I need to get the metaData from an Image I'm picking via UIImagePickerController.
This is my code:
func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
let image = info[UIImagePickerController.InfoKey.originalImage] as! UIImage
let metaData = info[UIImagePickerController.InfoKey.mediaMetadata] as? [AnyHashable: Any]
print(metaData)
picker.dismiss(animated: true, completion: nil)
}
It works fine, when im picking the Image having .camera as source. But when I use .photoLibrary as source, then metaData is nil. I already read through other questions and tried stuff like
let asset = info[.phAsset] as? PHAsset
print(asset?.creationDate ?? "None")
print(asset?.location ?? "None")
But this also returns nil. I guess the source of the problem is, that the info-Dictionary only returns 4 Keys when picking from .photoLibrary:
UIImagePickerControllerOriginalImage
UIImagePickerControllerMediaType
UIImagePickerControllerImageURL
UIImagePickerControllerReferenceURL
It would be awesome if someone could tell me where my mistake is.
Thanks in advance !
I had the same problem. If the user does not grant access to the photo library first, info[.phAsset] will return nil.
Quote from Apple: "Accessing the photo library always requires explicit permission from the user. The first time your app uses PHAsset, PHCollection, PHAssetCollection, or PHCollectionList methods to fetch content from the library ..."
Thus, you have to call PHPhotoLibrary.requestAuthorization{ ... } before presenting the image picker.
If the user denies the request, info[.phAsset] will also be nil!
This key is valid only when using an image picker whose source type is set to UIImagePickerController.SourceType.camera, and applies only to still images.
The value for this key is an NSDictionary object that contains the metadata of the photo that was just captured. To store the metadata along with the image in the Camera Roll, use the PHAssetChangeRequest class from the Photos framework.
https://developer.apple.com/documentation/uikit/uiimagepickercontroller/infokey/1619147-mediametadata
Related
PHPickerViewController allows access to copies of photo library assets as well as returning PHAssets in the results. To get PHAssets instead of file copies, I do:
let photolibrary = PHPhotoLibrary.shared()
var configuration = PHPickerConfiguration(photoLibrary: photolibrary)
configuration.filter = .videos
configuration.selectionLimit = 0
let picker = PHPickerViewController(configuration: configuration)
picker.delegate = self
self.present(picker, animated: true, completion: nil)
And then,
//MARK:- PHPickerViewController delegate
#available(iOS 14, *)
func picker(_ picker: PHPickerViewController, didFinishPicking results: [PHPickerResult]) {
picker.dismiss(animated: true) {
let identifiers:[String] = results.compactMap(\.assetIdentifier)
let fetchResult = PHAsset.fetchAssets(withLocalIdentifiers: identifiers, options: nil)
NSLog("\(identifiers), \(fetchResult)")
}
}
But the problem is once the photo picker is dismissed, it prompts for Photo Library access which is confusing and since the user anyways implicitly gave access to the selected assets in PHPickerViewController, PHPhotoLibrary should load those assets directly. Is there anyway to avoid the Photo library permission?
Is there anyway to avoid the Photo library permission?
Yes, sort of:
Change PHPickerConfiguration(photoLibrary: photolibrary) to PHPickerConfiguration()
Do not use the assetIdentifier to return to the photo library (it will be nil anyway)
In that case, the user can give you image data but that's all. The picker is out-of-process and no data from the library itself is really coming across, just a mere image that the user has explicitly selected.
However, if your goal really is to return to the photo library and obtain the PHAsset, then you must have permission, as you now are indeed attempting to probe the photo library behind the scenes within your app.
What I do, when my app depends on PHAsset information, is to ask for photo library permission (if needed) before presenting the picker, and I don't present the picker if I can't get permission. So, the user taps a button, I discover we have no permission, I ask for permission, we get it (let's say), and I present the picker (doing the asynchronous dance, because the permission arrives asynchronously). Looks great.
By the way, this is also just as true with UIImagePickerController.
UIImagePickerControllerReferenceURL was deprecated in iOS 11 (even though it's still returned in the info dictionary) and was supposed to be replaced with UIImagePickerControllerPHAsset, but I've yet to get an info dictionary back which contains that key. Since the one is deprecated and the other is missing, is there a known solution for extracting the "date taken" from the picked image?
For reference, this is an example info dictionary returned when and image is picked from the library:
▿ 4 elements
▿ 0 : 2 elements
- key : "UIImagePickerControllerImageURL"
- value : file:///private/var/mobile/Containers/Data/Application/EE1BA60E-2DC3-47C5-A58D-86498E95C323/tmp/3A025D4C-B378-474B-8A09-017479A3A776.jpeg
▿ 1 : 2 elements
- key : "UIImagePickerControllerMediaType"
- value : public.image
▿ 2 : 2 elements
- key : "UIImagePickerControllerReferenceURL"
- value : assets-library://asset/asset.HEIC?id=537976CD-A550-41C9-9416-92C8072112D7&ext=HEIC
▿ 3 : 2 elements
- key : "UIImagePickerControllerOriginalImage"
- value : <UIImage: 0x1d04b4760> size {3024, 4032} orientation 3 scale 1.000000
(Note that UIImagePickerControllerReferenceURL is still present, though deprecated, and the suggested replacement, UIImagePickerControllerPHAsset, is missing.)
If it were present, getting the date would be simple:
if let asset = info[UIImagePickerControllerPHAsset] as? PHAsset,
let resource = PHAssetResource.assetResources(for: asset).first {
let dateTaken = resource.creationDate
}
Could it be that Apple forgot to implement UIImagePickerControllerPHAsset? Any ideas on workarounds (without using deprecated methods)?
Note on possible duplicates
I believe that previous solutions on Stack Overflow are deprecated, and thus won't answer the question using modern approaches.
Swift 4.1
I struggled with this for a while too. It turns out you just need user permission to access to the photo library - then info will contain a value for the key UIImagePickerControllerPHAsset. You can check & request access like this:
let status = PHPhotoLibrary.authorizationStatus()
switch status {
case .authorized:
// show your media picker
case .denied:
// probably alert the user that they need to grant photo access
case .notDetermined:
PHPhotoLibrary.requestAuthorization({status in
if status == .authorized {
// show your media picker
}
})
case .restricted:
// probably alert the user that photo access is restricted
}
Then you use the imagePickerController(_: didFinishPickingMediaWithInfo:) method as usual and will have access to the UIImagePickerControllerPHAsset
You can get the date by examining the chosen photo's metadata through the ImageIO framework.
However, the claim that the PHAsset information doesn't arrive is simply bogus. It arrives just fine. You didn't show your code, so who knows what you're doing? Perhaps the problem is that you forgot to get user authorization? Without user authorization, of course you can't access the PHAsset. You'll get the UIImagePickerControllerOriginalImage and the UIImagePickerControllerImageURL and that's all.
This code works just fine for me (assuming we have the necessary user authorization before using the image picker controller in the first place):
func imagePickerController(_ picker: UIImagePickerController,
didFinishPickingMediaWithInfo info: [String : Any]) { //
let asset = info[UIImagePickerControllerPHAsset] as? PHAsset
let url = info[UIImagePickerControllerMediaURL] as? URL
var im = info[UIImagePickerControllerOriginalImage] as? UIImage
if let ed = info[UIImagePickerControllerEditedImage] as? UIImage {
im = ed
}
let live = info[UIImagePickerControllerLivePhoto] as? PHLivePhoto
let imurl = info[UIImagePickerControllerImageURL] as? URL
self.dismiss(animated:true) {
if let style = asset?.playbackStyle { // and so on, works fine
// ....
}
}
}
I'm working on this app development tutorial:
https://developer.apple.com/library/ios/referencelibrary/GettingStarted/DevelopiOSAppsSwift/Lesson4.html#//apple_ref/doc/uid/TP40015214-CH6-SW1
and I got up to the part where you use the info dictionary (towards the end of the tutorial), but I'm getting the error "use of unresolved identifier 'info'". I copied and pasted the code they provided:
//The info dictionary contains multiple representations of the image,
//and this uses the original.
let selectedImage = info[UIImagePickerControllerOriginalImage] as! UIImage
but it wont work
The code is supposed to be placed in this method:
func imagePickerController(picker: UIImagePickerController,
didFinishPickingMediaWithInfo info: [String : AnyObject]) {
}
info is one of the parameters to the function.
I'm working on an app that uploads a video on a server and I got to a point where I need to re-run the upload process if a user shuts down the app and openes it again later.
After a user taps on a video, this function gets triggered
func imagePickerController(picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : AnyObject]) {
let mediaType = info[UIImagePickerControllerMediaType] as! NSString
if mediaType == kUTTypeMovie {
let fileUrl = info[UIImagePickerControllerMediaURL] as! NSURL
// ...
}
self.performSegueWithIdentifier("someSegue", sender: self)
}
But I found out that fileUrl points to some temporary reference to the original video and is always different even if the video is the same.
So how can I get real path to the video, which I can save to NSUserDefaults so when a user opens the app again I can access the video again.
The UIImagePicker will always compress a video and hands you the NSURL of the temp file given in info[UIImagePickerControllerMediaURL]--and it is your responsibility to delete that temp file whether you use it or not.
If you want to use the compressed version, move it to your documents folder and save the path to that in your NSUserDefaults.
If you want the original raw video, get the NSURL in info[UIImagePickerControllerReferenceURL]. This is the URL to the original ALAsset. Then you'll need to use PHImageManager().requestImageDataForAsset or PHImageManager().requestExportSessionForVideo to get the data for upload.
I'm trying to print all the image metadata in the imagePickerController: didFinishPickingMediaWithInfo function. When I use the info.objectForKey(UIImagePickerControllerReferenceURL) method, it returns nil and if try to use this result my app crashes. Does anyone know why it returns nil and what else can I use to print all the image metadata when I pick an image? (using UIImageJPEGRepresentation is not an option because the EXIF data is removed).
This is my code:
func imagePickerController(picker: UIImagePickerController!, didFinishPickingMediaWithInfo info: NSDictionary!)
{
let image = info.objectForKey(UIImagePickerControllerOriginalImage) as UIImage
let refURL : NSURL = info.objectForKey(UIImagePickerControllerReferenceURL) as NSURL
var localSourceRef: CGImageSourceRef = CGImageSourceCreateWithURL(refURL, nil)
var localMetadata: NSDictionary = CGImageSourceCopyPropertiesAtIndex(localSourceRef, 0, nil)
println("\n Photo data: \n")
println(localMetadata)
}
So it sounds like there are actually two questions here:
1) Why is UIImagePickerControllerReferenceURL returning a nil reference?
2) How can you get location data from the photo?
So, the answer to (1) is usually because you receive the callback didFinishPickingMedia before the OS as written the file to the image library.
The answer to #2 is much trickier, as showcased by this question's line of answers:
Reading the GPS data from the image returned by the camera in iOS iphone
There are a number of variables you need to account for:
iOS will strip the GPS data out if you haven't requested access to location data, so you'll need to prompt for location access using CLLocationManager.
If the user has geotagging disabled, you'll never get GPS coords.
If the phone can't get a GPS lock, iOS won't record the GPS coords.
Per this answer: https://stackoverflow.com/a/10338012/490180 you should be able to retrieve the raw UIImage and then create the CGImageSourceRef from the data property off of UIImage's CGImage. This effectively removes the need for you to ever access the ReferenceURL.