ISO/IEC 23008-12:2025
(Main)Information technology — High efficiency coding and media delivery in heterogeneous environments — Part 12: Image File Format
Information technology — High efficiency coding and media delivery in heterogeneous environments — Part 12: Image File Format
This document specifies the Image File Format, an interoperable storage format for a single image, a collection of images, and sequences of images. The format defined in this document is built on tools defined in ISO/IEC 14496-12 and enables the interchange, editing, and display of images, as well as the carriage of metadata associated with those images. The Image File Format defines structures used to contain metadata, how to link that metadata to the images, and defines how metadata of certain forms is carried. This document also specifies brands for the storage of images and image sequences conforming to High Efficiency Video Coding (HEVC), Advanced Video Coding (AVC), JPEG, Versatile Video Coding (VVC) and Essential Video Coding (EVC). NOTE The storage of HEVC, AVC, VVC and EVC video sequences is out of scope and is provided in ISO/IEC 14496-15.
Technologies de l'information — Codage à haute efficacité et livraison des medias dans des environnements hétérogènes — Partie 12: Format de fichier d'image
General Information
Relations
Standards Content (Sample)
International
Standard
ISO/IEC 23008-12
Third edition
Information technology — High
2025-07
efficiency coding and media
delivery in heterogeneous
environments —
Part 12:
Image File Format
Technologies de l'information — Codage à haute efficacité et
livraison des medias dans des environnements hétérogènes —
Partie 12: Format de fichier d'image
Reference number
© ISO/IEC 2025
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© ISO/IEC 2025 – All rights reserved
ii
Contents Page
Foreword .vi
Introduction .vii
1 Scope . 1
2 Normative references . 1
3 Terms, definitions, abbreviated terms and symbols . 2
3.1 Terms and definitions .2
3.2 Abbreviated terms .6
3.3 Mathematical functions .7
4 Overview . 7
5 General requirements . 7
5.1 General requirements on files .7
5.2 General requirements on readers.7
5.3 Multi-purpose files .8
5.4 Other boxes .8
6 Single image and image collection . 8
6.1 General .8
6.2 Derivation from the ISO base media file format .8
6.3 Derivation of an output image of an image item .8
6.4 Roles of images .9
6.4.1 General .9
6.4.2 Hidden images .9
6.4.3 Cover image . .9
6.4.4 Thumbnail images .9
6.4.5 Auxiliary images .10
6.4.6 Master images .10
6.4.7 Pre-derived coded images .10
6.4.8 Multi-layer images .10
6.4.9 Predictively coded image items .11
6.5 Image properties .11
6.5.1 General .11
6.5.2 Decoder configuration and initialization . 12
6.5.3 Image spatial extents . 12
6.5.4 Pixel aspect ratio . 13
6.5.5 Colour information . 13
6.5.6 Pixel information .14
6.5.7 Relative location . 15
6.5.8 Image properties for auxiliary images . 15
6.5.9 Clean aperture .16
6.5.10 Image rotation .16
6.5.11 Layer selection .17
6.5.12 Image mirroring .18
6.5.13 Image scaling .18
6.5.14 Content light level .19
6.5.15 Mastering display colour volume . 20
6.5.16 Content colour volume . 20
6.5.17 Required reference types .21
6.5.18 Creation time information .21
6.5.19 Modification time information . 22
6.5.20 User description . 22
6.5.21 Accessibility text . 23
6.5.22 Auto exposure information . .24
6.5.23 White balance information .24
6.5.24 Focus information . 25
© ISO/IEC 2025 – All rights reserved
iii
6.5.25 Flash exposure information . 26
6.5.26 Depth of field information . 26
6.5.27 Panorama information .27
6.5.28 Sub-sample information . 28
6.5.29 Target output layer set . 28
6.5.30 Wipe transition effect . 29
6.5.31 Zoom transition effect . 30
6.5.32 Fade transition effect .31
6.5.33 Split transition effect .32
6.5.34 Suggested transition period . 33
6.5.35 Suggested time display duration . 33
6.5.36 Ambient viewing environment . 34
6.5.37 Progressive derived image item information . 35
6.5.38 Single stream .37
6.5.39 Camera extrinsic matrix . 38
6.5.40 Camera intrinsic matrix .41
6.6 Derived images and derived image items.42
6.6.1 General .42
6.6.2 Derived image types and derived image item types .43
6.7 Image metadata .45
6.8 Entity and sample groups .45
6.8.1 Relating an untimed item to a timed sequence .45
6.8.2 Burst images . 46
6.8.3 'tsyn' entity group .47
6.8.4 'iaug' entity group .47
6.8.5 'ster' entity group . 48
6.8.6 Bracketed sets/logically group of images at capture-time . 48
6.8.7 User-defined image collections .51
6.8.8 Panorama .52
6.8.9 Slideshow entity group . 53
6.8.10 Progressive rendering entity group . 53
6.9 Auxiliary image item types and sample formats . 54
6.9.1 CICP-compliant alpha plane . 54
6.9.2 CICP-compliant depth map . 55
6.10 Text and font items. 55
6.10.1 Text item . 55
6.10.2 Text properties . 56
6.10.3 Font item . 58
6.10.4 Font properties .59
7 Image sequences .60
7.1 General . 60
7.2 Derivation from the ISO base media file format . 60
7.2.1 Track Header box . 60
7.2.2 Handler type . 60
7.2.3 Coding Constraints box .61
7.3 Presentation of an image sequence track .61
7.4 Sample groups .62
7.4.1 Direct reference samples list .62
7.5 Other tracks . 63
7.5.1 General . 63
7.5.2 Thumbnail image sequence track . 63
7.5.3 Auxiliary image sequence track. 64
8 Metadata support .64
8.1 General . 64
8.2 Metadata for image items . 65
8.2.1 General . 65
8.2.2 Deductive information . 65
8.3 Metadata for image sequence tracks . 65
© ISO/IEC 2025 – All rights reserved
iv
8.4 Integrity checks . 66
8.4.1 General . 66
8.4.2 Syntax . . 66
8.4.3 Semantics . 66
9 Extensions to the ISO base media file format. 67
10 Image file format brands . 67
10.1 General .67
10.2 Image and image collection brands .67
10.2.1 General requirements on brands .67
10.2.2 'mif1' structural brand . 68
10.2.3 'mif2' structural brand . 69
10.2.4 'pred' brand .70
10.2.5 '1pic' brand .71
10.3 Image sequence brands.71
10.3.1 'msf1' structural brand .71
11 Region and region annotation .72
11.1 Overview . 72
11.2 Common definitions for image sequence or video tracks and for image items . 72
11.2.1 Region geometry structure . 72
11.2.2 Mask item .76
11.3 Regions and region annotations for an image item . 77
11.3.1 General . 77
11.3.2 Region item. 78
11.3.3 Derived region item . 79
11.4 Regions and region annotations for an image sequence or a video track . 79
11.4.1 General . 79
11.4.2 Region track . 80
11.4.3 Sample groups for region track . 82
Annex A (normative) Storage of externally specified metadata .85
Annex B (normative) HEVC Image File Format .87
Annex C (normative) High efficiency image file MIME type registration .98
Annex D (normative) High efficiency image sequence file MIME type registration .101
Annex E (normative) AVC in the Image File Format .103
Annex F (normative) Advanced coding image MIME type registration .107
Annex G (normative) Advanced coding sequence MIME type registration .109
Annex H (normative) JPEG in the Image File Format .111
Annex I (informative) Guidelines for specifying storage of image coding formats.115
Annex J (informative) Examples of image collections .116
Annex K (informative) Examples of progressive decoding, rendering and refinement .120
Annex L (normative) VVC Image File Format . 128
Annex M (normative) EVC Image File Format .138
Annex N (informative) Privacy and security considerations .143
Bibliography .145
© ISO/IEC 2025 – All rights reserved
v
Foreword
ISO (the International Organization for Standardization) and IEC (the International Electrotechnical
Commission) form the specialized system for worldwide standardization. National bodies that are
members of ISO or IEC participate in the development of International Standards through technical
committees established by the respective organization to deal with particular fields of technical activity.
ISO and IEC technical committees collaborate in fields of mutual interest. Other international organizations,
governmental and non-governmental, in liaison with ISO and IEC, also take part in the work.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of document should be noted. This document was drafted in accordance with the editorial rules of the ISO/
IEC Directives, Part 2 (see www.iso.org/directives or www.iec.ch/members_experts/refdocs).
ISO and IEC draw attention to the possibility that the implementation of this document may involve the
use of (a) patent(s). ISO and IEC take no position concerning the evidence, validity or applicability of any
claimed patent rights in respect thereof. As of the date of publication of this document, ISO and IEC had
received notice of (a) patent(s) which may be required to implement this document. However, implementers
are cautioned that this may not represent the latest information, which may be obtained from the patent
database available at www.iso.org/patents and https://patents.iec.ch. ISO and IEC shall not be held
responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT) see www.iso.org/iso/foreword.html.
In the IEC, see www.iec.ch/understanding-standards.
This document was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology, SC 29,
Coding of audio, picture, multimedia and hypermedia information.
This third edition cancels and replaces the second edition (ISO/IEC 23008-12:2022), which has been
technically revised.
The main changes are as follows:
— clarification on the signalling of colour information in image items;
— support for the signalling of camera intrinsic and extrinsic matrices;
— support for progressive decoding, rendering and refinement;
— support for region annotations for image sequence or video track;
— support for renderable text items.
A list of all parts in the ISO/IEC 23008 series can be found on the ISO and IEC websites.
Any feedback or questions on this document should be directed to the user’s national standards
body. A complete listing of these bodies can be found at www.iso.org/members.html and
www.iec.ch/national-committees.
© ISO/IEC 2025 – All rights reserved
vi
Introduction
The Image File Format is designed to enable the interchange of images and image sequences, as well as their
associated metadata. It forms part of a family of specifications that are box-structured, and is built using
tools defined in the ISO base media file format. This document specifies both structural brands that can be
used with any codec and brands specific to High Efficiency Video Coding (HEVC). The file format specified
in this document is referred to as the High Efficiency Image File Format (HEIF). It is suggested that HEIF be
pronounced "heaff" (like heath with an ff ending). When the requirements of the HEVC-specific brands are
applied, the file format can be referred to as the HEVC Image File Format.
This document is organized as follows:
Clause 5 specifies general requirements on files and file readers conforming to the Image File Format.
Clause 6 specifies the file structures for the storage of a single image and an image collection. Additionally,
general requirements that shall be supported in all files using the Image File Format for the storage of a
single image or an image collection are specified.
Clause 7 specifies the file structures for the storage of image sequences. Additionally, general requirements
that shall be supported in all files using the Image File Format for the storage of image sequences are
specified.
Clause 8 specifies the metadata structures for a single image, an image collection, and image sequences.
Clause 9 specifies enhancements to the ISO base media file format.
Clause 10 specifies structural brands for a single image and an image collection, as well as image sequences.
Requirements on both files and file readers are specified.
Clause 11 specifies tools to associate annotations, e.g. metadata or images with one or more regions of an
image or an image sequence.
Annex A specifies the format for storing Exif, XMP, and MPEG-7 metadata in files conforming to the Image
File Format.
Annex B specifies the format for encapsulating HEVC-coded images, image collections, and image sequences
according to the Image File Format. Annex B also specifies HEVC-specific brands for a single image and an
image collection as well as image sequences. Requirements on both files and file readers are specified.
Annex C and Annex D specify the MIME type registration for a single image or an image collection, and
image sequences, respectively, for the structural and HEVC-specific brands.
Annex E specifies the format for encapsulating AVC-coded images, image collections, and image sequences
according to the Image File Format.
Annex F and Annex G specify the MIME type registration for a single image or an image collection, and image
sequences, respectively, for the AVC-specific brands.
Annex H specifies the format for encapsulating JPEG-coded images, image collections, and image sequences
according to the Image File Format.
Annex I contains guidelines on defining new image formats and brands.
Annex J contains informative examples of single image and image collection file structures conforming to
the Image File Format.
Annex K provides examples of content encoding, file structures and player operations for progressive
rendering, progressive decoding and progressive refinement with the Image File Format.
Annex L specifies the format for encapsulating VVC-coded images, image collections, and image sequences
according to the Image File Format. Annex L also specifies VVC-specific brands for a single image and an
image collection as well as image sequences. Requirements on both files and file readers are specified.
© ISO/IEC 2025 – All rights reserved
vii
Annex M specifies the format for encapsulating EVC-coded images, image collections, and image sequences
according to the Image File Format. Annex M also specifies EVC-specific brands for a single image and an
image collection as well as image sequences. Requirements on both files and file readers are specified.
Annex N contains considerations on privacy and security relating to the use of the Image File Format.
© ISO/IEC 2025 – All rights reserved
viii
International Standard ISO/IEC 23008-12:2025(en)
Information technology — High efficiency coding and media
delivery in heterogeneous environments —
Part 12:
Image File Format
1 Scope
This document specifies the Image File Format, an interoperable storage format for a single image, a
collection of images, and sequences of images.
The format defined in this document is built on tools defined in ISO/IEC 14496-12 and enables the
interchange, editing, and display of images, as well as the carriage of metadata associated with those images.
The Image File Format defines structures used to contain metadata, how to link that metadata to the images,
and defines how metadata of certain forms is carried.
This document also specifies brands for the storage of images and image sequences conforming to High
Efficiency Video Coding (HEVC), Advanced Video Coding (AVC), JPEG, Versatile Video Coding (VVC) and
Essential Video Coding (EVC).
NOTE The storage of HEVC, AVC, VVC and EVC video sequences is out of scope and is provided in ISO/IEC 14496-15.
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 10918-1, Information technology — Digital compression and coding of continuous-tone still images:
Requirements and guidelines
ISO/IEC 14496-10, Information technology — Coding of audio-visual objects — Part 10: Advanced Video Coding
ISO/IEC 14496-12, Information technology — Coding of audio-visual objects — Part 12: ISO base media file format
ISO/IEC 14496-15, Information technology — Coding of audio-visual objects — Part 15: Carriage of network
abstraction layer (NAL) unit structured video in the ISO base media file format
ISO/IEC 23008-2, Information technology — High efficiency coding and media delivery in heterogeneous
environments — Part 2: High efficiency video coding
ISO/IEC 23090-3, Information technology — Coded representation of immersive media — Part 3: Versatile
video coding
ISO/IEC 23090-7, Information technology — Coded representation of immersive media — Part 7: Immersive
media metadata
ISO/IEC 23094-1, Information technology — General video coding — Part 1: Essential video coding
IETF RFC 3937, A Uniform Resource Name (URN) Namespace for the International Press Telecommunications
Council (IPTC)
© ISO/IEC 2025 – All rights reserved
3 Terms, definitions, abbreviated terms and symbols
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO/IEC 14496-12, ISO/IEC 14496-15
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
alternate group
group of entities (3.1.11) that are alternatives to each other and out of which only one should be selected for
processing
3.1.2
associated image item
image item (3.1.19) that is associated with the item property (3.1.29) through the ItemPropertiesBox
3.1.3
auxiliary image
image (3.1.17) that may not be intended to be displayed but provides supplemental information, such as
transparency data, complementing a respective master image (3.1.30)
3.1.4
coded image
coded representation of an image (3.1.17)
3.1.5
coded image item
item (3.1.28) whose data is a coded image (3.1.4)
3.1.6
crop-rotate-mirror derived image item
derived image item (3.1.8) of type 'iden' that is not associated with any other types of essential item
properties (3.1.12) than 'colr', 'irot', 'clap', and 'imir'
3.1.7
derived image
representation of an image (3.1.17) as an operation (3.1.34) on other images
3.1.8
derived image item
item (3.1.28) whose data is a derived image (3.1.7)
3.1.9
derived region item
item (3.1.28) whose data defines a region (3.1.43) within an image item (3.1.19), with which the item is
associated via item reference, as an operation (3.1.34) on other region items (3.1.45)
3.1.10
descriptive item property
item property (3.1.29) that describes rather than transforms the associated item
3.1.11
entity
item (3.1.28) or track
© ISO/IEC 2025 – All rights reserved
3.1.12
essential item property
item property (3.1.29) that readers are required to process
3.1.13
font item
item (3.1.28) whose data is font data
Note 1 to entry: Font items associated with text items provide font for rendering the text data.
3.1.14
HEVC image item
image item (3.1.19) of type 'hvc1' or 'lhv1'
3.1.15
hidden image
image (3.1.17) that is not intended to be displayed
3.1.16
hidden sample
sample that is not intended to be displayed
3.1.17
image
one or more arrays of pixels of different colour components described by an image item (3.1.19) or a sample
3.1.18
image collection
set of images (3.1.17) stored as items (3.1.28) of a single file according to this document
3.1.19
image item
coded image item (3.1.5) or derived image item (3.1.8)
3.1.20
Image File Format
file format specified by this document
3.1.21
image property
item property (3.1.29) for an image item (3.1.19)
3.1.22
image sequence
sequence of coded images (3.1.4) which may be associated with advisory timing and in which images may
use inter prediction (3.1.25)
3.1.23
image sequence track
track that contains an image sequence (3.1.22)
3.1.24
input image
image (3.1.17) that is used as an input for the operation (3.1.34) of the derived image item (3.1.8)
3.1.25
inter prediction
prediction derived in a manner that is dependent on data elements (e.g. sample values or motion vectors) of
images (3.1.17) other than the current image
© ISO/IEC 2025 – All rights reserved
3.1.26
intra coding
coding of an image (3.1.17) that may use intra prediction (3.1.27) and does not use in
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