Reading/Writing image XMP on iPhone / Objective-c

Question

I'm trying to read XMP information from a jpeg on iPhone.

I can get tags from IPTC, TIFF or EXIF easily using ImageIO but not XMP. I'm specially interested the rating tag.

Does anyone know how to do that?

Answer 1

I've been trying to figure this out myself for a bit. Based on what I've found it looks like a you will need to create or find a custom toolset for parsing the XMP data. It is stored in an XML format. Adobe has an SDK and toolset for dealing with XMP data that can be found here. If you look into that there was an error in the compilation instructions for the SDK in XCode. You can get a correction here on there forums.

You can also find the adobe XMP specification documents here

I still haven't gotten very deep into the rabbit hole of this topic yet myself but since no one else was responding here I thought I'd give you what little I've been able to dig up on the topic.