Salvare i metadati CUSTOM in un'immagine presa da AVFoundation in iOS

Question

Come faccio a salvare i metadati personalizzati in un'immagine quando ottengo l'immagine usando lo AVFoundation framework?

So che posso accedere alle proprietà weather it I have my image come UIImage o CIImage ma le proprietà che questi sembrano differire l'una dall'altra (anche se è la stessa immagine).

Finora ho accedere al dizionario come questo: (codice preso da caffeina Cacao blog)

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 ***"); 
     } 

e posso sia salvare la mia immagine in questo modo:

CIImage *testImage = [CIImage imageWithData:data]; 

     NSDictionary *propDict = [testImage properties]; 


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

O come questo

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); 

BUt nessuna delle opzioni restituisce il mio dizionario personalizzato dei dati grezzi.

In sintesi quello che voglio fare è salvare il mio proprio oggetto in un campo creato da me (in questo caso un oggetto cmattitude)

PD: Quando ho NSLOG dizionario prima di fondersi con l'immagine che deve avere tutti i file come li voglio

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; 
    }; 

Ma quando NSLog il dizionario della nuova immagine che mi dà questo per il 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; 
    }; 

E se io NSLog l'UIImage mi dà ancora meno informazioni.

Grazie!

Answer 1

UIImage e CIImage non contengono tutti i metadati. In effetti, la conversione da uno di questi due formati eliminerà molti metadati, quindi IMHO, UIImage e CIImage devono essere utilizzati solo se si prevede di visualizzarli nell'interfaccia utente o di passarli a CoreImage.

È possibile leggere le proprietà immagine come questo:

- (NSDictionary *)getImageProperties:(NSData *)imageData { 
    // get the original image metadata 
    CGImageSourceRef imageSourceRef = CGImageSourceCreateWithData((__bridge CFDataRef) imageData, NULL); 
    CFDictionaryRef properties = CGImageSourceCopyPropertiesAtIndex(imageSourceRef, 0, NULL); 
    NSDictionary *props = (__bridge_transfer NSDictionary *) properties; 
    CFRelease(imageSourceRef); 

    return props; 
} 

È quindi possibile convertire il vostro NSDictionary ad un NSMutableDictionary:

NSDictionary *props = [self getImageProperties:imageData]; 
NSMutableDictionary *mutableDictionary = [NSMutableDictionary dictionaryWithDictionary:props]; 

Dopo di che, aggiungere qualsiasi campi che si desidera. Si noti che i dati EXIF ​​ viene trovato afferrando il GPS kCGImagePropertyExifDictionary, dati dal kCGImagePropertyGPSDictionary, e così via:

NSMutableDictionary *exifDictionary = properties[(__bridge NSString *) kCGImagePropertyExifDictionary]; 

guardare il file CGImageProperties intestazione per tutte le chiavi disponibili.

Bene, ora che avete fatto tutte le modifiche necessarie alle metadati, aggiungendo riprende un altro paio di passi:

// incoming image data 
NSData *imageData; 

// create the image ref 
CGDataProviderRef imgDataProvider = CGDataProviderCreateWithCFData((__bridge CFDataRef) imageData); 
CGImageRef imageRef = CGImageCreateWithJPEGDataProvider(imgDataProvider, NULL, true, kCGRenderingIntentDefault); 

// the updated properties from above 
NSMutableDictionary *mutableDictionary; 

// create the new output data 
CFMutableDataRef newImageData = CFDataCreateMutable(NULL, 0); 
// my code assumes JPEG type since the input is from the iOS device camera 
CFStringRef type = UTTypeCreatePreferredIdentifierForTag(kUTTagClassMIMEType, (__bridge CFStringRef) @"image/jpg", kUTTypeImage); 
// create the destination 
CGImageDestinationRef destination = CGImageDestinationCreateWithData(newImageData, type, 1, NULL); 
// add the image to the destination 
CGImageDestinationAddImage(destination, imageRef, (__bridge CFDictionaryRef) mutableDictionary); 
// finalize the write 
CGImageDestinationFinalize(destination); 

// memory cleanup 
CGDataProviderRelease(imgDataProvider); 
CGImageRelease(imageRef); 
CFRelease(type); 
CFRelease(destination); 

// your new image data 
NSData *newImage = (__bridge_transfer NSData *)newImageData; 

E il gioco è fatto.