Recently Apple gave us the possibility to upload asset resources in the background. We implemented our background upload extension but when our CI tried to upload the app on TestFlight we got an error that the extension point identifier - in our case com.apple.photos.backgound-upload - is not an official one. Any idea when it will become official and we will be able to release a working background uploading?
Photos & Camera
RSS for tagExplore technical aspects of capturing high-quality photos and videos, including exposure control, focus modes, and RAW capture options.
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Hi,
I’m trying to implement the new PhotoKit PHBackgroundResourceUploadExtension. I created the extension, enabled full photo library access in the host app, and registered the extension point using the string: com.apple.photos.background-upload.
However, when I attempted to enable the extension with:
try library.setUploadJobExtensionEnabled(true)
I received the following error:
Error Domain=PHPhotosErrorDomain Code=-1 "(null)"
This happens when running the app on Xcode 26.1 and 26.2 Beta, using the iPhone 17 Pro Max simulator (iOS 26.1 and 26.2).
My question is: Is this extension supported on the simulator?
I’m asking because at the moment it’s difficult for me to test this on a physical device.
Also, What's the meaning of the error?
Thanks.
I'm trying to benchmark a Core Image filter chains memory footprint and notice a weird quirk in instruments.
On a real device, even with a simple Core Image chain, the memory balloons each time I ran the filter. See attached screen shots.
Running on iPhone 17 Pro:
Running on simulator (M2 Macbook Pro)
As you can see there's a huge build up of 4MB "VM: IOSurface" memory on the real device, but the simulator seems to clean it up correctly.
Here's my basic code:
func processImage() {
guard let inputImage = ContentViewModel.loadImageFromBundle(name: "kitty.HEIC") else {
print("Failed to load sample_image from bundle")
return
}
var outputImage = inputImage
outputImage = outputImage.applyingFilter("CIBloom", parameters: [
kCIInputRadiusKey: 20,
kCIInputIntensityKey: 0.8
])
DispatchQueue.global(qos: .userInitiated).async {
let data = self.context.jpegRepresentation(of: outputImage, colorSpace: CGColorSpace(name: CGColorSpace.sRGB)!)
if let data = data, let uiImage = UIImage(data: data) {
DispatchQueue.main.async {
self.displayImage = Image(uiImage: uiImage)
}
}
}
}
Why is this happening? Seems like a bug to me or I need to release an object. At the very least makes it challenging to measure memory usage.
Any help is greatly appreciated.
Alex
Device: iPhone 17 Pro
iOS Version: iOS 26.1
Camera: Ultra-wide (0.5x) using AVCaptureSession
Our camera app freezes on iPhone 17 when switching frame rates (30fps ↔ 60fps). This works fine on iPhone 16 Pro and earlier.
What We've Observed:
Freeze happens on frame rate change - particularly when stabilization was enabled
Thread.sleep is used - to allow camera hardware to settle before re-enabling stabilization
Works on older iPhones - only iPhone 17 exhibits this behavior
Console shows these errors before freeze:
17281
<<<< FigXPCUtilities >>>> signalled err=18446744073709534335 <<<< FigCaptureSourceRemote >>>> err=-17281
Is Thread.sleep on the main thread causing the freeze? Should all camera configuration be on a background queue?
Is there something specific about iPhone 17 ultra-wide camera that requires different handling?
Should we use session.beginConfiguration() / session.commitConfiguration() instead of direct device configuration?
Is calling setFrameRate from a property's didSet (which runs synchronously) problematic?
Are the FigCaptureSourceRemote errors (-17281) indicative of the problem, and what do they mean?
PHPhotoLibrary.authorizationStatus(for: .readWrite) == .authorized
Iinfo.plist Privacy - Photo Library Usage Description set
I check authorization before attempting to get the photoPickerItem.itemIdentifier, but every time the return value from itemIdentifier is nil. Seems I missing some permissions, but unsure why the system is still keeping _shouldExposeItemIdentifier set to false.
Topic:
Media Technologies
SubTopic:
Photos & Camera
I am new to Swift and iOS development, and I have a question about video capture performance.
Is it possible to capture video at a resolution of 4032×3024 while simultaneously running a vision/ML model on the video stream (e.g., using Vision or CoreML)?
I want to know:
whether iOS devices support capturing video at that resolution,
whether the frame rate drops significantly at that scale,
and whether it is practical to run a Vision/ML model in real-time while recording at such a high resolution.
If anyone has experience with high-resolution AVCaptureSession setups or combining them with real-time ML processing, I would really appreciate guidance or sample code.
I'm adopting Liquid Glass in iOS 26, when I try to test VNDocumentCameraViewController with document scanning after Liquid Glass enabled, there's a crash just after a photo is taken in VNDocumentCameraViewController, here's the screenshot when it crashed
The exception output in XCode console is this:
*** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Layout requested for visible navigation bar, <UINavigationBar: 0x1240bde00; frame = (0 117; 390 54); opaque = NO; tintColor = UIExtendedSRGBColorSpace 1 1 0 1; layer = <CALayer: 0x120c21e60>> standardAppearance=0x12407b900 scrollEdgeAppearance=0x12407bb80 compactAppearance=0x12407b880 no-scroll-edge-support, when the top item belongs to a different navigation bar. topItem = <UINavigationItem: 0x1240bd800> style=navigator leftBarButtonItems=0x123d4e5f0 rightBarButtonItems=0x123d4d5a0, navigation bar = <UINavigationBar: 0x107b9ad00; frame = (0 47; 390 54); opaque = NO; autoresize = W; tintColor = UIExtendedSRGBColorSpace 1 1 0 1; layer = <CALayer: 0x120c20150>> delegate=0x10a805200 standardAppearance=0x107b2c300 scrollEdgeAppearance=0x107b2c280 compactAppearance=0x107b2c100, possibly from a client attempt to nest wrapped navigation controllers.'
*** First throw call stack:
(0x18e1db994 0x18b0f5814 0x18c092aa0 0x193b18660 0x193a7d540 0x193a7e020 0x1953ec4a0 0x1943b7d78 0x18ed83420 0x18ed82f74 0x18eb83134 0x18eb44c10 0x18eb70bc4 0x18eb7e74c 0x193ac8cd0 0x193ac8c04 0x193ad6afc 0x193ad5f8c 0x27b456560 0x18e12c4cc 0x18e15c0b0 0x18e15bfd8 0x18e133c1c 0x18e132a6c 0x22ed54498 0x193af6ba4 0x193a9fa78 0x193bcb68c 0x102cc2718 0x102cc2688 0x102cc2794 0x18b14ae28)
libc++abi: terminating due to uncaught exception of type NSException
I’m writing to report a serious usability regression in the iOS 26 Photos app. Folders can still be created and albums can still be assigned to them, but folders can no longer be opened to view the albums they contain. A container that cannot be opened is not a container, and this breaks a fundamental information architecture model that has existed in Photos for well over a decade.
This change disproportionately harms users who maintain large, intentional photo libraries—travel archives, projects, professional work, or long-term personal documentation—where hierarchy and ordering are essential. Search and automated surfacing are not substitutes for deliberate structure. Removing the ability to browse folder → album hierarchy on iOS strips users of control while still exposing the UI for folder creation, which is internally inconsistent.
If this behavior is intentional, it should be clearly documented and the folder UI removed to avoid misleading users. If it is not intentional, it needs urgent correction. At minimum, iOS should retain parity with macOS Photos for basic navigation of folders and albums. This is not a niche request; it is a regression in core functionality.
Topic:
Media Technologies
SubTopic:
Photos & Camera
Environment
Device: iPhone 15 Pro
iOS: iOS 18.0
Framework: AVFoundation
App type: Custom camera app using AVCaptureSession + AVCaptureVideoPreviewLayer
I’m seeing an intermittent but frequent issue where the camera preview layer briefly flashes empty after certain interruptions, even though the capture session reports itself as running and no errors are emitted.
This happens most often after:
Locking and unlocking the device
Switching cameras (back ↔ front)
The issue is not 100% reproducible, but occurs often enough to be noticeable in normal usage.
What happens
The preview layer briefly flashes as empty (sometimes just a “micro-frame”)
Duration: typically ~0.5–2 seconds before frames resume
session.isRunning == true throughout
No crash, no runtime error, no interruption end failure
Focus/exposure restore correctly once frames resume
Visually it looks like the preview layer loses frames temporarily, even though the session appears healthy.
Repro
Intermittent but frequent after:
Lock → unlock device
Switching camera (front/back)
Timing-dependent and non-deterministic
Happens multiple times per session, but not every time
Key observation
AVCaptureSession.isRunning == true does not guarantee that frames are actually flowing.
To verify this, I added an AVCaptureVideoDataOutput temporarily:
During the blank period, no sample buffers are delivered
Frames resume after ~1–2s without any explicit restart
Session state remains “running” the entire time
What I’ve tried (did NOT fix it)
Adding delays before/after startRunning() (0.1–0.5s)
Calling startRunning() on different queues
Restarting the session in AVCaptureSessionInterruptionEnded
Verifying session.connections (all show isActive == true)
Rebuilding inputs/outputs during interruption recovery
Ensuring startRunning() is never called between beginConfiguration() / commitConfiguration()
(Hit the expected runtime warning when attempted)
None of the above removed the brief blank preview.
Workaround (works visually but expensive)
This visually fixes the issue, but:
Energy impact jumps from Low → High in Xcode Energy Gauge
AVCaptureVideoDataOutput processes 30–60 FPS continuously
The gap only lasts ~1–2s, but toggling the delegate on/off cleanly is difficult
Overall CPU and energy cost is not acceptable for production
Additional notes
CPU usage is already relatively high even without the workaround (this app is camera-heavy by nature)
With the workaround enabled, energy impact becomes noticeably worse
The issue feels like a timing/state desync between session state and actual frame delivery, not a UI issue
Questions
Is this a known behavior where AVCaptureSession.isRunning == true but frames are temporarily unavailable after interruptions?
Is there a recommended way to detect actual frame flow resumption (not just session state)?
Should the AVCaptureVideoPreviewLayer.connection (isActive / isEnabled) be explicitly checked or reset after interruptions?
Is there a lightweight, energy-efficient way to bridge this short “no frames” gap without using AVCaptureVideoDataOutput?
Is rebuilding the entire session the only reliable solution here, or is there a better pattern Apple recommends?
We have a very strange issue that I am trying to solve or find the best practice for.
We have a SwiftUI View that uses the Camera to preview. So as suggested in Apples Docs we check authorisation status and then if it's not determined we request authorisation.
We also have the privacy entry in the info.plist
case .notDetermined:
AVCaptureDevice.requestAccess(for: .video) { accessStatusAuthorised in
if !accessStatusAuthorised {
self.cameraStatus = .notAuthorised
} else {
self.isAuthorized = true
self.cameraStatus = .authorised
self.startCameraSession(cameraPosition: cameraPosition)
}
}
case .restricted:
cameraStatus = .notAuthorised
isAuthorized = false
case .denied:
cameraStatus = .notAuthorised
isAuthorized = false
case .authorized:
cameraStatus = .authorised
isAuthorized = true
startCameraSession(cameraPosition: cameraPosition)
break
@unknown default:
isAuthorized = true
cameraStatus = .notAuthorised
}
However when we call this code it freezes the Camera feed, even when allow has been tapped.
However and this is the confusing part.
If we do not call the code above, we still get the permission for camera access pop up and the camera works fine after allowing.
What im concerned about is changing the code to do this and its a possible apple bug that gets fixed and hey then none of the Apps allow the camera function.
I cannot see any where that the process has changed for iOS 26 / Xcode 26.
Can anyone shed any light on this or had similar experience ?
Looking to implement to UI to tell the user to clean their lens in our app.
Implemented the KVO for the cameraLensSmudgeDetectionStatus but I'm having issues reliably triggering it in, both in our app and the main camera app. Tried to get inventive by putting tupperware over the lens, but I think the model driving this or the LiDAR sensor might be smart enough to detect there is something close to the lens.
Is there any way to trigger this change in a similar way we can trigger thermal changes in debug?
Thanks.
I have an iPad app that I want to run on Apple Silicon macs.
Everything works fine except for VNDocumentCameraViewController. According to the docs this class is available on:
iOS 13.0+ iPadOS 13.0+ Mac Catalyst 13.1+ visionOS 1.0+
yet when I try using it I get Document camera is not available on my Mac Studio running macOS 15.2
Is this expected behaviour?
Thanks
am new to using Swift for a Mac Application. I am trying to control an external UVC-compliant camera focus and other capabilities. However, I'm having trouble with this and don't know where to start. I have downloaded an application from the App Store and it can control the focus and other capabilities.
I've tried IOKit but this seems to be complicated and this does not return any capabilities or control the camera.
I also tried AVfoundation and was able to open the camera, but using the following code did not work for me. as a device.isFocusPointOfInterestSupported returns false and without checking the app crashes.
@IBAction func focusChanged(_ sender: NSSlider) {
do {
guard let device = videoDevice else { return }
try device.lockForConfiguration()
// Check if focus mode and point of interest are supported
if device.isFocusModeSupported(.locked) {
device.focusMode = .locked
}
if device.isFocusPointOfInterestSupported {
// Map the slider value (0.0 to 1.0) to the focus point's X coordinate
let focusX = CGFloat(sender.doubleValue)
let focusPoint = CGPoint(x: focusX, y: 0.5) // Y coordinate is typically 0.5 (centered vertically)
device.focusPointOfInterest = focusPoint
} else {
print("Focus point of interest is not supported on this device.")
}
device.unlockForConfiguration()
// Log focus settings
print("Focus point: \(device.focusPointOfInterest)")
print("Focus mode: \(device.focusMode.rawValue)")
} catch {
print("Error adjusting focus: \(error)")
}
Any help or advice is much appreciated.
How can I implement the same custom CIFilter as a Lightroom Color Grading tool for shadows, midtones, highlights and global areas?
Dear Apple Developer Forum,
I have a question regarding the AVCaptureDevice on iOS. We're trying to capture photos in the best quality possible along with depth data with the highest accuracy possible. We were delighted when we saw AVCaptureDevice could be initialized with the AVMediaType=.depthData which works as expected (depthData is a part of the AVCapturePhoto). When setting to AVMediaType=.video, we still receive depth data (of same quality according to our own internal tests). That confused us.
Mind you, we set the device format and depth format as well:
private func getDeviceFormat() throws -> AVCaptureDevice.Format {
// Ensures high video format and an appropriate color profile.
let format = camera?.formats.first(where: {
$0.isHighPhotoQualitySupported &&
$0.supportedDepthDataFormats.count > 0 &&
$0.formatDescription.mediaSubType.rawValue == kCVPixelFormatType_420YpCbCr8BiPlanarFullRange
})
// Check and see if it's available.
guard format != nil else {
throw CaptureDeviceError.necessaryFormatNotAvailable
}
return format!
}
private func getDepthDataFormat(for format: AVCaptureDevice.Format) throws -> AVCaptureDevice.Format {
// Access the depth format.
let depthDataFormat = format.supportedDepthDataFormats.first(where: {
$0.formatDescription.mediaSubType.rawValue == kCVPixelFormatType_DepthFloat32
})
// Check if it exists
guard depthDataFormat != nil else {
throw CaptureDeviceError.necessaryFormatNotAvailable
}
// Returns it.
return depthDataFormat!
}
We're wondering, what steps we can take to ensure the best quality photo, along with the most accurate depth data? What properties are the most important, which have an effect, which don't? Are there any ways we can optimize our current configuration? We find it difficult as there's very limited guides and explanations on the media subtypes, for example kCVPixelFormatType_420YpCbCr8BiPlanarFullRange. Is it the best? Is it the best for our use case of high quality photo + most accurate depth data?
Important comment: Our App only runs on iPhone 14 Pro, iPhone 15 Pro, iPhone 16 Pro on the latest iOS versions.
We hope someone with greater knowledge at Apple can help us and guide us on how we can have the photos of best quality and depth data with most accuracy.
Thank you very much!
Kind regards.
We are encountering a critical, intermittently occurring crash issue when accessing photo data using PHAssetResourceManager.writeDataForAssetResource on iOS 18. The problem does not arise on iOS 17 or earlier versions.
We have been unable to identify a consistent reproduction path. Based on user feedback, the issue seems to involve Live Photo and Raw image files.
Our investigation has revealed that the crash occurs in the +[PISchema identifier] method of the PhotoImaging Framework. When called manually, this method causes a crash on iOS 18 but works without issues on iOS 17.
Reproduction Steps:
1.Fetch PHAsset.
2.Get PHAssetResource by [PHAssetResource assetResourcesForAsset:].
3.Call [PHAssetResourceManager writeDataForAssetResource:toFile:options:completionHandler:].
Crash Log:
Incident Identifier: CFD60092-FDB1-43B4-BA42-3F507F7B8B96
CrashReporter Key: 260b4780989083a54e0cb451930fe9a3bed64862
Hardware Model: iPhone13,4
AppStoreTools: 16C5031b
AppVariant: 1:iPhone13,4:18
Code Type: ARM-64 (Native)
Role: Foreground
Parent Process: launchd [1]
Date/Time: 2025-02-15 19:07:57.7054 +0800
Launch Time: 2025-02-15 19:07:55.4106 +0800
OS Version: iPhone OS 18.3.1 (22D72)
Release Type: User
Baseband Version: 5.20.03
Report Version: 104
Exception Type: EXC_CRASH (SIGABRT)
Exception Codes: 0x0000000000000000, 0x0000000000000000
Termination Reason: SIGNAL 6 Abort trap: 6
Terminating Process: mCloud_iPhone [11109]
Triggered by Thread: 11
Application Specific Information:
abort() called
Thread 11 name: Dispatch queue: com.apple.NSXPCConnection.m-user.com.apple.photos.service
Thread 11 Crashed:
0 libsystem_kernel.dylib 0x1e850b2d4 __pthread_kill + 8
1 libsystem_pthread.dylib 0x221b4959c pthread_kill + 268
2 libsystem_c.dylib 0x19ec24b08 abort + 128
3 NeutrinoCore 0x1bdcdbdec -[NUAssertionPolicyAbort notifyAssertion:] + 68
4 NeutrinoCore 0x1bdcdbbf4 -[NUAssertionPolicyComposite notifyAssertion:] + 160
5 NeutrinoCore 0x1bdcdc098 -[NUAssertionPolicyUnique notifyAssertion:] + 176
6 NeutrinoCore 0x1bdcdb524 -[NUAssertionHandler handleFailureInFunction:file:lineNumber:currentlyExecutingJobName:description:arguments:] + 156
7 NeutrinoCore 0x1bdcdc4bc _NUAssertFailHandler + 176
8 NeutrinoCore 0x1bdc8ea98 -[NUIdentifier initWithNamespace:name:version:] + 2352
9 NeutrinoCore 0x1bdc8eba8 -[NUIdentifier initWithName:version:] + 84
10 NeutrinoCore 0x1bdc8ec10 -[NUIdentifier initWithName:] + 68
11 PhotoImaging 0x1bda54ce4 +[PISchema identifier] + 36
12 PhotoImaging 0x1bda550fc +[PISchema registeredPhotosSchemaIdentifier] + 32
13 PhotoImaging 0x1bd9d7128 +[PIPhotoEditHelper newComposition] + 28
14 PhotoImaging 0x1bd940798 +[PICompositionSerializer deserializeCompositionFromAdjustments:metadata:formatIdentifier:formatVersion:sidecarData:error:] + 160
15 PhotoImaging 0x1bd9412ec +[PICompositionSerializer deserializeCompositionFromData:formatIdentifier:formatVersion:sidecarData:error:] + 224
16 PhotoLibraryServices 0x1afabf75c -[PLPhotoEditPersistenceManager loadCompositionFrom:formatIdentifier:formatVersion:sidecarData:error:] + 1856
17 PhotoLibraryServices 0x1afabffe4 +[PLPhotoEditPersistenceManager validateAdjustmentData:formatIdentifier:formatVersion:error:] + 108
18 Photos 0x1af4ac360 __167+[PHContentEditingInputRequestContext contentEditingInputRequestContextForAsset:requestID:managerID:networkAccessAllowed:downloadIntent:progressHandler:resultHandler:]_block_invoke + 260
19 Photos 0x1af4ac67c -[PHAdjustmentData(ContentEditingInput) _contentEditing_readableByClientWithVerificationBlock:] + 136
20 Photos 0x1af4ac4b0 -[PHAdjustmentData(ContentEditingInput) _contentEditing_requiredBaseVersionReadableByClient:verificationBlock:] + 88
21 Photos 0x1af4abb8c -[PHContentEditingInputRequestContext _adjustmentBaseVersionFromResult:request:canHandleAdjustmentData:] + 404
22 Photos 0x1af4a911c -[PHContentEditingInputRequestContext produceChildRequestsForRequest:reportingIsLocallyAvailable:isDegraded:result:] + 624
23 Photos 0x1af2c1d10 -[PHMediaRequestContext _produceChildRequestsForRequest:withResult:] + 88
24 Photos 0x1af2c11e8 -[PHMediaRequestContext mediaRequest:didFinishWithResult:] + 88
25 Photos 0x1af505184 -[PHAdjustmentDataRequest _finishFromAsynchronousCallback] + 124
26 Photos 0x1af5050a0 __39-[PHAdjustmentDataRequest startRequest]_block_invoke + 584
27 PhotoLibraryServicesCore 0x1b001be8c __106-[PLAssetsdResourceClient adjustmentDataForAsset:networkAccessAllowed:trackCPLDownload:completionHandler:]_block_invoke.86 + 864
28 CoreFoundation 0x196dd8e34 __invoking___ + 148
29 CoreFoundation 0x196dd7e7c -[NSInvocation invoke] + 428
30 Foundation 0x195a64ae0 __NSXPCCONNECTION_IS_CALLING_OUT_TO_EXPORTED_OBJECT__ + 16
31 Foundation 0x195a63514 -[NSXPCConnection _decodeAndInvokeReplyBlockWithEvent:sequence:replyInfo:] + 532
32 Foundation 0x195a6653c __88-[NSXPCConnection _sendInvocation:orArguments:count:methodSignature:selector:withProxy:]_block_invoke_5 + 188
33 libxpc.dylib 0x221babb80 _xpc_connection_reply_callout + 116
34 libxpc.dylib 0x221b9e2d0 _xpc_connection_call_reply_async + 80
35 libdispatch.dylib 0x19eb6b028 _dispatch_client_callout3 + 20
36 libdispatch.dylib 0x19eb88b64 _dispatch_mach_msg_async_reply_invoke + 340
37 libdispatch.dylib 0x19eb7242c _dispatch_lane_serial_drain + 352
38 libdispatch.dylib 0x19eb73158 _dispatch_lane_invoke + 432
39 libdispatch.dylib 0x19eb7e38c _dispatch_root_queue_drain_deferred_wlh + 288
40 libdispatch.dylib 0x19eb7dbd8 _dispatch_workloop_worker_thread + 540
41 libsystem_pthread.dylib 0x221b44680 _pthread_wqthread + 288
42 libsystem_pthread.dylib 0x221b42474 start_wqthread + 8
Topic:
Media Technologies
SubTopic:
Photos & Camera
Hello, my company is developing a product that will send data to/from the phone over cable and Wi-Fi. I have three questions:
Do we need an MFi authentication chip in our product if we plan to send video and commands to the iPhone/iPad over USB or Lightning cable?
Likewise, do we need an MFI authentication chip for communication over Wi-Fi? (Informal research suggests that the answer is no to this one.)
And, do we even still need MFI certification at all for Wi-Fi comms? (We are not using HomeKit.)
Thank you!
Topic:
Media Technologies
SubTopic:
Photos & Camera
I am writing an iOS app to present a slide show of assets in a Photo album, in a random order, including videos and live photos. I have got it all working quite nicely but for a Live Photo, I need to know what effect is selected (Live, Loop, Bounce, Long Exposure, Live Off) to display the image correctly. I can't find any mention of getting this information in the documentation. Anyone know how to do this? Thanks in advance.
Adrian.
(Xcode 16.1 iOS 18.0)
Topic:
Media Technologies
SubTopic:
Photos & Camera
Hi,
Currently I am developing a 3D reconstruction project.
Which requires images to be distortion-free (rectilinear) and with known intrinsics.
The session I am developing on is a builtInDualWideCamera, with isGeometricDistortionCorrectionEnabled set to false to be able to get the intrinsic matrix of the images, isVirtualDeviceConstituentPhotoDeliveryEnabled set to true and isAutoVirtualDeviceFusionEnabled set to false to get both images and isCameraCalibrationDataDeliveryEnabled set to true to actually get the calibration data.
The distortion correction parameters such as lensDistortionLookupTable are used.
The 42 coefficients mapping array is used as described in the AVCameraCalibrationData header file. A simple piecewise linear interpolation.
There are two questions I would like to get support on:
A way to set the calibration parameters in each image.
I have an approach that sets the parameters in the kCGImagePropertyExifDictionary -> "UserComment". Is there a better approach to write calibration parameter data into the images? I feel like this is a bit dirty and there might be a better and neat approach.
For the ultra-wide angle camera's images, the lensDistortionLookupTable contains several zeros at the end of the array.
For example (last 10 elements are zero):
"LensDistortionLookupTable":"0.000000000000000,0.000349554029526,0.001385628827848,0.003071037586778,... ,0.000000000000000,0.000000000000000,0.000000000000000,0.000000000000000,0.000000000000000,0.000000000000000,0.000000000000000,0.000000000000000,0.000000000000000,0.000000000000000"
The problem comes when the complete array is used to correct the image (including zeros), the end result is a wrapped-like-circle image close to the edges of it which is completely wrong.
In contrast, if the LensDistortionLookupTable is used without the last zeros and the new size accommodated the image looks better (although not as rectilinear as if you take the image from the iPhone's camera app), but definitely less distorted.
Including zeros (full array):
Excluding zeros (array size changed):
Am I missing an important point in the usage of the lensDistortionLookupTable where this case is addressed (zeros at the end)?
What is the criteria to shrink/exclude elements of the array?
Any advice is very much welcome.
Is it possible to use the AVExternalStorageDevice to access external storage from a connected camera or usb drive (via USB C or Lightning connector) on an iPad/iPhone.
I have tested the following code on an iPhone 14 (iOS 18.1.1) and an iPad Gen 10 (18.3.1), and both return false for:
// returns false on iPhone 14, iPad gen 10
print(AVExternalStorageDeviceDiscoverySession.isSupported)
The following code returns null, when I try to access the external storage discovery session.
// returns null on iOS devices
print(AVExternalStorageDeviceDiscoverySession.shared)
The following returns false, without displaying a permission dialog:
AVExternalStorageDevice.requestAccess(completionHandler: { (granted: Bool) in
// returns false with no permission dialog
print(granted);
What type of iOS devices are supported by AVExternalStorageDeviceDiscoverySession?
What situations has it been used for (e.g. connecting to Camera via the external storage protocol, accessing photos from a SD card with an adapter, accessing photos from usb drive).
Is there are sample code for using the AV External Storage api?