IPTC-IIM

IPTC is a metadata format used in some types of image files.

Format
Structurally, IPTC is a sequence of data blocks, which the specification calls "DataSets". Each DataSet contains a 1-byte "record number" and a 1-byte "DataSet number", which together indicate the type of data stored in that DataSet.

Take note of DataSet {1, 90} (Coded Character Set), which indicates the character encoding used in other DataSets.

Multi-byte integers use big-endian byte order.

Embedding
In a TIFF file, IPTC uses tag 33723.

IPTC may be embedded in Photoshop Image Resources metadata, with Resource ID 0x0404.

JPEG files often contain IPTC embedded in Photoshop Image Resources.

Specifications

 * IPTC version 4.1