kCGImagePropertyAuxiliaryData
An array of dictionaries that contain auxiliary data for the images.
Declaration
let kCGImagePropertyAuxiliaryData: CFStringDiscussion
The value of this key is a CFArray. Each CFDictionary in the array contains auxiliary data for one of the images in the file. Use the kCGImagePropertyAuxiliaryDataType key to determine the type of data associated with the image.