About Exif 3.0~ Overview of the latest revision ~December 2023
Camera and Imaging Products Association

Camera & Imaging Products Association1

History of Exif The Exif standard was established in 1995 as a standard image format for cameras that canrecord metadata*. Currently, it is used worldwide in the majority of consumer imaging devices,including not only digital cameras but also smartphones, and is known as a successful exampleof the international standards originating from Japanese industries.

（* Additional data attached to a data which are separate from the data itself. For example, For image data of adigital camera, information such as the shooting date and time and shutter speed are metadata.）

 The history of the revision, mainly related to other information tags that are highly related tothis revision, is shown below.

 Ver.1.0: 1995 (28 years ago: the 1st edition published) Ver.2.0: 1997


Added GPS Info IFD provisions that record GPS (location) information

 Ver.2.2: 2002

Classification of Exif tags (metadata)(in Annex H)
1.
2.
3.

Image structure related metadata
Shooting condition related metadata
Metadata storing other information•••

Image capture date and time, imagecapture location
Name of camera, lens, software, etc.
Name of owner, photographer, imageeditor, etc.
Description of the image itself

Added ImageUniqueID tag to prove the uniqueness of the captured image
Supported to Exif Print

Added a group of tags that can describe the camera owner, serial number, etc. to prove the history (origin) Ver.2.3: 2010•

 Ver.2.31: 2018Enabled description of time difference with UTC
Added tags related to shooting conditions such as temperature, humidity, pressure, etc. that are obtained fromsources other than image sensors

 Ver.3.0: 2023 Revision focused on "other information" other than image structure and shooting conditions

Added a scheme that enables arbitrary annotation description (AI learning data, inference results, etc.)
Added an original preservation image that records the shooting scene and keep them even to post-processing
Added guidelines for usage of information metadata for post-processing (after shooting)
Added a group of tags that can describe the name of the work person and the name of the used software in each post-processCamera & Imaging Products Association2

Background and aim of revision into Exif 3.0
 As the use of AI and IoT advances in industry, images and videos
from various cameras and image sensors are being used asimportant information in various fields. Then the importance ofcomprehensive management of various types of metadata together
with information from other sensors, etc. is increasing.
 Thus, decided to revise Exif, which is used worldwide as a common
platform for consumer imaging equipment, so that it can be used as
the basis for next-generation image metadata management.
⇒ Specifically, in addition to conventional Exif imaging information, bymaking possible to record newly (1) annotation descriptions*and (2) images and metadata that contribute to authenticity
verification integrally in an Exif image file, to improve
convenience when using images for AI.
（* "Annotation" is an annotation, and an annotation description in Exif3.0
is a description of annotation data related to Exif images in a highly
versatile text format suitable for AI utilization. ）Camera & Imaging Products Association3

Points of the revision (1)(1) Annotation description for AI utilization
 Recently while the use of image recognition using AI (image AI)
has been increasing, image AI requires annotation informationsuch as the location of objects as learning data, and also often
the case to record image AI recognition results as newannotation information.
 Traditionally usually, images and annotations were managed as
separate files and the formats differed depending on thesystem. Thus, it made operations such as copying and moving
and to manage multiple annotations for one image complicated,then could cause confusion, that was a problem.
⇒ Decided to solve the above problems by unifying the format
and integrating the image and annotation information.
Specifically, added specifications for annotation description toExif, which is used worldwide in the majority of consumer
imaging devices.
Camera & Imaging Products Association

4

Example of annotation description

ReadWrite“comment”

Annotation description

Describe a caption for the item in area 1 (rectangular frame) with "pearl" andfor the item in areas 2 and 3 with "bottle" along with the position informationof the rectangular frame* as an annotation.

* Not limited to rectangles, polygons (no restrictions on the number of vertices) and ellipses
can also be described.

⇒ Added annotation description scheme to Exif APP11
Camera & Imaging Products Association

5

Points of the revision (2)(2) Authenticity support
 Recently the problem of fake images has become an international
issue, and standards are being developed by various standardizingorganizations in the world to ensure the authenticity of informationand certify the provenance of data.
 While these standards mainly target the authenticity based on theimage completed through post-processing (editing) using asoftware after shooting, differently, from the perspective tocontribute to ensure the authenticity based on the original image
taken and recorded by a camera, revised on the following points.
 Added the definition of “Original Preservation Image,” which is ascheme that preserves the unedited image that records thescene at the time of shooting even when the image is edited,and specified in “Annex K. “ Clarified the description rule for the existing tag"ImageUniqueID". (Mandatory to be described when
adopting "original preservation image")⇒ By that, in combination with said standards relating provenancecertification, it is expected to contribute to ensure the authenticityof images from the time when they are taken and recorded.

Camera & Imaging Products Association

6

Idea of authenticity support in Exif3.0(Original preservation image and ImageUniqueID)
When taking by a camera

Case of edited by a postprocessing application
Example of changing
the background to "night"

Image
processing
duringshooting

Exifprimary
image

Actual (shooting) scene

UniqueID=ABCD EFGH

Thumbnail image

Processing out ofcamera (editingSW, etc.)

UniqueID=ABCD EFGH

Thumbnail image

Image
processing
duringshooting

originalpreservation
image

Maintained
originalpreservation
imageUniqueID=ABCD EFGH

Record an original preservation image that is the same*as the primary image（*The number of pixels may be reduced within the specified range）

Camera & Imaging Products Association

UniqueID=ABCD EFGH

Original preservation image (+ImageUniqueID)is retained without change and passed on tosubsequent stages

7

Other revisions
 Added and reviewed Exif recording information, including improving the uniqueness ofinterpretation of existing tags and clarifying operations.
 Text description has been changed from the previous ASCII format to UTF-8, which can handle
many character sets not only English.
 Tags has been added and revised.
 "Artist (main person who created the image)" tag could be written multiple names
previously, but since this would make interpretation difficult in subsequent applications, etc.,
a single name description is adopted to increase the uniqueness of interpretation.
 In addition to the existing tag "CameraOwnerName", new tags such as "Photographer"and "ImageEditor“ are added, making it possible to describe the (main) person in charge
at each stage of work.
 "ImageDescription" tag could be written including the image title previously, but a new“ImageTitle" tag is added to separate it to increase uniqueness of interpretation.

 Annex H has been newly added as guidelines regarding the subsequent use of tags.
 Categorizing each tag according to its positioning, rules has been decided for whether or not
it shall be updated (+ whether it may be deleted) when editing the image (+ metadata) in asubsequent application. This intends to prevent Exif metadata from being accidentallychanged or deleted during post-processing.

Camera & Imaging Products Association8

Reference: List of revised items
 Enabled APP11 Marker Segment to store a Box-structured data compliant with the JPEG Systemstandard Added definition of Box-structured Annotation Data
 Added Annex I and J for supplemental information of Annotation Data
 Added Tag Type of UTF-8 as Exif specific tag type
 Enabled to select UTF-8 character string in existing ASCII-type tags

 Added and changed the following tags

 Added ImageTitle Tag
 Added Photographer Information related Tags (Photographer and ImageEditor) Added Software Information related Tags (CameraFirmware, RAWDevelopingSoftware,ImageEditingSoftware, and MetadataEditingSoftware) Changed Software, Artist, and ImageUniqueID Corrected incorrect definition of GPSAltitudeRef GPSMeasureMode tag became to support positioning information obtained from GNSS in addition to GPS Added Annex H to specify Guidelines for Handling Tag Information in Post-processing by Application Software Added Annex K to specify Original Preservation Image
 Changed the description support levels of the following tags:

XResolution
YResolution
ResolutionUnit
FlashpixVersion

 Discarded Annex E.3 to specify Application Software Guidelines Corrected errors, typos and omissions accumulated up to this edition
 Restructured and revised the entire document structure and style
Camera & Imaging Products Association

9