IPTC Photo Metadata
IPTC Photo Metadata is a metadata standard, primarily used with photographic images. It was developed by IPTC, the International Press Telecommunications Council. It defines metadata elements, which can be serialized as either XMP or IIM (Information Interchange Model).
The standard was developed around 2007-2008. It was essentially a combination of the older IIM and IPTC Core Schema for XMP standards, and the new IPTC Extension Schema standard.
The metadata items remain partitioned into two separate schema specifications, which have their own version numbers. Items compatible with IIM are defined in the IPTC Core Schema Specification, and other items are defined in the IPTC Extension Schema Specification.
- IPTC Guidelines & Support - Search for "Reference Images"