS 15.2.1. However, the green line does appear on iPhone 15 Pro Max running iOS 18.0.1 when viewing the same image. I have attached the problematic image for your reference. Following images are the screen captures that shows the issue occurring on my iPhone. iPhone 15 pro max (iOS 18.0.1) iPhone Xs Max (iOS 15.2.1 ) Could this be related to a display or gallery app issue on iOS? Any advice or solutions would be greatly appreciated. Thank you!
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1.2k
Oct ’24
Captured photos in wrong orientation
I'm building a custom camera screen that displays the camera image on a preview layer and then captures an image, using AVCaptureSession. When the picture is captured, I immediately load it into a UIImageView in order to display it to the user for approval. I've actually done this many times before, but this is the first time I've tried to do it in an app that supports interface rotation. If I hold the phone in Portrait mode and capture a picture, everything works as expected. When the user rotates the phone into Landscape orientation, I detect this and I replace the preview layer (AVCaptureVideoPreviewLayer) with a new one, specifying connection.videoRotationAngle in order to make the image appear in the right orientation. I'm a little surprised that this is necessary, and it's not a smooth transition, but that doesn't matter. What does matter is that when I capture the image, it is in the wrong orientation. I tried rotating it myself, but this doesn't seem to make any difference. What am I doing wrong?
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757
Nov ’24
AVCaptureDevice rotationCoordinator modifying CALayer on switching devices
I am trying to use AVCaptureDevice.rotationCoordinator API to observe angles for preview and capture and it seems there is an issue with the API when used with arbitrary CALayer (which is not a AVCaptureVideoPreviewLayer) and switching cameras. Here is my setup. The below function is defined in an actor class called CameraManager that performs setup of rotationCoordinator. func updateRotationCoordinator(_ callback:@escaping @MainActor (CGFloat) -> Void) { guard let device = sessionConfiguration.activeVideoInput?.device, let displayLayer = displayLayer else { return } cancellables.removeAll() rotationCoordinator = AVCaptureDevice.RotationCoordinator(device: device, previewLayer: displayLayer) guard let coordinator = rotationCoordinator else { return } coordinator.publisher(for: \.videoRotationAngleForHorizonLevelPreview) .receive(on: DispatchQueue.main) .sink { degrees in let radians = degrees * .pi / 180 MainActor.assumeIsolated { callback(radians) } } .store(in: &cancellables) } This works the very first time but when I switch cameras and call this function again, it throws a runtime error that view's layer is modified from a non-main thread. This happens at the very line where rotation coordinator is been recreated. It's not clear why initialising rotation coordinator should modify CALayer properties right in it's init method. Modifying properties of a view's layer off the main thread is not allowed: view <MyApp.DisplayLayerView: 0x102ffaf40> with nearest ancestor view controller <_TtGC7SwiftUI19UIHostingControllerGVS_15ModifiedContentVS_7AnyViewVS_12RootModifier__: 0x101f7fb80>; backtrace: ( 0 UIKitCore 0x0000000194a977b4 575E5140-FA6A-37C2-B00B-A4EACEDFDA53 + 22509492 1 UIKitCore 0x000000019358594c 575E5140-FA6A-37C2-B00B-A4EACEDFDA53 + 416076 2 QuartzCore 0x00000001927f5bd8 D8E8E86D-85AC-3C90-B2E1-940235ECAA18 + 43992 3 QuartzCore 0x00000001927f5a4c D8E8E86D-85AC-3C90-B2E1-940235ECAA18 + 43596 4 QuartzCore 0x000000019283a41c D8E8E86D-85AC-3C90-B2E1-940235ECAA18 + 324636 5 QuartzCore 0x000000019283a0a8 D8E8E86D-85AC-3C90-B2E1-940235ECAA18 + 323752 6 AVFCapture 0x00000001af072a18 09192166-E0B6-346C-B1C2-7C95C3EFF7F7 + 420376 7 MyApp.debug.dylib 0x0000000105fa3914 $s10MyApp15CapturePipelineC25updateRotationCoordinatoryyy12CoreGraphics7CGFloatVScMYccF + 972 8 MyApp.debug.dylib 0x00000001063ade40 $s10MyApp11CameraModelC18switchVideoDevicesyyYaFTY3_ + 72 9 MyApp.debug.dylib 0x0000000105fe3cbd $s10MyApp11ContentViewV4bodyQrvg7SwiftUI6VStackVyAE05TupleE0VyAE6HStackVyAIyAE6SpacerV_AE6ButtonVyAE0E0PAEE5frame5width6height9alignmentQr12CoreGraphics7CGFloatVSg_AyE9AlignmentVtFQOyAqEE11scaledToFitQryFQOyAqEE10imageScaleyQrAE5ImageV0Z0OFQOyA3__Qo__Qo__Qo_GtGG_AmKyAIyAKyAIyAqEE7paddingyQrAE4EdgeO3SetV_AYtFQOyAA07CaptureM0V_Qo__AOyAE4TextVGAmKyAIyA9__AqEEArstUQrAY_AYA_tFQOyAM_Qo_A9_tGGtGG_AmqEE10background_AUQrqd___A_tAePRd__lFQOyAqEEArstUQrAY_AYA_tFQOyA21__Qo__AqEEArstUQrAY_AYA_tFQOyAE06_ShapeE0VyAE9RectangleVAE5ColorVG_Qo_Qo_SgtGGtGGyXEfU0_A42_yXEfU_A10_yXEfU_yyScMYccfU_yyYacfU_TQ1_ + 1 10 MyApp.debug.dylib 0x0000000105ff06d9 $s10MyApp11ContentViewV4bodyQrvg7SwiftUI6VStackVyAE05TupleE0VyAE6HStackVyAIyAE6SpacerV_AE6ButtonVyAE0E0PAEE5frame5width6height9alignmentQr12CoreGraphics7CGFloatVSg_AyE9AlignmentVtFQOyAqEE11scaledToFitQryFQOyAqEE10imageScaleyQrAE5ImageV0Z0OFQOyA3__Qo__Qo__Qo_GtGG_AmKyAIyAKyAIyAqEE7paddingyQrAE4EdgeO3SetV_AYtFQOyAA07CaptureM0V_Qo__AOyAE4TextVGAmKyAIyA9__AqEEArstUQrAY_AYA_tFQOyAM_Qo_A9_tGGtGG_AmqEE10background_AUQrqd___A_tAePRd__lFQOyAqEEArstUQrAY_AYA_tFQOyA21__Qo__AqEEArstUQrAY_AYA_tFQOyAE06_ShapeE0VyAE9RectangleVAE5ColorVG_Qo_Qo_SgtGGtGGyXEfU0_A42_yXEfU_A10_yXEfU_yyScMYccfU_yyYacfU_TATQ0_ + 1 11 MyApp.debug.dylib 0x0000000105f9c595 $sxIeAgHr_xs5Error_pIegHrzo_s8SendableRzs5NeverORs_r0_lTRTQ0_ + 1 12 MyApp.debug.dylib 0x0000000105f9fb3d $sxIeAgHr_xs5Error_pIegHrzo_s8SendableRzs5NeverORs_r0_lTRTATQ0_ + 1 13 libswift_Concurrency.dylib 0x000000019c49fe39 E15CC6EE-9354-3CE5-AF91-F641CA8283E0 + 433721 )
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537
Feb ’25
Does PHAsset localIdentifier change after device transfer?
Hi, I’m working on a photo backup app. I track the PHAsset localIdentifier to determine which photos have been backed up and which haven’t. Recently, I’ve noticed that two users seem to have experienced the localIdentifier changes after transferring data to a new iPhone using Quick Start. Additionally, others on StackOverflow have mentioned that the localIdentifier sometimes changes after updating the iOS version. https://stackoverflow.com/questions/40094728/phobject-localidentifier-reliability I’d like to confirm the reliability of the localIdentifier after an iOS version upgrade or device transfer. Can I continue using these locally stored localIdentifiers? Or is there another recommended approach, such as using PHCloudIdentifier?
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365
Feb ’25
Why is my YCbCr to sRGB camera pipeline brighter Than Preview Layer? (420YpCbCr8BiPlanarFullRange, AVCaptureVideoPreviewLayer)
Hi all, I'm working on a custom Metal-based video pipeline using AVCaptureVideoDataOutput, and I've run into an unexpected issue related to exposure. Setup: I'm capturing video frames using kCVPixelFormatType_420YpCbCr8BiPlanarFullRange. In my Metal shader, I: Convert YCbCr (full range Rec.709) to linear Rec.709 RGB. Apply Rec.709 → sRGB gamma encoding. Output to .bgra8Unorm_srgb via MTKView. Everything renders correctly in terms of colorspace math, but the image appears significantly brighter (~+3 stops EV) compared to AVCaptureVideoPreviewLayer and the native iOS Camera app under the same camera exposure settings. What I’ve verified: The color transforms are correct: YCbCr709 to RGB, then linear to sRGB. I'm not applying any tone mapping or aggressive look LUTs yet. Camera exposure is locked using: device.setExposureModeCustom(duration: ..., iso: ...) The same EV (e.g., ISO 50, 1/125s, f/5.6) on my iPhone appears visually 3 stops brighter than on my digital cameras (Sony/Canon etc). To match the look of the preview layer or camera app, I have to simulate a ~–3 EV shift in my custom pipeline. Questions: Is AVCaptureVideoPreviewLayer applying extra tone mapping, digital gain, or contrast shaping (like OOTF etc)? Does the camera ISP expose "hotter" (i.e., with more light) internally for the preview layer than what we get in video frame buffers? Is there a standard way to compensate for this ISP behavior in custom pipelines using AVCaptureVideoDataOutput? Can this be accounted for using metadata (e.g., exposure bias, gain, gamma curve)?
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228
1w
Connect DSLR Camera issues By Using ImageCaptureCore Framework
Hi Apple Engineer, My App is using ImageCapture Framwork to connect DSLR Camera, Before iOS 18 this method is effective,but When I upgraded my iPhone and iPad, found my app can`t connect DSLR Camera, open Setting -> Privacy & Security -> Files and Folders permission, can‘t found my app, I swear it worked before iOS 18. I find other developers have the same problem. https://forums.developer.apple.com/forums/thread/756960 . https://developer.apple.com/forums/thread/765768. I also found a process for reproducing this problem in ios 18, Do reset all settings. Can you help me with this problem? Or tell me how to use the API properly.Look forward to your reply. Thank you very much.
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455
Oct ’24
why does tripple camera take photo faster than single camera device?
I found this phenomenon, and it can be reproduced stably. If I use a triple-camera to take a photo, if the picture is moving, or I move the phone, let's assume it moves horizontally, when I aim at an object, I press the shutter, which is called time T. At this time, the picture in the viewfinder is T0, and the photo produced is about T+100ms. If I use a single-camera to take a photo, use the same speed to move the phone to move the picture, and press the shutter when aiming at the same object, the photo produced is about T+400ms later. Let me describe the problem I encountered in another way. Suppose a pile of cards are placed horizontally on the table, and the cards are written with numbers from left to right, 0,1,2,3,4,5,6... Now aim the camera at the number 0, and then move to the right at a uniform speed. The numbers pass through the camera's viewfinder and continue to increase. When aiming at the number 5, press the shutter. If it is a triple-camera, the photo obtained will probably show 6, while if it is taken with a single-camera, the photo obtained will be about 9. This means the triple camera can capture photos faster, but why is this the case? Any explanation?
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488
Dec ’24
How to add CIFilter to AVCaptureDeferredPhotoProxy
Hello, I m trying to implement deferred photo processing in my photo capture app. After I take a photo, I pass it through a CIFilter, now with the Deferred Photo Processing where would I pass the resulting photo through the CIFilter? Since there is no way for me to know when the system has finished processing a photo. If I have to do it in my app foreground every time, how do I prevent a scenario, where the user takes a photo, heads straight to the Photos App and sees the image without the filter?
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615
Dec ’24
Crash in Photos framework
Hi This is one of our top crashes. It does not contain any of our code in the stacktrace and we can't reproduce it. Those points make this crash very hard to understand and fix. We know that most of the crashes are happening on iPhone 13 with iOS 18.x.x. Also we see that a lot of cases happen when app goes into background (stacktrace contains -[UIApplication _applicationDidEnterBackground]). 2025-03-04_16-06-00.3670_-0500-6a273c7d5da97f098b5cc24898bb9761dc45208e.crash 2025-03-04_20-21-08.6609_-0500-2c08f640900f8a62c4f8a4f6f2a61feb052e66dd.crash 2025-03-04_20-46-27.7138_+0000-4d7ea89b1b564eda22ca63e708f7ad3909c7b768.crash
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380
Mar ’25
Pictures won't import from iPhone to the Photo app on iMac
Since the OS was recently updated to 18.1.1 on my iPhone 15, I am no longer able to import my pictures into the Photos app on my iMac. I have to mention that my iMac is pretty old and is running OS High Sierra 10.13.6 and is not allowing me to update the OS to a newer version. Anyway, the main error message I get is: "Some items cannot be added to your Photo library because they may be an unrecognizable file format or the file may not contain valid data". Then, for each individual photo that failed to upload, the error message I get reads, "unable to read metadata. The file may be corrupt". However, videos import just fine from my iPhone to iMac. This was not a problem before the recent iPhone update. I tried closing the Photo app and reopening it. I tried restarting my iPhone and iMac but nothing seems to work. Any help would be much appreciated.
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1.8k
Dec ’24
Format of 14-bit RAW bayer data from lower bit camera sensor?
I'm working on an application that uses the iPhone camera for scientific purposes - and, as a result would like to receive sensor data in as unprocessed format as possible. I'm using AVCapturePhotoOutput to take Bayer RAW stills and receiving data in kCVPixelFormatType_14Bayer_RGGB format. However, I'm puzzled as to the content of the bits. I simply demosaic the image by taking each 2x2 square: RG GB and use R, (G+G)/2, B to get 16-bit RGB values - and this indeed works. However, I am puzzled as to the values we are getting as they seem to be approximately in the range 2048 - 16383. The top value is understandable - the maximum that you can fit in 14-bits (as implied by the pixel format type). However we don't seem to be able to get lower than ~2048 no matter how black/dark we make the sensor. I'm aware that the sensor is probably not 14-bits (we're using the iPhone 16e camera) and that maybe this is to do with the way the sensor data is packaged. The Advances in iOS Photography video (https://developer.apple.com/videos/play/wwdc2016/501/) describes it as "10-bit sensor RAW packaged in 14 bits per pixel instead of eight." Is there any documentation describing what is going on here? It's vital for our use that we get as close to the raw camera sensor light readings as possible, so any pointers as to the mapping (e.g. decompanding?) being used would be extremely useful. Many thanks in advance for your help.
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130
May ’25
Significant Uptick in AVCaptureSessionWasInterrupted (Reason 4) Leading to Camera Black Screen and AVError Code -11803
In the latest production release of our iOS app (deployed via the App Store), we’ve observed a significant increase in AVCaptureSessionWasInterrupted notifications where the interruption reason has a rawValue of 4. The session does not automatically recover, even after returning from background or deleting/reinstalling the app. An employee ran into this and was able to get a recording. We see the below error when attempting to take photos. "Error Domain=AVFoundationErrorDomain Code=-11803 \"Cannot Record\" UserInfo={AVErrorRecordingFailureDomainKey=3, NSLocalizedDescription=Cannot Record, NSLocalizedRecoverySuggestion=Try recording again.}", } This interruption causes the camera preview to remain black, and any attempt to capture an image results in a failure with the following error: Some questions from our team: What common system conditions or foreground app behaviors can cause .videoDeviceNotAvailableWithMultipleForegroundApps (reason 4) to become persistent? Our teams under is under the impression the interruption reason 4 is mostly associated with iPad and PiP, but neither of these are true in the logs we see. Is manual recovery of the session required? Is there a recommended strategy to detect that the session is unrecoverable and gracefully notify the user or rebuild the session? Is there an instrument(s) in XCode you would recommend when trying to evaluate the increase in reason 4? Best, Ben
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412
Jun ’25
How to transcode HEIC to JPEG while preserving the ISO 21496-1 gain map
When shooting with an iPhone 15 or later, it’s possible to capture HEIC or JPEG images that include gain map information conforming to the ISO 21496-1 standard. However, during image format transcoding, the HEIC codec is able to preserve the ISO 21496-1 gain map. But when converting from HEIC to JPEG, the gain map is transformed into the Apple Gain Map format instead. Is there any solution to this issue?
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918
Jul ’25