My understanding is that the caption does not get stored with the image metadata until the photo is exported (e.g. Share->SaveToFiles). Instead the caption is stored in a seperate place. I was told by Apple Developer Technical Support (DTS) that there is no API to retrieve this. However I have seen at least one App Store app that does. There’s another similar question posted at https://developer.apple.com/forums/thread/665185 .
jimblaauboer
Users receive reputation points by contributing quality content to the forums.
Posts include post and replies published on the forums.
Post authors can mark replies as Accepted to indicate successful solutions.
Apple Developer Forums admins can mark replies as Apple Recommended to indicate an approved solution
Last seen
User for