1. Index
1. Index ...... 1 2. Purpose of the document...... 1 3. Abbreviations ...... 1 4. Related documents...... 1 5. Introduction ...... 1 6. Definitions ...... 1 6.1. Classification Scheme...... 1 6.2. Term...... 2 6.3. Term Reference ...... 2 6.4. Term Relation...... 2 6.5. TermUse ...... 2 6.6. ControlledTermUse...... 2 7. Classification Scheme Syntax and Semantics ...... 2 8. TermDefinition Syntax and Semantics ...... 3 9. ControlledTermUse datatype Syntax and Semantics...... 4 10. Example ...... 5
2. Purpose of the document
Introduce the MPEG-7 Classification Scheme to be used in the OpenDrama project.
3. Abbreviations
CS: Classification Scheme D: Descriptor DS: Descriptor Scheme MDS: Multimedia Description Schemes MPEG: Motion Picture Experts Group MPEG-7: also called “Multimedia Content Description Interface”.
4. Related documents
[mpeg7specs]: Text of 15938-5 FCD Information Technology – Multimedia Content Description Interface – Part 5 Multimedia Description Schemes [OD-MI]: MPEG7 Media information document for OpenDrama [OD-SG]: MPEG7 content structure (segments) document for OpenDrama. [OD-CI]: MPEG7 Creation Information
5. Introduction
The MPEG-7 Classification Scheme defines a scheme for classifying a subject area with a set of terms organized into a hierarchy.
6. Definitions
6.1. Classification Scheme
A set of standard terms that describes some domain. A classification scheme may organize the terms it contains with a set of term relations.
6.2. Term
A term represents one well-defined concept in the domain, covered by the classification scheme. A term in a classification scheme is referenced in a description with the TermUse datatype. A term has: • An identifier that uniquely identifies a term. • A name that may be displayed to a user o be used as a search term in a database. • A definition that describes the meaning of the term.
Terms can be put in relationship with a term relation descriptor
6.3. Term Reference
A reference to a term in a classification scheme.
6.4. Term Relation
A TermRelation represents a relation between two terms in a classification scheme such as:
• USE, the use of the related term is a synonymous of the current term. • USED FOR, the use of the current term is preferred to the use of the synonymous related term. • BROADER, the meaning of the related term is more general than the current term. • NARROWER, the meaning of the related term is more specific than the current term. • RELATED, terms are associated in some way other than those covered by one of the relations above.
When terms are organized this way, they form a classification hierarchy.
6.5. TermUse
When a term is used or referenced inside a description as a label.
6.6. ControlledTermUse
A term used in a description is controlled by requiring the term being employed to be uniquely identified.
7. Classification Scheme Syntax and Semantics
Semantics of the ClassificationSchemeType:
Name Definition ClassificationSchemeType Description scheme defining a set of terms along with their meaning and their relations. Import References a classification scheme from which to import a set of terms. All terms contained in the imported classification are added into this classification scheme. A detailed specification of importing classification schemes is given below. Term Represents one term in this classification scheme. The termId for each term must be unique within this classification scheme. uri Identifies the classification scheme with a Uniform Resource Identifier (URI). This URI must uniquely identify this classification scheme. The use of a URN as a classification scheme URI is preferred. domain Indicates a set of description elements to which this ClassificationScheme applies. The set is specified using an XPath expression. This attribute is a hint on how the ClassificationScheme can be used in a description. The XPath in this attribute is defined relative to a description, not the DDL schema. For example: a value of "//Classification/Genre" for domain indicates that the ClassificationScheme can be used for “Genre” elements inside of all “Classification” elements in the description.
8. TermDefinition Syntax and Semantics
The TermDefinition DS describes the meaning of a term. A term definition contains an identifier for a term, a set of names which are human readable, and a textual definition of the term’s meaning.
Semantics of the TermDefinitionBaseType:
Name Definition TermDefinitionBaseType Base datatype for defining a term. This datatype is used as the base for other datatypes that include term definition information. Name Indicates the human readable name for the term. It is possible to have multiple names for the same term, possibly in different languages. The language of a name is indicated by the xml:lang attribute. Preferred Indicates whether or not this is the preferred name for this term. If multiple names exist, only one label per language shall be marked preferred. Definition Defines the meaning of the term in natural language prose. It is possible to have multiple definitions in different languages for the same term. The language of a definition is indicated by the xml:lang attribute. Term Describes a term related to the containing term. Relation Indicates the type of relation existing between the contained item and the containing item. By default, it is "NT", indicating that the contained term is narrower in meaning than this term.
9. ControlledTermUse datatype Syntax and Semantics
The ControlledTermUse DS datatype is the controlled use of a term from some classification scheme. Unlike the TermUse datatype, which allows a term to be either referenced or written in free text, the ControlledTermUse controls the use of terms by requiring a reference to a term.
10. Example
A generic classification for instruments using the popular Hornbostel-Sachs-Galpin (1914) taxonomy would have the schematic representation depicted below.
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