How can I properly use CGImageProperties.h on iOS 4+

For my university project I need to obtain various information about a photo on the iOS platform to determine if the room the user is in contains the correct lighting conditions. Data I need includes ISO, exposure, brightness.

I noticed these data values are found in this manner: CGImageProperties.h -> kCGImagePropertyExifDictionary -> kCGImagePropertyExifISOSpeedRatings

I do not have much formal experience in iOS development so I was wondering if anyone had further documentation for this header file or sample code, even at the most basic level, that I can digest and learn how to properly开发者_如何转开发 use CGImageProperties.h. Thank you.

Add the ImageIO framework to your app.

Then in your header file:

#import <ImageIO/CGImageProperties.h>