Сохранение ПОЛЬЗОВАТЕЛЬСКИХ метаданных в изображении, взятом из AVFoundation в iOS

Как мне сохранить пользовательские метаданные в изображении, когда я получаю изображение с помощью инфраструктуры AVFoundation ?

Я знаю, что могу получить доступ к свойствам, независимо от того, есть ли у меня изображение как UIImage или CIImage , но свойства, которые они имеют, отличаются друг от друга (даже если это то же изображение).

Пока я обращаюсь к словарю следующим образом: (Код взят из блога Caffeinated Cocoa)

NSLog(@"about to request a capture from: %@", [self stillImageOutput]);
    [[self stillImageOutput] captureStillImageAsynchronouslyFromConnection:videoConnection completionHandler:^(CMSampleBufferRef imageSampleBuffer, NSError *error) 
    {

NSData *jpeg = [AVCaptureStillImageOutput jpegStillImageNSDataRepresentation:imageSampleBuffer] ;

        CGImageSourceRef source = CGImageSourceCreateWithData((__bridge_retained  CFDataRef)jpeg, NULL);

        //get all the metadata in the image
        NSDictionary *metadata = (__bridge NSDictionary *) CGImageSourceCopyPropertiesAtIndex(source,0,NULL);

        //make the metadata dictionary mutable so we can add properties to it
        NSMutableDictionary *metadataAsMutable = [metadata mutableCopy];

        NSMutableDictionary *EXIFDictionary = [[metadataAsMutable objectForKey:(NSString *)kCGImagePropertyExifDictionary]mutableCopy];
        NSMutableDictionary *GPSDictionary = [[metadataAsMutable objectForKey:(NSString *)kCGImagePropertyGPSDictionary]mutableCopy];
        NSMutableDictionary *RAWDictionary = [[metadataAsMutable objectForKey:(NSString *)kCGImagePropertyRawDictionary]mutableCopy];

        if(!EXIFDictionary) {
            EXIFDictionary = [NSMutableDictionary dictionary];
        }
        if(!GPSDictionary) {
            GPSDictionary = [NSMutableDictionary dictionary];
        }
        if(!RAWDictionary) {
            RAWDictionary = [NSMutableDictionary dictionary];
        }

        float _lat = gpsInfo.coordinate.latitude;
        float _lon = gpsInfo.coordinate.longitude;
        float _alt = gpsInfo.altitude;
        NSDate *_date = gpsInfo.timestamp;
        float _heading = gpsInfo.course;;

        [GPSDictionary setValue:[NSNumber numberWithFloat:_lat] 
                         forKey:(NSString*)kCGImagePropertyGPSLatitude];
        [GPSDictionary setValue:[NSNumber numberWithFloat:_lon] 
                         forKey:(NSString*)kCGImagePropertyGPSLongitude];
        [GPSDictionary setValue:[NSNumber numberWithFloat:_alt] 
                         forKey:(NSString*)kCGImagePropertyGPSAltitude];
        [GPSDictionary setValue:_date 
                         forKey:(NSString*)kCGImagePropertyGPSDateStamp];
        [GPSDictionary setValue:[NSNumber numberWithFloat:_heading] 
                         forKey:(NSString*)kCGImagePropertyGPSImgDirection];


        [EXIFDictionary setValue:@"Wasup" forKey:(NSString *)kCGImagePropertyExifUserComment];

        [RAWDictionary setValue:attitude forKey:@"Attitude"];

        //Add the modified Data back into the image’s metadata
        [metadataAsMutable setObject:EXIFDictionary forKey:(NSString *)kCGImagePropertyExifDictionary];
        [metadataAsMutable setObject:GPSDictionary forKey:(NSString *)kCGImagePropertyGPSDictionary];
        [metadataAsMutable setObject:RAWDictionary forKey:(NSString *)kCGImagePropertyRawDictionary];

        NSLog(@"Info: %@",metadataAsMutable);

        CFStringRef UTI = CGImageSourceGetType(source); //this is the type of image (e.g., public.jpeg)

        //this will be the data CGImageDestinationRef will write into
        NSMutableData *data = [NSMutableData data];

        CGImageDestinationRef destination = CGImageDestinationCreateWithData((__bridge CFMutableDataRef)data,UTI,1,NULL);

        if(!destination) {
            NSLog(@"***Could not create image destination ***");
        }

        //add the image contained in the image source to the destination, overidding the old metadata with our modified metadata

        CGImageDestinationAddImageFromSource(destination,source,0, (__bridge CFDictionaryRef) metadataAsMutable);

        //tell the destination to write the image data and metadata into our data object.
        //It will return false if something goes wrong
        BOOL success = NO;
        success = CGImageDestinationFinalize(destination);

        if(!success) {
            NSLog(@"***Could not create data from image destination ***");
        }

И я могу сохранить свое изображение следующим образом:

CIImage *testImage = [CIImage imageWithData:data];

        NSDictionary *propDict = [testImage properties];


        NSLog(@"Properties %@",propDict);

Или вот так

UIImage *imageMod = [[UIImage alloc] initWithData:data];


CGImageSourceRef source2 = CGImageSourceCreateWithData((__bridge CFDataRef)data, NULL);

        //get all the metadata in the image
NSDictionary *metadata2 = (__bridge NSDictionary *) CGImageSourceCopyPropertiesAtIndex(source2,0,NULL);

NSLog(@"WASD: %@",metadata2);

НО ни один из вариантов не возвращает мой Custom Словарь сырых данных.

Подводя итог, я хочу сохранить свой собственный объект в поле, созданном мной (в данном случае объект cmattitude)

PD: Когда я NSLOG словарь перед объединением его с image у него есть все файлы, как я хочу.

Info: {
    ColorModel = RGB;
    DPIHeight = 72;
    DPIWidth = 72;
    Depth = 8;
    Orientation = 6;
    PixelHeight = 1080;
    PixelWidth = 1920;
    "{Exif}" =     {
        ApertureValue = "2.526069";
        BrightnessValue = "4.013361";
        ColorSpace = 1;
        ComponentsConfiguration =         (
            1,
            2,
            3,
            0
        );
        ExifVersion =         (
            2,
            2,
            1
        );
        ExposureMode = 0;
        ExposureProgram = 2;
        ExposureTime = "0.03333334";
        FNumber = "2.4";
        Flash = 16;
        FlashPixVersion =         (
            1,
            0
        );
        FocalLenIn35mmFilm = 35;
        FocalLength = "4.28";
        ISOSpeedRatings =         (
            80
        );
        MeteringMode = 5;
        PixelXDimension = 1920;
        PixelYDimension = 1080;
        SceneCaptureType = 0;
        SensingMethod = 2;
        Sharpness = 0;
        ShutterSpeedValue = "4.906905";
        SubjectArea =         (
            959,
            539,
            518,
            388
        );
        UserComment = "Wazup";
        WhiteBalance = 0;
    };
    "{GPS}" =     {
        Altitude = 102;
        DateStamp = "2012-01-20 06:55:48 +0000";
        ImgDirection = "-1";
        Latitude = "35.02496";
        Longitude = "135.754";
    };
    "{Raw}" =     {
        Attitude = "Pitch: 50.913760, Roll: 36.342350, Yaw: -164.272361 @ 0.048291\n";
    };
    "{TIFF}" =     {
        Orientation = 6;
        ResolutionUnit = 2;
        XResolution = 72;
        YResolution = 72;
        "_YCbCrPositioning" = 1;
    };

Но когда я NSLOG словарь из нового образа, он дает мне это для CIIMage:

Properties {
    ColorModel = RGB;
    DPIHeight = 72;
    DPIWidth = 72;
    Depth = 8;
    Orientation = 6;
    PixelHeight = 1080;
    PixelWidth = 1920;
    "{Exif}" =     {
        ApertureValue = "2.526069";
        BrightnessValue = "4.013361";
        ColorSpace = 1;
        ComponentsConfiguration =         (
            0,
            0,
            0,
            1
        );
        ExifVersion =         (
            2,
            2,
            1
        );
        ExposureMode = 0;
        ExposureProgram = 2;
        ExposureTime = "0.03333334";
        FNumber = "2.4";
        Flash = 16;
        FlashPixVersion =         (
            1,
            0
        );
        FocalLenIn35mmFilm = 35;
        FocalLength = "4.28";
        ISOSpeedRatings =         (
            80
        );
        MeteringMode = 5;
        PixelXDimension = 1920;
        PixelYDimension = 1080;
        SceneCaptureType = 0;
        SensingMethod = 2;
        Sharpness = 0;
        ShutterSpeedValue = "4.906905";
        SubjectArea =         (
            959,
            539,
            518,
            388
        );
        UserComment = "Wazup";
        WhiteBalance = 0;
    };
    "{GPS}" =     {
        Altitude = 102;
        ImgDirection = 0;
        Latitude = "35.025";
        Longitude = "135.754";
    };
    "{JFIF}" =     {
        DensityUnit = 1;
        JFIFVersion =         (
            1,
            1
        );
        XDensity = 72;
        YDensity = 72;
    };
    "{TIFF}" =     {
        Orientation = 6;
        ResolutionUnit = 2;
        XResolution = 72;
        YResolution = 72;
        "_YCbCrPositioning" = 1;
    };

И если я NSLog UIImage , он дает мне еще меньше информации.

Спасибо!