使用Swift(iOS)和Photos框架保存自定义图像的元数据

我正在尝试通过使用Photos框架将合成生成的元数据添加到相机卷中.我得到了保存和编辑工作,但我似乎可以弄清楚如何添加元数据.我尝试了很多方法,比如通过创建CoreGraphics图像来添加元数据(参见下面的代码).所有这些方法都没有给我一个错误,但是当我在Mac上打开图像时,我无法看到元数据.

任何人都能指出我在正确的方向吗？

PHPhotoLibrary.sharedPhotoLibrary().performChanges({
let assets : PHFetchResult = PHAsset.fetchAssetsWithLocalIdentifiers([self.localIdentifier],options: nil);
let asset : PHAsset = assets[0] as! PHAsset;
let changerequest = PHAssetChangerequest(forAsset: asset);
changerequest.LOCATIOn = self.currentLOCATIOn;

asset.requestContentEdiTingInputWithOptions(nil,completionHandler: { (input: PHContentEdiTingInput?,info: [NSObject : AnyObject]) -> Void in


    guard let input = input else { return }

    let imageManager : PHImageManager = PHImageManager();
    let requestoptions : PHImagerequestOptions = PHImagerequestOptions();
    requestoptions.resizeMode = PHImagerequestOptionsResizeMode.None;

    imageManager.requestImageForAsset(asset,targetSize: PHImageManagerMaximumSize,contentMode: PHImageContentMode.Default,options: PHImagerequestOptions(),resultHandler: { (let image : UIImage?,_) -> Void in

        let output : PHContentEdiTingOutput = PHContentEdiTingOutput(contentEdiTingInput: input);

        PHPhotoLibrary.sharedPhotoLibrary().performChanges({ () -> Void in

            let changerequest = PHAssetChangerequest(forAsset: asset);

            /* Neu */
            let imageData : NSData = NSData(contentsOfURL: (input.fullSizeImageURL)!)!;
            let image : CIImage = CIImage(data: imageData)!;
            let dataPtr = CFDataCreate(kcfAllocatorDefault,UnsafePointer<UInt8>(imageData.bytes),imageData.length)


            // Save off the properties
            let imagesource : CGImagesourceRef = CGImagesourceCreateWithData(dataPtr,nil)!;
            var Metadata : NSMutableDictionary = NSMutableDictionary(Dictionary: CGImagesourceCopyProperties(imagesource,nil)!);



/* Add some values to Metadata */
....

            NSLog("New Metadata: %@",Metadata);

            // Save the image
            let outputImagesource : CGImagesourceRef = CGImagesourceCreateWithData(dataPtr,nil)!;
            let jpegData : CFMutableDataRef = CFDataCreateMutable(kcfAllocatorDefault,0);
            let outputDesTination : CGImageDesTinationRef = CGImageDesTinationCreateWithData(jpegData,CGImagesourceGetType(outputImagesourcE)!,1,nil)!;

            // add the image data to the desTination
            CGImageDesTinationAddImageFromsource(outputDesTination,outputImagesource,Metadata);

            if CGImageDesTinationFinalize(outputDesTination)
            {
                NSLog("successful image creation.");
                // process the image rendering,adjustment data creation and finalize the asset edit.
            }
            else
            {
                NSLog("Image creation Failed.");
            }



            (jpegData as NSData).writeToURL(output.renderedContentURL,atomically: truE);


            let options : @R_197_10495@ng = NS@R_197_10495@ng(format: "%f|%f|%f|%f|%f|%f",self.saturationSlider.value,self.warmthSlider.value,self.brightnessSlider.value,self.sharpnessSlider.value,self.contrastSlider.value,self.gAMMaSlider.value ) as @R_197_10495@ng;
            let nsObject: AnyObject? = NSBundle.mainBundle().infoDictionary!["CFBundleShortVersion@R_197_10495@ng"];

            output.adjustmentData = PHAdjustmentData(formatIdentifier: NSBundle.mainBundle().bundlEIDentifier!,formatVersion: nsObject as! @R_197_10495@ng,data: options.dataUsingEncoding(NSUTF8@R_197_10495@ngEncoding)!);

            changerequest.contentEdiTingOutput = output;

            },completionHandler: { (_bool,_error) -> Void in
                if !_bool && error != nil
                {
                    NSLog("%@",error!);
                }
        });
    });
});
},_error) -> Void in
});

PHPhotoLibrary.shared().performChanges({

    let creationrequest = PHAssetChangerequest.creationrequestForAsset(from: self.anImage!)

    let aLOCATIOn = CLLOCATIOn(latitude: 27.63866,longitude: -80.39707)

    creationrequest.LOCATIOn = aLOCATIOn

    creationrequest.isFavorite = true

    creationrequest.creationDate = Date()

},completionHandler: {success,error in
    if !success {
        print("error creaTing asset: \(error!)")
    } else {
        print("success creaTing asset!")
    }
})