MPEG-7 is a multimedia content description standard. It was standardized in ISO/IEC 15938 (Multimedia content description interface).[1][2][3][4] This description will be associated with the content itself, to allow fast and efficient searching for material that is of interest to the user. MPEG-7 is formally called Multimedia Content Description Interface. Thus, it is not a standard which deals with the actual encoding of moving pictures and audio, like MPEG-1, MPEG-2 and MPEG-4. It uses XML to store metadata, and can be attached to timecode in order to tag particular events, or synchronise lyrics to a song, for example.

It was designed to standardize:

The combination of MPEG-4 and MPEG-7 has been sometimes referred to as MPEG-47.[5]


MPEG-7 is intended to provide complementary functionality to the previous MPEG standards, representing information about the content, not the content itself ("the bits about the bits"). This functionality is the standardization of multimedia content descriptions. MPEG-7 can be used independently of the other MPEG standards - the description might even be attached to an analog movie. The representation that is defined within MPEG-4, i.e. the representation of audio-visual data in terms of objects, is however very well suited to what will be built on the MPEG-7 standard. This representation is basic to the process of categorization. In addition, MPEG-7 descriptions could be used to improve the functionality of previous MPEG standards. With these tools, we can build an MPEG-7 Description and deploy it. According to the requirements document,1 "a Description consists of a Description Scheme (structure) and the set of Descriptor Values (instantiations) that describe the Data." A Descriptor Value is "an instantiation of a Descriptor for a given data set (or subset thereof)." The Descriptor is the syntactic and semantic definition of the content. Extraction algorithms are inside the scope of the standard because their standardization is not required to allow interoperability.


The MPEG-7 (ISO/IEC 15938) consists of different Parts. Each part covers a certain aspect of the whole specification.

MPEG-7 Parts[4][6]
Part Number First public release date (First edition) Latest public release date (edition) Latest amendment Title Description
Part 1 ISO/IEC 15938-1 2002 2002 2006 Systems the architectural framework of MPEG-7, the carriage of MPEG-7 content - TeM (Textual format for MPEG-7) and the binary format for MPEG-7 descriptions (BiM)[7]
Part 2 ISO/IEC 15938-2 2002 2002 Description definition language
Part 3 ISO/IEC 15938-3 2002 2002 2010 Visual
Part 4 ISO/IEC 15938-4 2002 2002 2006 Audio
Part 5 ISO/IEC 15938-5 2003 2003 2015 Multimedia description schemes
Part 6 ISO/IEC 15938-6 2003 2003 2011 Reference software
Part 7 ISO/IEC 15938-7 2003 2003 2011 Conformance testing
Part 8 ISO/IEC TR 15938-8 2002 2002 2011 Extraction and use of MPEG-7 descriptions
Part 9 ISO/IEC 15938-9 2005 2005 2012 Profiles and levels
Part 10 ISO/IEC 15938-10 2005 2005 Schema definition
Part 11 ISO/IEC TR 15938-11 2005 2005 2012 MPEG-7 profile schemas
Part 12 ISO/IEC 15938-12 2008 2012 Query format
Part 13 ISO/IEC 15938-13 2015 2015 Compact descriptors for visual search

Relation between description and content

Independence between description and content
Independence between description and content

An MPEG-7 architecture requirement is that description must be separate from the audiovisual content.

On the other hand, there must be a relation between the content and description. Thus the description is multiplexed with the content itself.

On the right side you can see this relation between description and content.

MPEG-7 tools

Relation between different tools and elaboration process of MPEG-7
Relation between different tools and elaboration process of MPEG-7

MPEG-7 uses the following tools:

On the right side you can see the relation between MPEG-7 tools.

MPEG-7 applications

There are many applications and application domains which will benefit from the MPEG-7 standard. A few application examples are:

Software and demonstrators for MPEG-7

See also


The MPEG-7 standard was originally written in XML Schema (XSD), which constitutes semi-structured data. For example, the running time of a movie annotated using MPEG-7 in XML is machine-readable data, so software agents will know that the number expressing the running time is a positive integer, but such data is not machine-interpretable (cannot be understood by agents), because it does not convey semantics (meaning), known as the "Semantic Gap." To address this issue, there were many attempts to map the MPEG-7 XML Schema to the Web Ontology Language (OWL), which is a structured data equivalent of the terms of the MPEG-7 standard (MPEG-7Ontos, COMM, SWIntO, etc.). However, these mappings did not really bridge the "Semantic Gap," because low-level video features alone are inadequate for representing video semantics.[10] In other words, annotating an automatically extracted video feature, such as color distribution, does not provide the meaning of the actual visual content.[11]



  1. ^ ISO. "ISO/IEC 15938-1:2002 - Information technology -- Multimedia content description interface -- Part 1: Systems". Retrieved 2009-10-31.
  2. ^ MPEG. "About MPEG - Achievements". Archived from the original on July 8, 2008. Retrieved 2009-10-31.
  3. ^ MPEG. "Terms of Reference". Archived from the original on February 21, 2010. Retrieved 2009-10-31.
  4. ^ a b MPEG. "MPEG standards - Full list of standards developed or under development". Archived from the original on April 20, 2010. Retrieved 2009-10-31.
  5. ^ NetworkDictionary. "Complete Protocol dictionary, glossary and reference - M". Archived from the original on 2010-01-01. Retrieved 2009-12-26.
  6. ^ ISO/IEC JTC 1/SC 29 (2009-10-30). "MPEG-7 (Multimedia content description interface)". Archived from the original on 2013-12-31. Retrieved 2009-11-10.
  7. ^ ISO/IEC JTC1/SC29/WG11 (October 2004). "MPEG-7 Overview (version 10)". Retrieved 2009-11-01.
  8. ^ "MPEG-7 Ontology". Retrieved 29 June 2017.
  9. ^ Lux, Mathias. "Caliph & Emir: MPEG-7 photo annotation and retrieval." Proceedings of the 17th ACM international conference on Multimedia. ACM, 2009.
  10. ^ Sikos, Leslie F.; Powers, David M.W. (2015). "Knowledge-Driven Video Information Retrieval with LOD". Proceedings of the Eighth Workshop on Exploiting Semantic Annotations in Information Retrieval. pp. 35–37. doi:10.1145/2810133.2810141. ISBN 9781450337908. S2CID 16544890.
  11. ^ Boll, Susanne; Klas, Wolfgang; Sheth, Amit (1998). "Overview on Using Metadata to Manage Multimedia Data". Using Metadata to Integrate and Apply Digital Media. McGraw-Hill. p. 3. ISBN 978-0070577350.