References http://developer.apple.com/library/ios/documentation/Miscellaneous/Conceptual/iPhoneOSTechOverview/iPhoneOSTechOverview.pdf.
{"Image DocumentName": "Referenceshttp://developer.apple.com/library/ios/documentation/Miscellaneous/Conceptual/iPhoneOSTechOverview/iPhoneOSTechOverview.pdf.", "Image ImageDescription": "https://developer.apple.com/library/mac/documentation/cocoa/conceptual/objectivec/objc.pdf.", "Image XResolution": "37", "Image YResolution": "37", "Image ResolutionUnit": "Pixels/Centimeter", "Image Software": "SlidePlayer", "Image YCbCrPositioning": "Centered"}