Saving CIImage with Depth data with writeJPEGRepresentation function - ios

I have a portrait image with depth data with it and after some processing, I want to save a copy of it to a user photo album with depth data preserved (UIImage not an option in this case). For this task, I am using the function writeJPEGRepresentation() which seems to successfully save the modified image with the depth info to somewhere; however, it does not show up on the photo album.
In order it to appear on the photo album, I when try performChanges() function of PHPhotoLibrary,
this time it appeared on the album, but not the modified but the original one!?
Any help highly appreciated. Thanks.
Here is the code:
func saveWithDepth(image : CIImage) {
do {
let colorSpace = CGColorSpace(name: CGColorSpace.sRGB)
let depthdata = DepthData
let url = Url
try Context.writeJPEGRepresentation(of: image, to: url!, colorSpace: colorSpace!,
options: [CIImageRepresentationOption.avDepthData :depthdata!])
PHPhotoLibrary.shared().performChanges({
let options = PHAssetResourceCreationOptions()
let creationRequest = PHAssetCreationRequest.forAsset()
creationRequest.addResource(with: .alternatePhoto, fileURL: url!, options: options)
}, completionHandler: { success, error in
if !success {
print("AVCam couldn't save the movie to your photo library: \(String(describing: error))")
}
})
} catch {
print("failed")
}
}

I think the problem is that JPEG can't store depth data (as far as I know). HEIF would be the format you should use for that. Maybe you can try something like this:
func saveWithDepth(image: CIImage) {
let colorSpace = CGColorSpace(name: CGColorSpace.sRGB)
let depthdata: DepthData
let imageData = context.heifRepresentation(of: image, format: .BGRA8, colorSpace: colorSpace!,
options: [CIImageRepresentationOption.avDepthData: depthdata!])
PHPhotoLibrary.shared().performChanges({
let options = PHAssetResourceCreationOptions()
let creationRequest = PHAssetCreationRequest.forAsset()
creationRequest.addResource(with: .photo, data: imageData, options: options)
}, completionHandler: { success, error in
if !success {
print("Couldn't save the photo to your photo library: \(String(describing: error))")
}
})
}
A few remarks:
I assume depthdata is actually a meaningful value?
You can create and later pass the image data directly to the creationRequest. Then you don't need to save a file to some intermediate location (which you would need to delete afterward).

Related

Saving Data as UIImage while preserving the original image characteristics

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.

Capture Filtered Image with GPUImage and Save to Photo Library with Metadata

I am developing a simple came app for iOS 10. I need to live filter a camera feed, and then capture and save the filtered image.
Using GPUImage, I have been able to setup the live feed and the image capture using GPUImageStillCamera. I am also using the PHPhotoLibrary APIs:
func saveToPhotoLibrary(data: Data, completion: #escaping (PHAsset?) -> ()) {
var assetIdentifier: String?
PHPhotoLibrary.requestAuthorization { (status) in
if status == .authorized {
PHPhotoLibrary.shared().performChanges({
let creationRequest = PHAssetCreationRequest.forAsset()
let placeholder = creationRequest.placeholderForCreatedAsset
creationRequest.addResource(with: .photo, data: data, options: .none)
assetIdentifier = placeholder?.localIdentifier
}, completionHandler: { (success, error) in
if let error = error {
print("There was an error saving to the photo library: \(error)")
}
var asset: PHAsset? = .none
if let assetIdentifier = assetIdentifier {
asset = PHAsset.fetchAssets(withLocalIdentifiers: [assetIdentifier], options: .none).firstObject
}
completion(asset)
})
} else {
print("Need authorisation to write to the photo library")
completion(.none)
}
}
}
The problem is that when this image gets saved, the metadata (such as camera and device information) is missing. How can I save this image with the filter, yet still retain the image metadata?

How to get URL from UIImage?

I have an iOS app in which there are 2 ways the user can get a picture:
Select it from photos library (UIImagePickerController)
Click it from a custom made camera
Here is my code for clicking the image from a custom camera (this is within a custom class called Camera, which is a subclass of UIView)
func clickPicture(completion:#escaping (UIImage) -> Void) {
guard let videoConnection = stillImageOutput?.connection(withMediaType: AVMediaTypeVideo) else { return }
videoConnection.videoOrientation = .portrait
stillImageOutput?.captureStillImageAsynchronously(from: videoConnection, completionHandler: { (sampleBuffer, error) -> Void in
guard let buffer = sampleBuffer else { return }
let imageData = AVCaptureStillImageOutput.jpegStillImageNSDataRepresentation(buffer)
let dataProvider = CGDataProvider(data: imageData! as CFData)
let cgImageRef = CGImage(jpegDataProviderSource: dataProvider!, decode: nil, shouldInterpolate: true, intent: .defaultIntent)
let image = UIImage(cgImage: cgImageRef!, scale: 1, orientation: .right)
completion(image)
})
}
Here is how I click the image within the ViewController:
#IBAction func clickImage(_ sender: AnyObject) {
cameraView.clickPicture { (image) in
//use "image" variable
}
}
Later, I attempt to upload this picture to the user's iCloud account using CloudKit. However I receive an error saying the record is too large. I then came across this SO post, which says to use a CKAsset. However, the only constructor for a CKAsset requires a URL.
Is there a generic way I can get a URL from any UIImage? Otherwise, how can get a URL from the image I clicked using my custom camera (I have seen other posts about getting a url from a UIImagePickerController)? Thanks!
CKAsset represents some external file (image, video, binary data and etc). This is why it requires URL as init parameter.
In your case I would recommend to use following steps to upload large image to CloudKit:
Save UIImage to local storage (e.g. documents directory).
Initialize CKAsset with path to image in local storage.
Upload asset to Cloud.
Delete image from local storage when uploading completed.
Here is some code:
// Save image.
let path = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true).first!
let filePath = "\(path)/MyImageName.jpg"
UIImageJPEGRepresentation(image, 1)!.writeToFile(filePath, atomically: true)
let asset = CKAsset(fileURL: NSURL(fileURLWithPath: filePath)!)
// Upload asset here.
// Delete image.
do {
try FileManager.default.removeItem(atPath: filePath)
} catch {
print(error)
}

iOS 9 save gif to photo library

Now that AssetsLibrary has been deprecated, we're supposed to use the photos framework, specifically PHPhotoLibrary to save images and videos to a users camera roll.
Using ReactiveCocoa, such a request would look like:
func saveImageAsAsset(url: NSURL) -> SignalProducer<String, NSError> {
return SignalProducer { observer, disposable in
var imageIdentifier: String?
PHPhotoLibrary.sharedPhotoLibrary().performChanges({
let changeRequest = PHAssetChangeRequest.creationRequestForAssetFromImageAtFileURL(url)
let placeholder = changeRequest?.placeholderForCreatedAsset
imageIdentifier = placeholder?.localIdentifier
}, completionHandler: { success, error in
if let identifier = imageIdentifier where success {
observer.sendNext(identifier)
} else if let error = error {
observer.sendFailed(error)
return
}
observer.sendCompleted()
})
}
}
I created a gif from a video using Regift and I can verify that the gif exists inside my temporary directory. However when I go save that gif to the camera roll, I get a mysterious error: NSCocoaErrorDomain -1 (null), which is really super helpful.
Has anyone ever experienced this issue?
You can try this.
let data = try? Data(contentsOf: /*Your-File-URL-Path*/)
PHPhotoLibrary.shared().performChanges({
PHAssetCreationRequest.forAsset().addResource(with: .photo, data: data!, options: nil)
})

Save GIF image from URL to Camera Roll

I'm trying to save a GIF from URL to Camera Roll with the following code:
var image = UIImage(data: NSData(contentsOfURL: self.imageView.sd_imageURL())!)
UIImageWriteToSavedPhotosAlbum(image, nil, nil, nil)
but after saving, the GIF become a still image, anyone can help me?
Thanks!
You can save GIF via PHPhotoLibrary
PHPhotoLibrary.shared().performChanges({
let request = PHAssetCreationRequest.forAsset()
request.addResource(with: .photo, fileURL: YOUR_GIF_URL, options: nil)
}) { (success, error) in
if let error = error {
completion(.failure(error))
} else {
completion(.success(true))
}
}
Try this:
import AssetsLibrary
let image = NSData(contentsOfURL: url)
ALAssetsLibrary().writeImageDataToSavedPhotosAlbum(image, metadata: nil, completionBlock: { (assetURL: NSURL!, error: NSError!) -> Void in
print(assetURL)
})

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