ISO/TS 23564:2020

Image technology colour management - Evaluating colour transform accuracy in ICC profiles

This document describes procedures for evaluating the accuracy of colorimetric rendering intents in ICC profiles. It applies to v4 ICC profiles made according to ISO 15076-1. It does not apply to subjective tests of ICC profiles, such as for perceptual or saturation rendering intents, and it does not apply to high dynamic range colour media or spaces.

Titre manque

Barvno upravljanje upodobitvenih tehnologij - Vrednotenje natančnosti barvne pretvorbe v ICC-profilih

General Information

• Status: Published
• Publication Date: 26-Jan-2020
• ICS: 37.100.01 - Graphic technology in general
• Technical Committee: ISO/TC 130 - Graphic technology
• Drafting Committee: ISO/TC 130/JWG 7 - Joint TC 130 - ICC WG: colour management
• Current Stage: 9092 - International Standard to be revised
• Start Date: 07-Nov-2023
• Completion Date: 13-Dec-2025
• Ref Project: SIST-TS ISO/TS 23564:2020 - Image technology colour management - Evaluating colour transform accuracy in ICC profiles

Overview

ISO/TS 23564:2020 specifies procedures for evaluating the colourimetric accuracy of ICC v4 profiles (as defined in ISO 15076-1). The technical specification focuses on objective tests for colour transform accuracy of colorimetric rendering intents (media-relative / ICC-Absolute), describing how to quantify forward and inverse model performance in ICC profiles. It does not cover subjective tests (perceptual or saturation rendering intents) or high dynamic range (HDR) colour media/spaces.

Key topics and requirements

• Profile evaluation tests: Two main test classes:
  • Round trip tests - verify inversion accuracy when converting PCS → device encoding → PCS using BToA1Tag and AToB1Tag.
  • Device model tests - assess forward/inverse model accuracy for predicting device colourimetry from encoding values (and vice versa).
• Tags and models:
  • Forward model encoded in AToB1Tag; inverse in BToA1Tag.
  • Use chromaticAdaptationTag to convert between measurement illuminants and PCS (D50) when required.
• Test data and metrics:
  • Use test images (e.g., ISO 12642-2) and additional application-specific colour subsets (neutrals, skin tones).
  • Report colour differences as median, maximum and 95th percentile ΔE00, with PCSLAB scaled to ICC‑Absolute colourimetry.
  • Typical round-trip results: median ΔE00 < 1, maximum ΔE00 < 2 (guidance only).
• Evaluation principles:
  • Forward model accuracy should be validated against independent measurements where possible; report whether test colours were used as training data.
  • Round-trip error is an inversion accuracy metric and does not directly predict forward-model fidelity.
  • Combine forward (AToB1) and round-trip uncertainties to estimate inverse-model error (RMS of mean errors).
• Practical cautions (Annex A): beware overfitting to training data and printer reproducibility - sometimes a stiffer model yields better long-term performance.

Applications and who uses it

ISO/TS 23564:2020 is practical for:

• Colour management engineers and ICC profile developers
• Colour quality assurance (QA) labs in print and imaging
• Device manufacturers (presses, proofers, scanners)
• Software vendors (Colour Management Modules / CMMs)
• Prepress and digital proofing workflows that require objective colour-metric validation

Use cases include profile validation, QA acceptance criteria, CMM comparison studies, and contract specifications for accurate colour reproduction.

Related standards

• ISO 15076-1 - ICC profile format (v4)
• ISO 12642-2 - test images / input data for 4‑colour printing characterization

Keywords: ISO/TS 23564:2020, ICC profiles, colour transform accuracy, colour management, AToB1Tag, BToA1Tag, ΔE00, PCSLAB, chromaticAdaptationTag.

Standards Content (Sample)

TECHNICAL ISO/TS
SPECIFICATION 23564
First edition
2020-01
Image technology colour
management — Evaluating colour
transform accuracy in ICC profiles
Reference number
©
ISO 2020
© ISO 2020
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Fax: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms, definitions and abbreviated terms . 1
3.1 Terms and definitions . 1
3.2 Abbreviated terms . 2
4 Profile evaluation tests . 2
4.1 General . 2
4.2 Round trip tests . 2
4.3 Device model tests . 3
5 Round trip accuracy . 3
5.1 General . 3
5.2 Test image . 3
5.3 Round trip test . 3
6 Accuracy of forward/inverse model . 4
Annex A (informative) Applicability of the forward model metric . 5
Bibliography . 6
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.
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 ISO documents 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).
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. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
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.
This document was prepared by Technical Committee ISO/TC 130, Graphic technology.
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.
iv © ISO 2020 – All rights reserved

Introduction
International Color Consortium (ICC) input and output profiles contain transforms between device
data encodings and the ICC Profile Connection Space (PCS). These transforms should provide either an
accurate colour match or a pleasing rendering, depending on the chosen rendering intent.
The following guidelines are provided to assist in the evaluation of the colorimetric rendering intent
transforms in ICC v4 profiles. Any tolerances provided in this document are for guidance only and may
not be suitable for all applications.
TECHNICAL SPECIFICATION ISO/TS 23564:2020(E)
Image technology colour management — Evaluating colour
transform accuracy in ICC profiles
1 Scope
This document describes procedures for evaluating the accuracy of colorimetric rendering intents in
ICC profiles.
It applies to v4 ICC profiles made according to ISO 15076-1.
It does not apply to subjective tests of ICC profiles, such as for perceptual or saturation rendering
intents, and it does not apply to high dynamic range colour media or spaces.
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 15076-1, Image technology colour management — Architecture, profile format and data structure —
Part 1: Based on ICC.1:2010
3 Terms, definitions and abbreviated terms
3.1 Terms and definitions
For the purpose of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1.1
AToB1Tag
structure in an ICC profile that encodes the forward model in media-relative colorimetry
3.1.2
BToA1Tag
structure in an ICC profile that encodes the inverse model in media-relative colorimetry
3.1.3
chromaticAdaptationTag
invertible matrix which converts a CIE XYZ colour, measured using the actual illumination conditions
and relative to the actual adopted white, to a CIE XYZ colour relative to the PCS adopted white with
complete adaptation
3.1.4
colour lookup table
array of values corresponding to the ou
...

SLOVENSKI STANDARD
01-april-2020
Barvno upravljanje upodobitvenih tehnologij - Vrednotenje natančnosti
barvne pretvorbe v ICC-profilih
Image technology colour management - Evaluating colour transform accuracy in ICC
profiles
Ta slovenski standard je istoveten z: ISO/TS 23564:2020
ICS:
17.180.20 Barve in merjenje svetlobe Colours and measurement of
light
37.100.01 Grafična tehnologija na Graphic technology in
splošno general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

TECHNICAL ISO/TS
SPECIFICATION 23564
First edition
2020-01
Image technology colour
management — Evaluating colour
transform accuracy in ICC profiles
Reference number
©
ISO 2020
© ISO 2020
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Fax: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms, definitions and abbreviated terms . 1
3.1 Terms and definitions . 1
3.2 Abbreviated terms . 2
4 Profile evaluation tests . 2
4.1 General . 2
4.2 Round trip tests . 2
4.3 Device model tests . 3
5 Round trip accuracy . 3
5.1 General . 3
5.2 Test image . 3
5.3 Round trip test . 3
6 Accuracy of forward/inverse model . 4
Annex A (informative) Applicability of the forward model metric . 5
Bibliography . 6
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.
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 ISO documents 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).
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. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
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.
This document was prepared by Technical Committee ISO/TC 130, Graphic technology.
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.
iv © ISO 2020 – All rights reserved

Introduction
International Color Consortium (ICC) input and output profiles contain transforms between device
data encodings and the ICC Profile Connection Space (PCS). These transforms should provide either an
accurate colour match or a pleasing rendering, depending on the chosen rendering intent.
The following guidelines are provided to assist in the evaluation of the colorimetric rendering intent
transforms in ICC v4 profiles. Any tolerances provided in this document are for guidance only and may
not be suitable for all applications.
TECHNICAL SPECIFICATION ISO/TS 23564:2020(E)
Image technology colour management — Evaluating colour
transform accuracy in ICC profiles
1 Scope
This document describes procedures for evaluating the accuracy of colorimetric rendering intents in
ICC profiles.
It applies to v4 ICC profiles made according to ISO 15076-1.
It does not apply to subjective tests of ICC profiles, such as for perceptual or saturation rendering
intents, and it does not apply to high dynamic range colour media or spaces.
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 15076-1, Image technology colour management — Architecture, profile format and data structure —
Part 1: Based on ICC.1:2010
3 Terms, definitions and abbreviated terms
3.1 Terms and definitions
For the purpose of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1.1
AToB1Tag
structure in
...