ISO/IEC 21145:2023

INTERNATIONAL ISO/IEC
STANDARD 21145
First edition
2023-09
Information technology — Computer
graphics, image processing and
environmental data representation
— Style representation for mixed and
augmented reality
Reference number
© ISO/IEC 2023
© ISO/IEC 2023
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© ISO/IEC 2023 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms, definitions and abbreviated terms . 1
3.1 Terms and definitions . 1
3.2 Abbreviated terms . 2
4 Principles and requirements .2
5 MAR content model: Target for stylization . 2
6 MAR stylization as MAR behavior components . 3
6.1 MARSNode. 3
6.2 Behavior::MARSNode . 4
6.3 BehaviorStyleVisual . 5
7 Example usage . 6
8 Conformance . 7
Bibliography . 8
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© ISO/IEC 2023 – All rights reserved

Foreword
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Commission) form the specialized system for worldwide standardization. National bodies that are
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accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives or
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ISO and IEC draw attention to the possibility that the implementation of this document may involve the
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This document was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology,
Subcommittee SC 24, Computer graphics, image processing and environmental data representation.
Any feedback or questions on this document should be directed to the user’s national standards
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© ISO/IEC 2023 – All rights reserved

Introduction
Mixed and augmented reality (MAR) refers to a spatially coordinated combination of media/information
components that represent, on the one hand the real world and its objects and on the other hand those
that are virtual, synthetic and computer generated. MAR as an information medium strives to provide
rich experience based on realism, presence and augmentation [ISO/IEC 18039].
This document describes a set of information constructs for stylizing the MAR content and its objects.
ISO/IEC 3721 specifies the MAR scene with the core objects and their attributes [ISO/IEC 3721] This
[2]
document further refines ISO/IEC 3721 similarly to how CSS (Cascading Style Sheets) augments
[1]
HTML-5 (Hyper Text Markup Language) for web document stylization. Among the various core
MAR content objects defined in ISO/IEC 3721, virtual objects that augment real world objects may
be subject to further stylization. Stylization refers to the act of making certain information follow a
particular form for various purposes. As MAR contents become more widespread and sophisticated,
there is an increasing need for its stylization and its separation from the core content for its efficient
specification. The augmentation style can affect the whole MAR experience in terms of its naturalness
(how harmonious objects appear in relation to the real world into which they are inserted), and
conspicuousness and saliency (how augmentations stand out for visibility and readability). This in
turn can be important for efficient information transfer through the MAR content. Style specification
components are thus associated with and applied to the virtual objects used for augmenting the real
world objects in the MAR content (see Figure 1).

The real world objects are associated or augmented with the virtual scene/objects shown within the left box. The
style objects represent the constructs for further specifying their “styles” for presentation to the users.
Figure 1 — The general structure of mixed and augmented reality (MAR) content
[ISO/IEC 18039]
This work only establishes the information model, and neither promotes nor mandates the use of a
specific language, file format, algorithm, device, or implementation method. It is to be considered
as a minimum basic model and a sound basis that can be extended for other purposes in actual
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© ISO/IEC 2023 – All rights reserved

implementations (e.g. application standards, specific file formats). It is designed for ease, generality,
and extendibility and is illustrated in this document with various examples and implementation results.
This document is based on ISO/IEC 18039 which specifies a reference architecture for the MAR system
as a contents-browser/player. In ISO/IEC 18039, the MAR content is specified as the input to the MAR
system that describes the scene and objects’ behavior. The MAR system parses, simulates and renders
the content to the display (See Figure 2).

The MAR Scene or equivalent content description is an input to the larger MAR system which will interpret it and
render it to a display for user consumption [ISO/IEC 18039].
Figure 2 — The generic MAR system architecture
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© ISO/IEC 2023 – All rights reserved

INTERNATIONAL STANDARD ISO/IEC 21145:2023(E)
Information technology — Computer graphics, image
processing and environmental data representation — Style
representation for mixed and augmented reality
1 Scope
This document specifies:
1) Constructs for representing and specifying various augmentation and presentation styles. While
augmentations can be in modalities other than the visual (e.g. aural, haptic), this work addresses
the visual augmentation style only.
2) A model for how to associate the stylization constructs to the augmentation objects. Specifically,
the MAR behavior object in ISO/IEC 3721 is extended for this purpose.
3) Other miscellaneous functionalities and abstractions that support the stylization of augmentation
objects.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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.
ISO/IEC 18039, Information technology — Computer graphics, image processing and environmental data
representation — Mixed and augmented reality (MAR) reference model
ISO/IEC 3721, Information technology — Computer graphics, image processing and environmental data
representation —Information model for mixed and augmented reality content — Core Objects and their
Attributes
3 Terms, definitions and abbreviated terms
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO/IEC 18039, ISO/IEC 3721, and
the following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1.1
stylization
act of enforcing certain information presentation to follow a particular form or behave in a given way
for various purposes such as to highlight it, emphasize it, or make it more readable and perceptible
© ISO/IEC 2023 – All rights reserved

3.2 Abbreviated terms
AR augmented reality
AV augmented virtuality
CSS cascading style sheet
HTML hypertext markup language
MAR mixed and augmented reality
MAR-RM mixed and augmented reality reference model
MR mixed reality
UI user interface
VR virtual reality
4 Principles and requirements
The MAR content model should provide reasonable generality, being able to express various genres
of mixed reality contents, especially AR and AV under a consistent and unified representational
framework. Other requirements are as follows:
— independent of particular sensor/device model, algorithm or implementation platform,
— be able to handle virtually any digital information and media, both static and dynamic, as
augmentation such as text, images, videos, animation, HTML document elements, etc.,
— provide useful abstract and declarative constructs for often used content functionalities and
minimize manual scripting or programming,
— make use of existing standard constructs, where possible,
— flexible/extendible to accommodate new future requirements.
To fulfil these requirements, this document will continue to adopt the component based approach,
as defined in ISO/IEC 3721. Components are collections of objects that perform or represent similar
operations, displays, or functions. The component framework is ideal for introducing and modelling
new capabilities. New objects/styles can be added or expanded as needed. The components form a
structured environment that ensures consistent behavior, usability and generality.
5 MAR content model: Target for stylization
To properly set the context for this work and aid understandability of this document, we first briefly
ou
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