Currently, I am extracting EXIF metadata for PHAsset's that are images, but not having luck with videos.
For images, this works for me:
let imageOptions = PHImageRequestOptions()
imageOptions.isNetworkAccessAllowed = true
imageOptions.isSynchronous = true
imageOptions.version = .current
PHImageManager.default().requestImageDataAndOrientation(for: self.asset!, options: imageOptions) { (data, responseString, orientation, info) in
if let imageData: Data = data {
if let imageSource = CGImageSourceCreateWithData(imageData as CFData, nil) {
let imageProperties = CGImageSourceCopyPropertiesAtIndex(imageSource, 0, nil)! as NSDictionary
}
}
})
What alteration would I need to retrieve metadata for a video asset?
self.asset!.mediaType == .video
UPDATE
After the first answer, I tried studying:
https://developer.apple.com/documentation/avfoundation/media_assets_and_metadata/retrieving_media_metadata
So far, I am still having issues understanding the concept. I tried:
let formatsKey = "availableMetadataFormats"
asset.loadValuesAsynchronously(forKeys: [formatsKey]) {
var error: NSError? = nil
let status = asset.statusOfValue(forKey: formatsKey, error: &error)
if status == .loaded {
for format in asset.availableMetadataFormats {
let metadata = asset.metadata(forFormat: format)
print (metadata)
}
}
}
I wasn't able to extract anything inside PHImageManager.default().requestAVAsset, coming up empty.
What I need is video fps/codec/sound(stereo or mono)/colorspace. That is it. I was able to get somewhere with:
if let videoTrack = asset.tracks(withMediaType: .video).first {
let videoFormatDescription = videoTrack.formatDescriptions.first as! CMVideoFormatDescription
print (videoFormatDescription)
}
Within CMVideoFormatDescription, most of the required attributes seem to be present, yet, I am unable to extract them so far.
Call requestAVAsset(forVideo:options:resultHandler:). Now you have an AVAsset. It has metadata and commonMetadata properties and you’re off to the races.
Related
I am attempting to load photos located on external storage (SD card) using core graphics in iOS 13 (beta). The code below works fine when the files are on the device. When the files are on external storage however it fails returning nil and I don't know why.
I believe I am using the correct security scoping.
I loaded the file URLs from a security scoped folder url as per Providing Access to Directories
guard folderUrl.startAccessingSecurityScopedResource() else {
return nil
}
defer { folderUrl.stopAccessingSecurityScopedResource() }
guard let imageSource = CGImageSourceCreateWithURL(imageURL as CFURL, options) else {
throw Error.failedToOpenImage(message: "Failed to open image at \(imageURL)")
}
So... for my own project, where I ran into the same issue, I now have the following function to give me a thumbnail, going from elegant and quick to brute force.
static func thumbnailForImage(at url: URL, completion: (Result<UIImage, Error>) -> Void) {
let shouldStopAccessing = url.startAccessingSecurityScopedResource()
defer { if shouldStopAccessing { url.stopAccessingSecurityScopedResource() } }
let coordinator = NSFileCoordinator()
var error: NSError?
coordinator.coordinate(readingItemAt: url, options: .withoutChanges, error: &error) { url in
var thumbnailImage: UIImage?
var storedError: NSError?
var imageSource: CGImageSource?
print("Strategy 1: Via URL resource key")
do {
let resourceKeys = Set([URLResourceKey.thumbnailDictionaryKey])
let resources = try url.resourceValues(forKeys: resourceKeys)
if let dict = resources.thumbnailDictionary, let resource = dict[URLThumbnailDictionaryItem.NSThumbnail1024x1024SizeKey] {
thumbnailImage = resource
} else {
throw "No thumbnail dictionary"
}
} catch let error {
storedError = error as NSError
}
let options = [kCGImageSourceCreateThumbnailFromImageIfAbsent: true, kCGImageSourceShouldAllowFloat: true, kCGImageSourceCreateThumbnailWithTransform: true]
if thumbnailImage == nil {
print("Strategy 2: Via CGImageSourceCreateWithURL")
imageSource = CGImageSourceCreateWithURL(url as CFURL, options as CFDictionary)
}
if thumbnailImage == nil && imageSource == nil {
print("Strategy 3: Via CGImageSourceCreateWithData")
let data = try? Data.init(contentsOf: url)
if let data = data {
imageSource = CGImageSourceCreateWithData(data as CFData, options as CFDictionary)
}
}
if let imageSource = imageSource, thumbnailImage == nil {
print("Attempting thumbnail creation from source created in strategy 2 or 3")
if let image = CGImageSourceCreateThumbnailAtIndex(imageSource, 0, options as CFDictionary) {
thumbnailImage = UIImage(cgImage: image)
}
}
if let thumbnailImage = thumbnailImage {
print("Success")
completion(.success(thumbnailImage))
} else {
print("Failure")
if let error = storedError { completion(.failure(error)) }
else { completion(.failure("Everything just fails...")) }
}
}
if let error = error { completion(.failure(error)) }
}
Basically it works by trying to get a thumbnail via the URL resources first. This is the quickest and nicest way, of it works. If that fails, I try CGImageSourceCreateWithURL. That works most of the time, except on remote storage. I suspect that's still a bug and submitted a feedback ticket to apple for this. I suggest you do the same. Last attempt, just try to read the entire file using NSData and creating an image source via CGImageSourceCreateWithData...
So far, if it's an image file I, this seems to produce a thumbnail most of the time. It can be quite slow though, having to read the entire file.
In my app I'm trying to have image data have metadata (location, timestamp etc.). I'm using UIImagePickerController to do image capture, and the delegate function of which has:
info[UIImagePickerController.InfoKey.originalImage]
info[UIImagePickerController.InfoKey.phAsset]
info[UIImagePickerController.InfoKey.mediaMetadata]
So for the images picked from the library .phAsset has everything I need. I just use .getDataFromPHAsset function to get the enriched data. However, for the images that were just taken .phAsset is nil. I thought about trying to somehow combine .originalImage and .mediaMetadata together into single Data object, but can't get the result desired. I tried to use this approach: https://gist.github.com/kwylez/a4b6ec261e52970e1fa5dd4ccfe8898f
I know I can also make custom imageCapture controller, using AVCaptureSession, and use AVCapturePhoto function .fileDataRepresentation() on didFinishProcessingPhoto delegate call, but that's not my first choice.
Any kind of help is highly appreciated.
I'm pretty sure mediaMetadata will not have location info. Use this CLLocation extension.
Then use the function below to add the metadata to the image data:
func addImageProperties(imageData: Data, properties: NSMutableDictionary) -> Data? {
let dict = NSMutableDictionary()
dict[(kCGImagePropertyGPSDictionary as String)] = properties
if let source = CGImageSourceCreateWithData(imageData as CFData, nil) {
if let uti = CGImageSourceGetType(source) {
let destinationData = NSMutableData()
if let destination = CGImageDestinationCreateWithData(destinationData, uti, 1, nil) {
CGImageDestinationAddImageFromSource(destination, source, 0, dict as CFDictionary)
if CGImageDestinationFinalize(destination) == false {
return nil
}
return destinationData as Data
}
}
}
return nil
}
Usage:
if let imageData = image.jpegData(compressionQuality: 1.0), let metadata = locationManager.location?.exifMetadata() {
if let newImageData = addImageProperties(imageData: imageData, properties: metadata) {
// newImageData now contains exif metadata
}
}
I am removing exif and location metadata from images using Photos and image I/O frameworks:
First I get Data from PHAssets:
let manager = PHImageManager()
manager.requestImageData(for: currentAsset, options: options) { (data, dataUTI, orientation, info) in
if let data = data {
dataArray.append(data)
}
}
Then I use this function to remove metadata:
fileprivate func removeMetadataFromData(data: Data) -> NSMutableData? {
guard let source = CGImageSourceCreateWithData(data as CFData, nil) else {return nil}
guard let type = CGImageSourceGetType(source) else {return nil}
let count = CGImageSourceGetCount(source)
let mutableData = NSMutableData(data: data)
guard let destination = CGImageDestinationCreateWithData(mutableData, type, count, nil) else {return nil}
let removeExifProperties: CFDictionary = [String(kCGImagePropertyExifDictionary) : kCFNull, String(kCGImagePropertyGPSDictionary): kCFNull] as CFDictionary
for i in 0..<count {
CGImageDestinationAddImageFromSource(destination, source, i, removeExifProperties)
}
guard CGImageDestinationFinalize(destination) else {return nil}
return mutableData
}
Then I use this to create UIImage from NSMutableData objects that I get from previous function:
let image = UIImage(data: mutableData as Data)
and I save the image to user's library like so:
PHPhotoLibrary.shared().performChanges({
let request = PHAssetChangeRequest.creationRequestForAsset(from: image)
let placeholder = request.placeholderForCreatedAsset
let albumChangeRequest = PHAssetCollectionChangeRequest(for: collection)
if let placeholder = placeholder, let albumChangeRequest = albumChangeRequest {
albumChangeRequest.addAssets([placeholder] as NSArray)
}
return mutableData
}
The problem I have is that using this method, the output file is compressed, and also the name and DPI of the resulting image is different from the original image. I want to keep everything the same as the original image and just remove the metadata. Is there a way to do that?
The problem is the round-trip through UIImage. Just save the Data obtained from requestImageDataAndOrientation.
func saveCopyWithoutLocation(for asset: PHAsset) {
let options = PHImageRequestOptions()
manager.requestImageDataAndOrientation(for: asset, options: options) { data, dataUTI, orientation, info in
guard let data = data else { return }
self.library.performChanges {
let request = PHAssetCreationRequest.forAsset()
request.addResource(with: .photo, data: data, options: nil)
request.location = nil
} completionHandler: { success, error in
if success {
print("successful")
} else {
print(error?.localizedDescription ?? "no error?")
}
}
}
}
Now, that only removes location. If you really want to remove more EXIF data obtained through CGImageSourceCreateWithData, you can do that. But just avoid an unnecessary round-trip through a UIImage. It is the whole purpose to use CGImageSource functions, namely that you can change metadata without changing the underlying image payload. (Round-tripping through UIImage is another way to strip meta data, but as you have discovered, it changes the image payload, too, though often not observable to the naked eye.)
So, if you want, just take the data from CGImageDestination functions directly, and pass that to PHAssetCreationRequest. But I might advise being a little more discriminating about which EXIF metadata you choose to remove, because some of it is important, non-confidential image data (e.g., likely the DPI is in there).
Regarding the filename, I'm not entirely sure you can control that. E.g., I've had images using the above location-stripping routine, and some preserve the file name in the copy, and others do not (and the logic of which applies is not immediately obvious to me; could be the sourceType). Obviously, you can use PHAssetChangeRequest rather than PHAssetCreationRequest, and you can just update the original PHAsset, and that would preserve the file name, but you might not have intended to edit the original asset and may have preferred to make a new copy.
In my App I want to make it possible, that the user sets an StarRating from 0 to 5 for any Image he has in his PhotoLibrary. My research shows, that there are a couple of ways to get this done:
Save the exif metadata using the new PHPhotoLibrary
Swift: Custom camera save modified metadata with image
Writing a Photo with Metadata using Photokit
Most of these Answers were creating a new Photo. My snippet now looks like this:
let options = PHContentEditingInputRequestOptions()
options.isNetworkAccessAllowed = true
self.requestContentEditingInput(with: options, completionHandler: {
(contentEditingInput, _) -> Void in
if contentEditingInput != nil {
if let url = contentEditingInput!.fullSizeImageURL {
if let nsurl = url as? NSURL {
if let imageSource = CGImageSourceCreateWithURL(nsurl, nil) {
var imageProperties = CGImageSourceCopyPropertiesAtIndex(imageSource, 0, nil) as Dictionary?
if imageProperties != nil {
imageProperties![kCGImagePropertyIPTCStarRating] = rating as AnyObject
let imageData = NSMutableData(contentsOf: url)
let image = UIImage(contentsOfFile: url.path)
let destination = CGImageDestinationCreateWithData(imageData!, CGImageSourceGetType(imageSource)!, 1, nil)
CGImageDestinationAddImage(destination!, image!.cgImage!, imageProperties! as CFDictionary)
var contentEditingOutput : PHContentEditingOutput? = nil
if CGImageDestinationFinalize(destination!) {
let archievedData = NSKeyedArchiver.archivedData(withRootObject: rating)
let identifier = "com.example.starrating"
let adjustmentData = PHAdjustmentData(formatIdentifier: identifier, formatVersion: "1.0", data: archievedData)
contentEditingOutput = PHContentEditingOutput(contentEditingInput: contentEditingInput!)
contentEditingOutput!.adjustmentData = adjustmentData
if imageData!.write(to: contentEditingOutput!.renderedContentURL, atomically: true) {
PHPhotoLibrary.shared().performChanges({
let request = PHAssetChangeRequest(for: self)
request.contentEditingOutput = contentEditingOutput
}, completionHandler: {
success, error in
if success && error == nil {
completion(true)
} else {
completion(false)
}
})
}
} else {
completion(false)
}
}
}
}
}
}
})
Now when I want to read the metadata from the PHAsset I request the ContentEditingInput again and do the following:
if let url = contentEditingInput!.fullSizeImageURL {
if let nsurl = url as? NSURL {
if let imageSource = CGImageSourceCreateWithURL(nsurl, nil) {
if let imageProperties = CGImageSourceCopyPropertiesAtIndex(imageSource, 0, nil) as Dictionary? {
if let starRating = imageProperties[kCGImagePropertyIPTCStarRating] as? Int {
rating = starRating
}
}
}
}
}
But I never get my rating because it says that the value of imageProperties[kCGImagePropertyIPTCStarRating] is nil.
I also tried the examples from the Answers I posted above, but I always get the same result.
I hope anybody knows, what I can do to change the Metadata.
Also, how can I change the Metadata from an PHAsset with the MediaType .video? I tried to achieve that through the AVAssetWriter and AVExportSession Objects, but in both cases it does not work. Here what I tried for Videos:
var exportSession = AVAssetExportSession(asset: asset!, presetName: AVAssetExportPresetPassthrough)
exportSession!.outputURL = outputURL
exportSession!.outputFileType = AVFileTypeQuickTimeMovie
exportSession!.timeRange = CMTimeRange(start: start, duration: duration)
var modifiedMetadata = asset!.metadata
let metadataItem = AVMutableMetadataItem()
metadataItem.keySpace = AVMetadataKeySpaceQuickTimeMetadata
metadataItem.key = AVMetadataQuickTimeMetadataKeyRatingUser as NSCopying & NSObjectProtocol
metadataItem.value = rating as NSCopying & NSObjectProtocol
modifiedMetadata.append(metadataItem)
exportSession!.metadata = modifiedMetadata
exportSession!.exportAsynchronously(completionHandler: {
let status = exportSession?.status
let success = status == AVAssetExportSessionStatus.completed
if success {
do {
let sourceURL = urlAsset.url
let manager = FileManager.default
_ = try manager.removeItem(at: sourceURL)
_ = try manager.moveItem(at: outputURL, to: sourceURL)
} catch {
LogError("\(error)")
completion(false)
}
} else {
LogError("\(exportSession!.error!)")
completion(false)
}
})
Sorry this isn't a full answer but it covers one part of your question. I noticed you are placing the StarRating in the wrong place. You need to place it in a IPTC dictionary. Also the properties data is stored as strings. Given you have the imageProperties you can add the star rating as follows and read it back using the following two functions
func setIPTCStarRating(imageProperties : NSMutableDictionary, rating : Int) {
if let iptc = imageProperties[kCGImagePropertyIPTCDictionary] as? NSMutableDictionary {
iptc[kCGImagePropertyIPTCStarRating] = String(rating)
} else {
let iptc = NSMutableDictionary()
iptc[kCGImagePropertyIPTCStarRating] = String(rating)
imageProperties[kCGImagePropertyIPTCDictionary] = iptc
}
}
func getIPTCStarRating(imageProperties : NSMutableDictionary) -> Int? {
if let iptc = imageProperties[kCGImagePropertyIPTCDictionary] as? NSDictionary {
if let starRating = iptc[kCGImagePropertyIPTCStarRating] as? String {
return Int(starRating)
}
}
return nil
}
As the imageProperties you get from the image are not mutable you need to create a mutable copy of these properties first before you can call the functions above. When you create your image to save use the mutable properties in your call to CGImageDestinationAddImage()
if let mutableProperties = imageProperties.mutableCopy() as? NSMutableDictionary {
setIPTCStarRating(imageProperties:mutableProperties, rating:rating)
}
One other point you are creating an unnecessary UIImage. If you use CGImageDestinationAddImageFromSource() instead of CGImageDestinationAddImage() you can use the imageSource you created earlier instead of loading the image data into a UIImage.
I want to display image metadata using UIImagePickerController in Swift.
where the image is been selected from gallery and would be displayed in the imageView along with the meta data such as PixelHeight,PixelWidth,PixelXDimension,PixelYDimension,Coordinates,Size,Date Created and Imagename.
At first, you can get info[UIImagePickerControllerReferenceURL] from UIImagePickerController. Then you can do things like the following:
let assetURL = info[UIImagePickerControllerReferenceURL] as! NSURL
let asset = PHAsset.fetchAssetsWithALAssetURLs([assetURL], options: nil)
guard let result = asset.firstObject where result is PHAsset else {
return
}
let imageManager = PHImageManager.defaultManager()
imageManager.requestImageDataForAsset(result as! PHAsset, options: nil, resultHandler:{
(data, responseString, imageOriet, info) -> Void in
let imageData: NSData = data!
if let imageSource = CGImageSourceCreateWithData(imageData, nil) {
let imageProperties = CGImageSourceCopyPropertiesAtIndex(imageSource, 0, nil)! as NSDictionary
//now you have got meta data in imageProperties, you can display PixelHeight, PixelWidth, etc.
}
})