SIST-TS ISO/TS 22028-3:2014

TECHNICAL ISO/TS
SPECIFICATION 22028-3
Second edition
2012-08-01
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 2012
© ISO 2012
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ii © ISO 2012 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Requirements . 5
4.1 General . 5
4.2 Adopted white . 7
4.3 Reference medium primaries and white point . 7
4.4 RIMM RGB, ERIMM RGB, FP-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 .19
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 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.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO/TS 22028-3 was prepared by Technical Committee ISO/TC 42, Photography.
This second edition cancels and replaces the first edition (ISO/TS 22028-3:2006), which has been
technically revised.
ISO/TS 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)
— Part 3: Reference input medium metric RGB colour image encoding (RIMM RGB) [Technical Specification]
The following parts are under preparation:
— Part 4: European Colour Initiative RGB colour image encoding [eciRGB (2008)] [Technical Specification]
iv © ISO 2012 – 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 colourimetry coordinates.
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), and a
floating point version known as FP-RIMM RGB are also specified for use with high-dynamic range input
sources. The scene-referred RIMM RGB colour image encoding is intended to be complementary 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 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, Intellectual Property Agreements and Standards
Eastman Kodak Company
343 State StreetRochester
New York 14650-0211, USA
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 22028-3:2012(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.
FP-RIMM RGB, a floating point version of RIMM RGB, defines the expression method of RIMM RGB
in a floating point figure. Three precision levels of FP-RIMM RGB are defined using 16-, 32- and
64-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 12234-2, Electronic still-picture imaging — Removable memory — Part 2: TIFF/EP image data format
ISO 22028-1:2004, Photography and graphic technology — Extended colour encodings for digital image
storage, manipulation and interchange — Part 1:Architecture and requirements
1)
ISO 11664-1, Colorimetry — Part 1: CIE standard colorimetric observers
CIE Publication 15, Colorimetery
IEEE 754, IEEE Standard for Floating-Point Arithmetic
1) Replaces ISO/CIE 10527.
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 colourimetric 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
colourimetric 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
adopted white
spectral radiance distribution as seen by an image capture or measurement device and converted to
colour signals that are considered to be perfectly achromatic and to have an observer adaptive luminance
factor of unity; i.e. colour signals that are considered to correspond to a perfect white diffuser
NOTE 1 The adopted white can vary within a scene, if such variation is supported by the imaging system.
NOTE 2 The adopted white is not required to be an estimate or approximation of the adapted white. For
example, if a scene lit by tungsten illumination is captured using a DSC with the white balance set to D55 (daylight),
the adopted white will be D55 but the adapted white will be closer to a tungsten illuminant (e.g. ISO 7589 Studio
Tungsten or CIE Illuminant A).
NOTE 3 See 3.1.
3.4
colourimetric colour space
colour space having an ex
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