GB/T 24355-2023 Geographic information - Portrayal
1 Scope
This document specifies a conceptual schema for describing symbols, portrayal functions that map geospatial features to symbols, and the collection of symbols and portrayal functions into portrayal catalogues. This conceptual schema can be used in the design of portrayal systems. It allows feature data to be separate from portrayal data, permitting data to be portrayed in a dataset independent manner.
This International Standard is not applicable to the following:
——standard symbol collection (e.g. International Chart 1 - IHO);
——a standard for symbol graphics (e.g. scalable vector graphics [SVG]);
——portrayal services (e.g. web map service);
——capability for non-visual portrayal (e.g. aural symbology);
——dynamic rendering (e.g. on the fly contouring of tides);
——portrayal finishing rules (e.g. generalization, resolve overprinting, displacement rules);
——3D symbolization (e.g. simulation modeling).
2 Conformance
Any portrayal catalogue, portrayal function and symbol describing the portrayal of geographic information claiming conformance with this International Standard shall pass the relevant tests of the abstract test suite presented in Annex A, and those portrayal extension requirements that are applicable to the extension or extensions being used.
Conformance classes are defined for the portrayal core, and the core plus extensions. These extensions provide additional functionality, and are not mutually exclusive of each other.
Core portrayal conformance classes
——Conformance class - portrayal core (general)
——Conformance class - portrayal core - symbol
——Conformance class - portrayal core - portrayal function
——Conformance class - portrayal core - portrayal catalogue
Portrayal function extension conformance classes
——Conformance class - portrayal core plus conditional function extension
——Conformance class - portrayal core plus context extension
——Conformance class - portrayal core plus function symbol parameter extension
Symbol extension conformance classes
——Conformance class - portrayal core plus compound symbol extension
——Conformance class - portrayal core plus complex symbol extension
——Conformance class - portrayal core plus reusable symbol component extension
——Conformance class - portrayal core plus symbol parameter extension
3 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 23707-2009 Geographic information - Spatial schema (ISO 19107:2003, IDT)
GB/T 28585-2012 Geographic information - Methodology for feature cataloguing (ISO 19110:2005, IDT)
GB/T 30170-2013 Geographic information - Spatial referencing by coordinates (ISO 19111:2007, IDT)
ISO/TS 19103:2005 Geographic information - Conceptual schema language
Note: GB/T 35647-2017, Geographic information - Conceptual schema language (ISO 19103:2015, IDT)
ISO 19109:2005 Geographic information - Rules for application schema
ISO 19115:2003 Geographic information - Metadata
Note: GB/T 19710-2005, Geographic information - Metadata (ISO 19115:2003, MOD)
ISO/TS 19139:2007 Geographic information - Metadata - XML schema implementation
ISO/IEC 19501:2005 Information technology - Open Distributed Processing - Unified modeling language (UML) Version 1.4.2
4 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
4.1
annotation
any marking on illustrative material for the purpose of clarification
Note: Numbers, letters, symbols (4.31), and signs are examples of annotation.
4.2
class
description of a set of objects that share the same attributes, operations, methods, relationships and semantics
Note: A class may use a set of interfaces to specify collections of operations it provides to its environment.
[SOURCE: ISO/TS 19103:2005, 4.27]
4.3
complex symbol
symbol (4.31) composed of other symbols of different types
Example: A dashed line symbol with a point (4.19) symbol repeated at an interval.
4.4
compound symbol
symbol (4.31) composed of other symbols of the same type
Example: A point (4.19) symbol that is composed of two point graphics.
4.5
conditional feature portrayal function
function (4.11) that maps a geographic feature (4.8) to a symbol (4.31) based on some condition evaluated against a property or attribute of a feature
4.6
curve
1-dimensional geometric primitive (4.13), representing the continuous image of a line
[SOURCE: GB/T 23707-2009, 4.23, modified]
4.7
dataset
identifiable collection of data
Note: A dataset may be a smaller grouping of data which, though limited by some constraint such as spatial extent or feature (4.8) type, is located physically within a larger dataset. Theoretically, a dataset may be as small as a single feature or feature attribute (4.9) contained within a larger dataset. A hardcopy map or chart may be considered a dataset.
[SOURCE: ISO 19115:2003, 4.2]
4.8
feature
abstraction of real world phenomena
Note: A feature may occur as a type or an instance (4.14). Feature type or feature instance shall be used when only one is meant.
[SOURCE: ISO 19101:2002, 4.11]
4.9
feature attribute
characteristic of a feature (4.8)
Example 1: A feature attribute named “colour” may have an attribute value “green” which belongs to the data type “text”.
Example 2: A feature attribute named “length” may have an attribute value “82.4” which belongs to the data type “real”.
Note 1: A feature attribute has a name, a data type, and a value domain associated to it. A feature attribute for a feature instance (4.14) also has an attribute value taken from the value domain.
Note 2: In a feature catalogue, a feature attribute may include a value domain but does not specify attribute values for feature instances.
[SOURCE: ISO 19101:2002, 4.12]
4.10
feature portrayal function
function (4.11) that maps a geographic feature (4.8) to a symbol (4.31)
4.11
function
rule that associates each element from a domain (source, or domain of the function) to a unique element in another domain (target, co-domain, or range)
[SOURCE: GB/T 23707-2009, 4.41, modified]
4.12
geographic information
information concerning phenomena implicitly or explicitly associated with a location relative to the Earth
[SOURCE: ISO 19101:2002, 4.16]
4.13
geometric primitive
geometric object representing a single, connected, homogeneous element of space
[SOURCE: GB/T 23707-2009, 4.48, modified]
4.14
instance
object that realizes a class (4.2)
[SOURCE: GB/T 23707-2009, 4.53]
4.15
layer
basic unit of geographic information (4.12) that may be requested as a map from a server
[SOURCE: ISO 19128:2005, 4.6]
GB/T 24355-2023 Geographic information - Portrayal
1 Scope
This document specifies a conceptual schema for describing symbols, portrayal functions that map geospatial features to symbols, and the collection of symbols and portrayal functions into portrayal catalogues. This conceptual schema can be used in the design of portrayal systems. It allows feature data to be separate from portrayal data, permitting data to be portrayed in a dataset independent manner.
This International Standard is not applicable to the following:
——standard symbol collection (e.g. International Chart 1 - IHO);
——a standard for symbol graphics (e.g. scalable vector graphics [SVG]);
——portrayal services (e.g. web map service);
——capability for non-visual portrayal (e.g. aural symbology);
——dynamic rendering (e.g. on the fly contouring of tides);
——portrayal finishing rules (e.g. generalization, resolve overprinting, displacement rules);
——3D symbolization (e.g. simulation modeling).
2 Conformance
Any portrayal catalogue, portrayal function and symbol describing the portrayal of geographic information claiming conformance with this International Standard shall pass the relevant tests of the abstract test suite presented in Annex A, and those portrayal extension requirements that are applicable to the extension or extensions being used.
Conformance classes are defined for the portrayal core, and the core plus extensions. These extensions provide additional functionality, and are not mutually exclusive of each other.
Core portrayal conformance classes
——Conformance class - portrayal core (general)
——Conformance class - portrayal core - symbol
——Conformance class - portrayal core - portrayal function
——Conformance class - portrayal core - portrayal catalogue
Portrayal function extension conformance classes
——Conformance class - portrayal core plus conditional function extension
——Conformance class - portrayal core plus context extension
——Conformance class - portrayal core plus function symbol parameter extension
Symbol extension conformance classes
——Conformance class - portrayal core plus compound symbol extension
——Conformance class - portrayal core plus complex symbol extension
——Conformance class - portrayal core plus reusable symbol component extension
——Conformance class - portrayal core plus symbol parameter extension
3 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 23707-2009 Geographic information - Spatial schema (ISO 19107:2003, IDT)
GB/T 28585-2012 Geographic information - Methodology for feature cataloguing (ISO 19110:2005, IDT)
GB/T 30170-2013 Geographic information - Spatial referencing by coordinates (ISO 19111:2007, IDT)
ISO/TS 19103:2005 Geographic information - Conceptual schema language
Note: GB/T 35647-2017, Geographic information - Conceptual schema language (ISO 19103:2015, IDT)
ISO 19109:2005 Geographic information - Rules for application schema
ISO 19115:2003 Geographic information - Metadata
Note: GB/T 19710-2005, Geographic information - Metadata (ISO 19115:2003, MOD)
ISO/TS 19139:2007 Geographic information - Metadata - XML schema implementation
ISO/IEC 19501:2005 Information technology - Open Distributed Processing - Unified modeling language (UML) Version 1.4.2
4 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
4.1
annotation
any marking on illustrative material for the purpose of clarification
Note: Numbers, letters, symbols (4.31), and signs are examples of annotation.
4.2
class
description of a set of objects that share the same attributes, operations, methods, relationships and semantics
Note: A class may use a set of interfaces to specify collections of operations it provides to its environment.
[SOURCE: ISO/TS 19103:2005, 4.27]
4.3
complex symbol
symbol (4.31) composed of other symbols of different types
Example: A dashed line symbol with a point (4.19) symbol repeated at an interval.
4.4
compound symbol
symbol (4.31) composed of other symbols of the same type
Example: A point (4.19) symbol that is composed of two point graphics.
4.5
conditional feature portrayal function
function (4.11) that maps a geographic feature (4.8) to a symbol (4.31) based on some condition evaluated against a property or attribute of a feature
4.6
curve
1-dimensional geometric primitive (4.13), representing the continuous image of a line
[SOURCE: GB/T 23707-2009, 4.23, modified]
4.7
dataset
identifiable collection of data
Note: A dataset may be a smaller grouping of data which, though limited by some constraint such as spatial extent or feature (4.8) type, is located physically within a larger dataset. Theoretically, a dataset may be as small as a single feature or feature attribute (4.9) contained within a larger dataset. A hardcopy map or chart may be considered a dataset.
[SOURCE: ISO 19115:2003, 4.2]
4.8
feature
abstraction of real world phenomena
Note: A feature may occur as a type or an instance (4.14). Feature type or feature instance shall be used when only one is meant.
[SOURCE: ISO 19101:2002, 4.11]
4.9
feature attribute
characteristic of a feature (4.8)
Example 1: A feature attribute named “colour” may have an attribute value “green” which belongs to the data type “text”.
Example 2: A feature attribute named “length” may have an attribute value “82.4” which belongs to the data type “real”.
Note 1: A feature attribute has a name, a data type, and a value domain associated to it. A feature attribute for a feature instance (4.14) also has an attribute value taken from the value domain.
Note 2: In a feature catalogue, a feature attribute may include a value domain but does not specify attribute values for feature instances.
[SOURCE: ISO 19101:2002, 4.12]
4.10
feature portrayal function
function (4.11) that maps a geographic feature (4.8) to a symbol (4.31)
4.11
function
rule that associates each element from a domain (source, or domain of the function) to a unique element in another domain (target, co-domain, or range)
[SOURCE: GB/T 23707-2009, 4.41, modified]
4.12
geographic information
information concerning phenomena implicitly or explicitly associated with a location relative to the Earth
[SOURCE: ISO 19101:2002, 4.16]
4.13
geometric primitive
geometric object representing a single, connected, homogeneous element of space
[SOURCE: GB/T 23707-2009, 4.48, modified]
4.14
instance
object that realizes a class (4.2)
[SOURCE: GB/T 23707-2009, 4.53]
4.15
layer
basic unit of geographic information (4.12) that may be requested as a map from a server
[SOURCE: ISO 19128:2005, 4.6]
