SIST-TS ISO/TS 22028-3:2011

TECHNICAL ISO/TS
SPECIFICATION 22028-3
First edition
2006-08-15
Photography and graphic technology —
Extended colour encodings for digital
image storage, manipulation and
interchange —
Part 3:
Reference input medium metric RGB
colour image encoding (RIMM RGB)
Photographie et technologie graphique — Codages par couleurs
étendues pour stockage, manipulation et échange d'image
numérique —
Partie 3: Codage d'image en couleurs RVB par référence d'entrée par
voie métrique
Reference number
©
ISO 2006
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ii © ISO 2006 – All rights reserved

Contents Page
Foreword. iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions. 1
4 Requirements . 5
4.1 General. 5
4.2 Reference viewing environment. 6
4.3 Reference medium primaries and white point. 7
4.4 RIMM RGB colour image encoding. 7
4.5 Inverse RIMM RGB transformation . 11
Annex A (informative) Example colour rendering transform from RIMM RGB to ROMM RGB. 14
Bibliography . 18

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
In other circumstances, particularly when there is an urgent market requirement for such documents, a
technical committee may decide to publish other types of normative document:
⎯ an ISO Publicly Available Specification (ISO/PAS) represents an agreement between technical experts in
an ISO working group and is accepted for publication if it is approved by more than 50 % of the members
of the parent committee casting a vote;
⎯ an ISO Technical Specification (ISO/TS) represents an agreement between the members of a technical
committee and is accepted for publication if it is approved by 2/3 of the members of the committee casting
a vote.
An ISO/PAS or ISO/TS is reviewed after three years in order to decide whether it will be confirmed for a
further three years, revised to become an International Standard, or withdrawn. If the ISO/PAS or ISO/TS is
confirmed, it is reviewed again after a further three years, at which time it must either be transformed into an
International Standard or be withdrawn.
ISO/TS 22028-3 was prepared by Technical Committee ISO/TC 42, Photography, in collaboration with
Technical Committee ISO/TC 130, Graphic technology.
ISO 22028 consists of the following parts, under the general title Photography and graphic technology —
Extended colour encodings for digital image storage, manipulation and interchange:
⎯ Part 1: Architecture and requirements
⎯ Part 2: Reference output medium metric RGB colour image encoding (ROMM RGB)
[Technical Specification]
⎯ Part 3: Reference input medium metric RGB colour image encoding (RIMM RGB)
[Technical Specification]
iv © ISO 2006 – All rights reserved

Introduction
This part of ISO 22028 has been developed in order to meet the industry need for a complete,
fully-documented, publicly-available definition of a wide-primary scene-referred extended colour gamut
red-green-blue (RGB) colour image encoding. This encoding provides a way to represent scene-referred
images that does not limit the colour gamut to those colours capable of being displayed on a CRT monitor, or
require the use of negative RGB colorimetry co-ordinates.
A scene-referred extended colour gamut colour encoding is particularly desirable for professional photography
applications. For example, colours captured by digital cameras, as well as conventional capture devices such
as photographic film, can be outside those that can be represented within the colour gamut of a typical
monitor or other types of output devices. Similarly, scene-referred images can have a larger luminance
dynamic range than output-referred images since they have not been modified by a colour rendering process
to fit the images to a specific output medium applying appropriate tone and colour reproduction aims.
Retaining the unrendered scene-referred image data has the advantage that it preserves the option to make
decisions about how a particular image is to be rendered. For example, a scene-referred image of a backlit
scene can retain information about both the dark foreground region and the bright background region of the
scene. This information can be used to make a properly exposed print of either the foreground region or the
background region, or alternatively can be used to create an improved image by rendering the two regions
differently.
By using a standard scene-referred extended colour gamut colour image encoding, images can be stored,
interchanged and manipulated without restricting the image to a particular rendering intent or output device.
The Reference input medium metric RGB (RIMM RGB) colour encoding specified in this part of ISO 22028
meets the needs of these types of applications. An extended dynamic range version of this colour image
encoding known as Extended reference input medium metric RGB (ERIMM RGB) is also specified for use with
high-dynamic range input sources. (E)RIMM RGB is intended to be a companion to the output-referred ROMM
RGB colour image encoding specified in ISO/TS 22028-2. Both colour encodings are based on the same
“wide RGB” additive colour space to facilitate the development of image processing algorithms and simple
colour rendering transformations to convert scene-referred RIMM RGB images to rendered output-referred
ROMM RGB images.
The International Organization for Standardization (ISO) draws attention to the fact that it is claimed that
compliance with this document may involve the use of patents concerning extended range colour encodings
given in 4.4 and 4.5. ISO takes no position concerning the evidence, validity and scope of this patent right.
The holder of this patent right has assured the ISO that he/she is willing to negotiate licences under
reasonable and non-discriminatory terms and conditions with applicants throughout the world. In this respect,
the statement of the holder of this patent right is registered with ISO. Information may be obtained from
Director, Corporate Commercial Affairs
Eastman Kodak Company
343 State Street
Rochester, New York 14650-0211, U.S.A.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights other than those identified above. ISO shall not be held responsible for identifying any or all such patent
rights.
TECHNICAL SPECIFICATION ISO/TS 22028-3:2006(E)

Photography and graphic technology — Extended colour
encodings for digital image storage, manipulation and
interchange —
Part 3:
Reference input medium metric RGB colour image encoding
(RIMM RGB)
1 Scope
This part of ISO 22028 specifies a family of scene-referred extended colour gamut RGB colour image
encodings designated as Reference input medium metric RGB (RIMM RGB). Digital images encoded using
RIMM RGB can be manipulated, stored, transmitted, displayed, or printed by digital still picture imaging
systems. Three precision levels are defined using 8-, 12- and 16-bits/channel. An extended luminance
dynamic range version of RIMM RGB is also defined designated as Extended reference input medium metric
RGB (ERIMM RGB). Two precision levels of ERIMM RGB are defined using 12- and 16-bits/channel.
2 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.
ISO 22028-1:2004, Photography and graphic technology — Extended colour encodings for digital image
storage, manipulation and interchange — Part 1:Architecture and requirements
ISO/CIE 10527:1991, CIE standard colorimetric observers
CIE Publication 15, Colorimetery
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
adapted white
colour stimulus that an observer who is adapted to the viewing environment would judge to be perfectly
achromatic and to have a luminance factor of unity; i.e. absolute colorimetric coordinates that an observer
would consider to be a perfect white diffuser
NOTE The adapted white can vary within a scene.
3.2
additive RGB colour space
colorimetric colour space having three colour primaries (generally red, green and blue) such that CIE XYZ
tristimulus values can be determined from the RGB colour space values by forming a weighted combination of
the CIE XYZ tristimulus values for the individual colour primaries, where the weights are proportional to the
radiometrically linear colour space values for the corresponding colour primaries
NOTE 1 A simple linear 3 × 3 matrix transformation can be used to transform between CIE XYZ tristimulus values and
the radiometrically linear colour space values for an additive RGB colour space.
NOTE 2 Additive RGB colour spaces are defined by specifying the CIE chromaticity values for a set of additive RGB
primaries and a colour space white point, together with a colour component transfer function.
3.3
colorimetric colour space
colour space having an exact and simple relationship to CIE colorimetric values
NOTE Colorimetric colour spaces include those defined by CIE (e.g. CIE XYZ, CIELAB, CIELUV, etc.), as well as
colour spaces that are simple transformations of those colour spaces (e.g. additive RGB colour spaces).
3.4
colour component transfer function
single variable, monotonic mathematical function applied individually to one or more colour channels of a
colour space
NOTE 1 Colour component transfer functions are frequently used to account for the nonlinear response of a reference
device and/or to improve the visual uniformity of a colour space.
NOTE 2 Generally, colour component transfer functions will be nonlinear functions such as a power-law (i.e. “gamma”)
function or a logarithmic function. However, in some cases a linear colour component transfer function can be used.
3.5
colour encoding
generic term for a quantized digital encoding of a colour space, encompassing both colour space encodings
and colour image encodings
3.6
colour gamut
solid in a colour space, consisting of all those colours that are either: present in a specific scene, artwork,
photograph, photomechanical, or other reproduction; or capable of being created using a particular output
device and/or medium
3.7
colour image encoding
digital encoding of the colour values for a digit
...