IPTC Photo Metadata Standard
The IPTC Photo Metadata Standard is the most widely used standard to describe photos, because of its universal acceptance among news agencies, photographers, photo agencies, libraries, museums, and other related industries. It structures and defines metadata properties that allow users to add precise and reliable data about images.
In the early 1990s, the original “legacy” IPTC-IIM (Information Interchange Model) schema was developed to organize, systematize and unify the way information was stored and transported with images. Prior to it, every management system had its own way, which did not transfer data between other software and file formats.
Today, the IPTC Standard consists of two schemas – IPTC Core and IPTC Extension – which were built on the legacy of the original IPTC-IIM, and developed by the IPTC for professional use with a focus on news and stock photos. IPTC worked alongside Adobe on the technical implementation of the metadata that employs Adobe’s XMP technology as enriched alternative of the IIM format.
IPTC Core and IPTC Extension define metadata properties with comprehensive sets of fields that allow users to add precise and reliable data about people, locations, and products shown in an image. It also supports dates, names and identifiers regarding the creation of the photo, and a flexible way to express rights information.
What’s New in the 2014 Standard
The October 2014 version of the IPTC Photo Metadata Standard includes the addition of these fields to the Extension schema:
- Structured property Person Shown in the Image with Details. Includes fields for the name, identifiers, characteristics and a description of a person.
- Structured property Product Shown in the Image. Includes fields for the name, a GTIN identifier and a description of a product.
- Structured property CV-Term About Image. Includes fields to precisely express a term from a controlled vocabulary, including names in different languages, its identifier and more.
- Additional properties for the Artwork or Object in the Image structure. More detailed descriptions of the work, contributions to the work, circa dates of creation and style period, as well as rights data.
- Containers for machine processable Rights Expressions in different languages. One embeds the expression, another one links to an expression as a web resource.
What’s Defined by This Standard
The IPTC Photo Metadata Standard provides a structure for fields as well as descriptions for how fields should be used, and what information should be included.
The IPTC Photo Metadata Standard also specifies two technical formats for storing the information externally of image files:
- XMP: Developed by Adobe in 2002, and now maintained by ISO. It uses the Resource Description Framework (RDF) data model and XML as serialization syntax.
- IIM: It uses a genuine data model and binary structures to save the data.
How Photo Metadata formats are stored internally of image files are defined by non-IPTC file format standards, such as JPEG/JFIF, TIFF, PNG and more.