Glossary
Key terms from JPEG Trust Part 1, second edition (ISO/DIS 21617-1). We explain them in plain language, so these are not the official definitions. The number beside each term is its clause in the draft standard.
- Actor 3.1
A person, device or piece of software that takes part in creating, changing or sharing media. Examples are a camera, an image editor, a cloud service or the person using them.
- Anonymisation 3.2
Changing data in a media asset to protect an actor's privacy by hiding features that could identify them.
- Assertion 3.3
A statement that an actor makes about a media asset. Assertions are stored in a trust manifest.
- Authentic media asset 3.4
A media asset that can be checked, can be relied on, or both.
- Author 3.5
The person whose creativity led to a work being made or changed.
- Claim 3.6
A digitally signed, tamper-evident structure in a trust manifest. It points to the assertions made about a media asset, holds the information needed for the content binding, and states if any assertion was redacted.
- Claim signature 3.7
The digital signature on a claim, made with an actor's private key. It is part of the trust manifest.
- Composed media asset 3.8
A media asset made by combining several media assets.
- Content binding 3.9
Information that ties the content of a media asset to a specific trust record. It is either a hard binding or a soft binding.
- Coordinate system 3.10
A way to describe points in a space of a given number of dimensions by using coordinates.
- Fingerprint 3.11
A set of properties calculated from a media asset's content that identifies that content or close copies of it.
- Generative AI media asset (synthetic media asset) 3.12
A media asset made using artificial intelligence and machine learning.
- Hard binding 3.13
One or more cryptographic hashes that uniquely identify a whole media asset or part of it.
- Intellectual property rights (IPR) 3.14
The exclusive rights an actor holds over intellectual work they created.
- Invisible watermark 3.15
Information added to a media asset's content in a way that people can hardly perceive. It can, for example, uniquely identify the asset or store a reference to its trust record.
- JPEG 1 3.16
A widely used image compression format, specified in ISO/IEC 10918-1.
- JUMBF (JPEG Universal Metadata Box Format) 3.17
A universal format for embedding any type of metadata in box-based JPEG file formats, specified in ISO/IEC 19566-5.
- Manipulated media asset (manipulated media) 3.18
A media asset changed with the intention of misleading people.
- Media asset 3.19
A digital asset such as an image, video, audio or text.
- Media asset content 3.20
The part of a media asset that holds the actual content, such as an image's pixel data, plus any technical metadata needed to understand or display it, such as a colour profile or encoding parameters.
- Media asset integrity 3.21
The state of a media asset that has not been corrupted.
- Media asset metadata 3.22
The part of a media asset that holds non-technical information about it or its content, such as location, creator, annotations or rights information.
- Media asset original 3.23
A media asset produced by a device or method with no modifications.
- Media asset provenance 3.24
Information about a media asset, including the trail of changes starting from an actor, such as its origin. A change missing from the trail is treated in the same way as an invalid or unverifiable provenance chain.
- Media asset source 3.25
The non-human actor that created the media asset original.
- Modified media asset 3.26
A media asset that has been changed.
- Natural media asset 3.27
A media asset acquired by a sensor.
- Obfuscation 3.28
Changing data in a media asset to protect it against unauthorised access.
- Provenance 3.29
The history of a media asset and how it has interacted with actors and other media assets, as shown by its provenance data.
- Provenance data 3.30
The set of trust records for a media asset and, for a composed media asset, its ingredients.
- Region of interest (ROI) 3.31
Part of a media asset's content picked out for a particular purpose, such as the face in a portrait, a foreground object or a scene in a video.
- Registrar 3.32
An actor that carries out a registration.
- Registration 3.33
Storing information about a media asset, such as the asset itself, its metadata or its provenance, separately from the asset.
- Signer 3.34
An actor who digitally signs a media asset.
- Signing 3.35
The process that links an actor to a media asset in a tamper-evident way.
- Soft binding 3.36
A content identifier that is either not statistically unique, such as a fingerprint, or embedded in the content as an invisible watermark.
- Trust declaration 3.37
A special type of trust manifest that, when present, always comes first in the trust record. It represents the actor that created the media asset and holds only the mandatory assertions.
- Trust indicators 3.38
Information derived from a media asset and its trust record that shows how trustworthy the asset is in a given context.
- Trust indicator set 3.39
A set of trust indicators derived from a media asset and its trust record.
- Trust manifest 3.40
A set of information about the provenance of a media asset. A trust manifest is part of a trust record.
- Trust profile 3.41
A set of expressions used to evaluate each trust indicator in a trust indicator set, to show how trustworthy a media asset is.
- Trust record 3.42
One or more trust manifests, either embedded in a media asset or stored outside it.
- Trust report 3.43
The result of evaluating a trust indicator set against a trust profile.
- Trustworthy 3.44
Able to be relied on as being what it claims to be.
- Verifiable 3.45
Able to be checked.
- Visible watermark 3.46
A perceptible part of a media asset's content that gives people information about its provenance.