Hello, I'm trying to extract specific creator data from the IPTC of an image, but not having a lot of luck.. I'm talking about the objects for the following keys: kCGImagePropertyIPTCContactInfoAddress kCGImagePropertyIPTCContactInfoCity kCGImagePropertyIPTCProvinceState kCGImagePropertyIPTCContactInfoPostalCode etc. (basically the Creator Contact info from the IPTC) This is my code: Code: CGImageSourceRef source = CGImageSourceCreateWithURL((CFURLRef) url, NULL); NSDictionary *metadata = (NSDictionary *)CGImageSourceCopyPropertiesAtIndex(source, 0, NULL); [[metadata objectForKey:(id)kCGImagePropertyIPTCDictionary] objectForKey:(id)kCGImagePropertyIPTCContactInfoAddress] etc.. Unfortunately, this doesn't seem to work. When compiling, I get this error message: Code: "_kCGImagePropertyIPTCContactInfoAddress", referenced from: -[AppController getMetadata:] in AppController.o ld: symbol(s) not found collect2: ld returned 1 exit status All other EXIF and IPTC data is fine.. Any help? Thanks in advance!