IEC 61966-6:2005

Multimedia systems and equipment - Colour measurement and management - Part 6: Front projection displays

IEC 61966-6:2005 defines input test signals, measurement conditions, methods of measurement and reporting of the measured data, to be used for colour characterization and colour management of front projection displays in multimedia systems. This bilingual version (2013-03) corresponds to the monolingual English version, published in 2005-03.

Systèmes et appareils multimédia - Mesure et gestion de la couleur - Partie 6: Écrans de projection frontale

La CEI 61966-6:2005 définit les signaux d'essai d'entrée, les conditions de mesure, les méthodes de mesure et le rapport des données mesurées, destinés à être utilisés pour la caractérisation des couleurs et la gestion des couleurs des écrans de projection frontale dans les systèmes multimédia. La présente version bilingue (2013-03) correspond à la version anglaise monolingue publiée en 2005-03.

General Information

• Status: Published
• Publication Date: 16-Mar-2005
• ICS: 17.180.20 - Colours and measurement of light
• ICS: 33.160.60 - Multimedia systems and teleconferencing equipment
• Technical Committee: TC 100 - Audio, video and multimedia systems and equipment
• Current Stage: PPUB - Publication issued
• Start Date: 17-Mar-2005
• Completion Date: 30-Apr-2005

Overview

IEC 61966-6:2005 - "Multimedia systems and equipment - Colour measurement and management - Part 6: Front projection displays" defines standardized procedures for objectively characterizing the colour performance of front projection displays. The standard specifies input test signals, environmental and measurement conditions, measurement methods, and reporting formats to support colour characterization and colour management across multimedia systems. It is intended to enable consistent, equipment-specific colour control in open systems while noting that real-world viewing environments may require additional considerations.

Key Topics and Technical Requirements

• Measurement scope: Defines what to measure (spectral characteristics, intensity of primaries and white, basic colorimetric and tone characteristics, inter-channel dependency, spatial non-uniformity) and how to report results.
• Measurement conditions: Environmental and setup requirements for reproducible testing (ambient conditions, virtual screen, effective screen area and height, test patch sizes).
• Input test signals: Normalized digital/analogue input data formats and procedures for generating color patches and drive levels for measurement.
• Measurement equipment: Use of spectroradiometers and colorimeters for obtaining tristimulus values and spectral radiance; guidance on acceptable instrument characteristics.
• Methods of measurement: Procedures for capturing spectral radiance distributions of primaries, tone curves, and inter-channel dependency tests, including sampling points and interpolation methods.
• Reporting and documentation: Standardized tables and reporting forms for peak primaries and white, normalized data for tone characteristics, and spatial uniformity maps.
• Scope limits: The standard does not prescribe pass/fail limits or internal colour control algorithms and excludes detailed calibration procedures beyond measurement and reporting.

Practical Applications and Users

Who benefits from IEC 61966-6:

• Projector and front-projection display manufacturers - for product characterization and datasheets.
• Test laboratories and QA teams - for repeatable colour performance verification.
• Colour management and calibration service providers - to build profiles and correction workflows for projection systems.
• AV integrators, system specifiers, and large venue operators - to evaluate projector suitability and predict colour behaviour in installations.
• Developers of multimedia colour systems and standards bodies - as a reference for objective, comparable colour data.

Practical uses:

• Creating standardized measurement reports for product specifications.
• Feeding measured data into colour management systems for accurate colour reproduction.
• Comparing projector models on colourimetric performance such as primaries, tone response, and spatial uniformity.

Related Standards

• IEC 61966 series (Part 1, Part 2-1 sRGB, Part 3–5, Part 7–11)
• IEC 61947 (electronic projection - measurement and documentation of key performance criteria)
• IEC 60050-845, ISO/CIE 10527, CIE 15.2 (reference colorimetry and vocabulary)

Keywords: IEC 61966-6:2005, front projection displays, colour measurement, colour management, spectroradiometer, colorimeter, input test signals, tone characteristics, spatial non-uniformity.

Standards Content (Sample)

INTERNATIONAL IEC
STANDARD 61966-6
First edition
2005-03
Multimedia systems and equipment –
Colour measurement and management –
Part 6:
Front projection displays
Reference number
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INTERNATIONAL IEC
STANDARD 61966-6
First edition
2005-03
Multimedia systems and equipment –
Colour measurement and management –
Part 6:
Front projection displays
 IEC 2005  Copyright - all rights reserved
No part of this publication may be reproduced or utilized in any form or by any means, electronic or
mechanical, including photocopying and microfilm, without permission in writing from the publisher.
International Electrotechnical Commission, 3, rue de Varembé, PO Box 131, CH-1211 Geneva 20, Switzerland
Telephone: [phone] Telefax: [phone] E-mail: [e-mail] Web: www.iec.ch
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International Electrotechnical Commission
Международная Электротехническая Комиссия
For price, see current catalogue

– 2 – 61966-6  IEC(E)
CONTENTS
FOREWORD.4
INTRODUCTION.6
1 Scope .7
2 Normative references .7
3 Terms and definitions .7
4 Letters and symbols .8
5 Conditions.9
5.1 Environmental conditions .9
5.2 Conditions for measurements.9
5.3 Input digital data.11
6 Measurement equipment.11
6.1 Spectroradiometer .11
6.2 Colorimeter .12
7 Spectral characteristics and intensity of the primaries and white .12
7.1 Characteristics to be measured.12
7.2 Measurement conditions .12
7.3 Method of measurement .13
7.4 Presentation of results.13
8 Basic colorimetric characteristics .14
8.1 Characteristics to be measured.14
8.2 Method of measurement .14
8.3 Presentation of results.15
9 Tone characteristics .15
9.1 Characteristics to be measured.15
9.2 Measurement conditions .15
9.3 Method of measurement .16
9.4 Presentation of results.16
10 Other characteristics.19
10.1 Inter-channel dependency.19
10.1.1 Characteristics to be measured .19
10.1.2 Measurement conditions .20
10.1.3 Method of measurement.20
10.1.4 Presentation of results .22
10.2 Spatial non-uniformity.23
10.2.1 Characteristics to be measured .23
10.2.2 Measurement conditions .23
10.2.3 Method of measurement.23
10.2.4 Presentation of results .27

Bibliography .30

Figure 1 – Equipment arrangement for measurements (side view).10
Figure 2 – Size of colour patch.10

61966-6  IEC(E) – 3 –
Figure 3 – Example of the spectral radiance distributions r(λ), g(λ),b(λ) .13
Figure 4 – Measured points and interpolated curves .17

Figure 5 – Measurement points for spatial non-uniformity (25 points) .23
Figure 6 – Measurement points for spatial non-uniformity (9points) .25
Figure 7 – Measurement points for spatial non-uniformity (13 points) .26

Table 1 – Input data for peak primaries and peak white .13
Table 2 – Example of reporting form for colours in maximum excitations .14
Table 3 – Example of reporting form.15
Table 4 – Example set of basic normalized data for tone characteristics.18
Table 5 – Digital driving levels to generate colour patches for measurement of
interchannel dependency .20
Table 6 – Example of normalized tristimulus values (matrix A) .22
Table 7 – Example of reporting form.28
Table 8 – Example of reporting form.28
Table 9 – Example of reporting form.29

– 4 – 61966-6  IEC(E)
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
MULTIMEDIA SYSTEMS AND EQUIPMENT –
COLOUR MEASUREMENT AND MANAGEMENT –

Part 6: Front projection displays

FOREWORD
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9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 61966-6 has been prepared by technical area 2: Colour
measurement and management, of IEC technical committee 100: Audio, video and multimedia
systems and equipment.
The text of this standard is based on the following documents:
CDV Report on voting
100/835/CDV 100/915/RVC
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.

61966-6  IEC(E) – 5 –
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
IEC 61966 consists of the following parts, under the general title Multimedia systems and
equipment – Colour measurement and management:
Part 1: General
Part 2-1: Colour management – Default RGB colour space – sRGB
Part 2-2: Colour management – Extended RGB colour space – scRGB
Part 3: Equipment using cathode ray tubes
Part 4: Equipment using liquid crystal display panels
Part 5: Equipment using plasma display panels
Part 6: Front projection displays
Part 7-1: Colour printers – Reflective prints – RGB inputs
Part 7-2: Colour printers - Reflective prints - CMYK inputs (under consideration)
Part 8: Multimedia colour scanners
Part 9: Digital cameras
Part 10: Quality assessment - Colour image in network systems (under consideration)
Part 11: Quality assessment - Impaired video in network systems (under consideration)
The committee has decided that the contents of this publication will remain unchanged until
the maintenance result date indicated on the IEC web site under "http://webstore.iec.ch" in
the data related to the specific publication. At this date, the publication will be
• reconfirmed;
• withdrawn;
• replaced by a revised edition, or
• amended.
A bilingual version of this publication may be issued at a later date.

– 6 – 61966-6  IEC(E)
INTRODUCTION
The IEC 61966 series of standards defines methods and parameters for colour measurements
and colour management for use in multimedia systems and equipment, applicable to colour
production and reproduction. Part 6 deals with front projection displays.
The methods of measurement standardized in this part are designed to make possible the
objective characterization of colour reproduction of front projection displays which accept red-
green-blue analogue and/or digital signals from electrical input terminals and output light
corresponding to the intended colour. The measured results are intended to be used for the
purpose of equipment-specific colour control in order to attain colour management in open
multimedia systems and should generally be adequate for this purpose. However, in some
cases, it may be necessary to consider additional factors not addressed in this part of
IEC 61966, such as the actual environment in which the front projection display will be used,
to achieve the desired colour reproduction.
Readers of this standard are also encouraged to review IEC 61947-1 and IEC 61947-2, which
apply to the measurement and documentation of key performance criteria for multimedia
projectors.
61966-6  IEC(E) – 7 –
MULTIMEDIA SYSTEMS AND EQUIPMENT –
COLOUR MEASUREMENT AND MANAGEMENT –

Part 6: Front projection displays

1 Scope
This part of IEC 61966 defines input test signals, measurement conditions, methods of
measurement and reporting of the measured data, to be used for colour characterization and
colour management of front projection displays in multimedia systems.
Colour control within equipment is outside the scope of this part. It does not specify limiting
values for various parameters.
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.
IEC 60050-845:1987, International Electrotechnical Vocabulary (IEV) – Chapter 845:
Lighting/CIE 17.4: 1987, International Lighting Vocabulary (Joint IEC/CIE publication)
IEC 61947 (all parts), Electronic projection – Measurement and documentation of key
performance criteria
ISO/CIE 10527:1991, CIE standard colorimetric observers
CIE 15.2:1986, Colorimetry
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60050-845 and CIE
17.4, as well as the following, apply.
3.1
background
data corresponding to an image surrounding the target colour patch to be measured
3.2
colour control
effort to convert equipment-dependent colour image data to equipment-independent data for a
specific colour space including tone characteristics
3.3
colour patch, test area
square colour image on a virtual screen of the front projection display subject to be measured
for colour reproduction, in which input data for the red, green and blue channels are kept
constant within the image area

– 8 – 61966-6  IEC(E)
3.4
CRT
colorimetrically well-controlled equipment using cathode ray tubes to present colour images
with digital inputs for reference
3.5
effective screen height
vertical dimension of the effective screen area
3.6
effective screen area
area where a picture can be produced
3.7
normalized (image) signal
input signal normalized by its full-scale value, whose level is of interest in calculation and
evaluation of colour control function within front projection display (see also equation (1) in
5.3)
3.8
uncertainty (of measurement)
parameter, associated with the result of a measurement, that characterizes the dispersion of
the values that could reasonably be attributed to the particular quantity subject to
measurement (see also the IEC Guide to the expression of uncertainty in measurement,1995)
3.9
virtual screen
perfect reflecting diffuser-to-image input data
4 Letters and symbols
The notations consistently adopted in this part of IEC 61966 are summarized below.
A display area ratio
N number of bits in digital data for each channel
N
M maximum integer for non-negative N -bits system; M = 2 −1
D digital data applied for red channel
R
D digital data applied for green channel
G
D digital data applied for blue channel
B
R normalized input level to red channel
G normalized input level to green channel
B normalized input level to blue channel
X one of measured raw data using spectroradiometers and colorimeters corresponding
to tristimulus values
Y one of measured raw data using spectroradiometers and colorimeters corresponding
to tristimulus values in candela per square metre
Z one of measured raw data using spectroradiometers and colorimeters corresponding
to tristimulus values
′
R linearized data for red channel taking into account the tone characteristics of the
channel
61966-6  IEC(E) – 9 –
G′ linearized data for green channel taking into account the tone characteristics of the
channel
′
B linearized data for blue channel taking into account the tone characteristics of the
channel
′
X one of the tristimulus values normalized by Y (candela per square metre) for peak
n
white
′
Y one of the tristimulus values normalized by Y (candela per square metre) for peak
n
white
′ Y
Z one of the tristimulus values normalized by (candela per square metre) for peak
n
white
5 Conditions
5.1 Environmental conditions
All measurements specified in this document shall be carried out in a dark room. Particular
attention should be paid to prevent reflected illumination caused by the ambient objects
(desktop, wall, etc.) and direct illumination from light-emitting indicators of measuring
instruments.
An hour warm-up time should precede this measurement, if not specified by the manufacturer
of the equipment.
The mains voltage and frequency shall be at the rated value specified by the manufacturer. If
the mains voltage fluctuates, a regulated power supply shall be used to maintain the supply
voltage to within ±5 % of the rated value.
Other environmental conditions such as room temperature and relative humidity shall be
reported together with the results of measurements.
If additional environmental conditions are described in the manufacturer’s specifications,
these should be taken into account.
5.2 Conditions for measurements
Contrast, brightness and additional adjustments shall be set to the preset positions specified
by the manufacturer. If the adjustment is set to another position than the preset, the position
or corresponding value shall be reported with the results of measurements.
Geometrical adjustment shall be set to default position.
The arrangement of equipment for measurements shall be as shown in Figure 1. It incorporates
a spectroradiometer or a non-contact colorimeter, depending on the characteristics to be
measured.
The diagonal image size on the screen shall be set to the preset size specified by the
manufacturer. If no size is specified, it shall be set to 102 cm.
The height of front projection display (H) and the distance between the screen and the head
of the front projection display (L) shall be set to the preset positions specified by the
manufacturer. They depend on the screen size.

– 10 – 61966-6  IEC(E)
h
H
L
d
IEC  458/05
Key
1 Screen d Distance between screen and measuring instrument
2 Perfect reflecting diffuser
h Effective screen height
3 Front projection display
H Height projected image
4 Spectroradiometer or colorimeter
L Distance from the screen
Figure 1 – Equipment arrangement for measurements (side view
The instrument optical axis should be perpendicular to the screen. If another measurement
angle is recommended by the manufacturer, it shall be reported together with the results of
measurements. The distance d shall be 4h < d < 5,5h .
A perfect reflecting diffuser shall be set on the centre of effective screen area.
The measured light shall be that reflected by a perfect reflecting diffuser.
Test signals applied to the red, green, and blue channels shall result in a colour patch of the
size shown in Figure 2 on the screen. The positioning of the colour patch shall be referred to
by the centre as in Figure 2. The background shall be black ( D = 0 , D = 0 , D = 0 ), unless
R G B
otherwise specified.
Centre
h/5
h/5
IEC  459/05
NOTE In the case where the appropriate relationship is confirmed, it is acceptable to measure luminous intensity
direct instead of using the perfect reflecting diffuser.
Figure 2 – Size of colour patch

61966-6  IEC(E) – 11 –
5.3 Input digital data
The relationship between the input digital data, D , D , D of N bits per channel and
R G B
corresponding normalized signal levels R , G , B for calculations shall be
D 
R
i
R =

i
N
2 − 1

D
G

i
G = (1)

i
N
2 − 1


D
B
i

B =
i
N

2 − 1

where the index i denotes the i th measurement step.
NOTE When the input signal is applicable in analogue voltage, the signal level normalized by the maximum input
voltage should correspond to the signal level for each step defined in equation (1).
6 Measurement equipment
6.1 Spectroradiometer
A spectroradiometer with the following specification should be used for measurements.
a) Wavelength range at least 380 nm to 780 nm
b) Field of view between 0,1° and 2,0°
c) Wavelength uncertainty less than 0,5 nm at wavelengths specified by the
manufacturer of the instrument
d) Scanning interval 5 nm or less
e) Bandpass 5 nm or less
f) Repeatability 0,001 in x , y and 0,5 % in luminance (in candela per
square metre) for the light source specified by the
manufacturer of instrument
g) Uncertainty 0,005 in x , y for red, green, blue and white of a standard
CRT display and 4 % in luminance (in candela per square
meter) for white of the CRT display that has a definite
x , y and luminance value
h) Polarization error within 5 %
The ( x , y ) is the CIE 1931 chromaticity coordinate defined in CIE 15.2.
NOTE 1 Periodic calibration should be carried out with a standard source of known spectral power distribution.
NOTE 2 Further technical details of the design, characterization, and calibration of spectroradiometers can be
found in CIE 63 [17] and JIS Z 8724 [7].
NOTE 3 The standard CRT display is referred to because no standard projection display exists. When it is
available, the standard CRT should be replaced by the projection display.
If the spectroradiometer used for measurements does not meet the above specifications, the
name of the model and the specification of the equipment shall be reported, together with the
results of measurements.
———————
Figures in square brackets refer to the bibliography.

– 12 – 61966-6  IEC(E)
6.2 Colorimeter
The colorimeter in Figure 1 should have the following specifications.
a) Field of view Any value between 0,1° and 2,0°
b) Spectral responsivity conforming to the CIE 2° colour-matching function as
defined in ISO/CIE 10527
c) Repeatability  0,002 in x , y and 0,5 % for luminance for a light source
specified by the manufacturer of the instrument
d) Uncertainty  0,005 in x , y for red, green, blue and white of the CRT
display and 4 % in luminance (in candela per square meter)
for white of the CRT display that has a definite x , y and
luminance value
The ( x , y ) is the CIE 1931 chromaticity coordinate defined in CIE 15.2.
NOTE 1 If the original uncertainty of the colorimeter does not meet this recommendation, correction methods are
available to improve the accuracy for the CRT display measurement. (See [4] and [11].)
NOTE 2 The instrument should be calibrated periodically to assure the uncertainty recommendation given in d)
above.
NOTE 3 The standard CRT display is referred to because no standard projection display exists. When it is
available, the standard CRT should be replaced by the projection display.
The readings of the col
...

IEC 61966-6 ®
Edition 1.0 2005-03
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Multimedia systems and equipment – Colour measurement and management –
Part 6: Front projection displays

Systèmes et appareils multimédia – Mesure et gestion de la couleur –
Partie 6: Ecrans de projection frontale

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IEC 61966-6 ®
Edition 1.0 2005-03
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Multimedia systems and equipment – Colour measurement and management –

Part 6: Front projection displays

Systèmes et appareils multimédia – Mesure et gestion de la couleur –

Partie 6: Ecrans de projection frontale

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX U
ICS 17.180.20; 33.160.60 ISBN 978-2-83220-609-6

– 2 – 61966-6  IEC:2005
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 7
4 Letters and symbols . 8
5 Conditions . 9
5.1 Environmental conditions . 9
5.2 Conditions for measurements . 9
5.3 Input digital data . 11
6 Measurement equipment . 11
6.1 Spectroradiometer . 11
6.2 Colorimeter . 12
7 Spectral characteristics and intensity of the primaries and white . 12
7.1 Characteristics to be measured . 12
7.2 Measurement conditions . 12
7.3 Method of measurement . 13
7.4 Presentation of results . 13
8 Basic colorimetric characteristics . 14
8.1 Characteristics to be measured . 14
8.2 Method of measurement . 14
8.3 Presentation of results . 15
9 Tone characteristics . 15
9.1 Characteristics to be measured . 15
9.2 Measurement conditions . 15
9.3 Method of measurement . 15
9.4 Presentation of results . 16
10 Other characteristics . 19
10.1 Inter-channel dependency . 19
10.1.1 Characteristics to be measured . 19
10.1.2 Measurement conditions . 19
10.1.3 Method of measurement . 19
10.1.4 Presentation of results . 22
10.2 Spatial non-uniformity. 23
10.2.1 Characteristics to be measured . 23
10.2.2 Measurement conditions . 23
10.2.3 Method of measurement . 23
10.2.4 Presentation of results . 27

Bibliography . 30

Figure 1 – Equipment arrangement for measurements (side view) . 10
Figure 2 – Size of colour patch . 10
Figure 3 – Example of the spectral radiance distributions r(λ), g(λ),b(λ) . 13

61966-6  IEC:2005 – 3 –
Figure 4 – Measured points and interpolated curves . 16
Figure 5 – Measurement points for spatial non-uniformity (25 points) . 23
Figure 6 – Measurement points for spatial non-uniformity (9points) . 25
Figure 7 – Measurement points for spatial non-uniformity (13 points) . 26

Table 1 – Input data for peak primaries and peak white . 13
Table 2 – Example of reporting form for colours in maximum excitations . 14
Table 3 – Example of reporting form . 15
Table 4 – Example set of basic normalized data for tone characteristics . 18
Table 5 – Digital driving levels to generate colour patches for measurement of
interchannel dependency . 20
Table 6 – Example of normalized tristimulus values (matrix A) . 22
Table 7 – Example of reporting form . 28
Table 8 – Example of reporting form . 28
Table 9 – Example of reporting form . 29

– 4 – 61966-6  IEC:2005
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
MULTIMEDIA SYSTEMS AND EQUIPMENT –
COLOUR MEASUREMENT AND MANAGEMENT –

Part 6: Front projection displays

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
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with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
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4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with an IEC Publication.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 61966-6 has been prepared by technical area 2: Colour
measurement and management, of IEC technical committee 100: Audio, video and multimedia
systems and equipment.
This bilingual version (2013-03) corresponds to the monolingual English version, published in
2005-03.
The text of this standard is based on the following documents:
CDV Report on voting
100/835/CDV 100/915/RVC
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
The French version of this standard has not been voted upon.

61966-6  IEC:2005 – 5 –
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
IEC 61966 consists of the following parts, under the general title Multimedia systems and
equipment – Colour measurement and management:
Part 1: General
Part 2-1: Colour management – Default RGB colour space – sRGB
Part 2-2: Colour management – Extended RGB colour space – scRGB
Part 3: Equipment using cathode ray tubes
Part 4: Equipment using liquid crystal display panels
Part 5: Equipment using plasma display panels
Part 6: Front projection displays
Part 7-1: Colour printers – Reflective prints – RGB inputs
Part 7-2: Colour printers - Reflective prints - CMYK inputs (under consideration)
Part 8: Multimedia colour scanners
Part 9: Digital cameras
Part 10: Quality assessment - Colour image in network systems (under consideration)
Part 11: Quality assessment - Impaired video in network systems (under consideration)
The committee has decided that the contents of this publication will remain unchanged until
the maintenance result date indicated on the IEC web site under "http://webstore.iec.ch" in
the data related to the specific publication. At this date, the publication will be
• reconfirmed;
• withdrawn;
• replaced by a revised edition, or
• amended.
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct
understanding of its contents. Users should therefore print this document using a
colour printer.
– 6 – 61966-6  IEC:2005
INTRODUCTION
The IEC 61966 series of standards defines methods and parameters for colour measurements
and colour management for use in multimedia systems and equipment, applicable to colour
production and reproduction. Part 6 deals with front projection displays.
The methods of measurement standardized in this part are designed to make possible the
objective characterization of colour reproduction of front projection displays which accept red-
green-blue analogue and/or digital signals from electrical input terminals and output light
corresponding to the intended colour. The measured results are intended to be used for the
purpose of equipment-specific colour control in order to attain colour management in open
multimedia systems and should generally be adequate for this purpose. However, in some
cases, it may be necessary to consider additional factors not addressed in this part of
IEC 61966, such as the actual environment in which the front projection display will be used,
to achieve the desired colour reproduction.
Readers of this standard are also encouraged to review IEC 61947-1 and IEC 61947-2, which
apply to the measurement and documentation of key performance criteria for multimedia
projectors.
61966-6  IEC:2005 – 7 –
MULTIMEDIA SYSTEMS AND EQUIPMENT –
COLOUR MEASUREMENT AND MANAGEMENT –

Part 6: Front projection displays

1 Scope
This part of IEC 61966 defines input test signals, measurement conditions, methods of
measurement and reporting of the measured data, to be used for colour characterization and
colour management of front projection displays in multimedia systems.
Colour control within equipment is outside the scope of this part. It does not specify limiting
values for various parameters.
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.
IEC 60050-845:1987, International Electrotechnical Vocabulary (IEV) – Chapter 845:
Lighting/CIE 17.4: 1987, International Lighting Vocabulary (Joint IEC/CIE publication)
IEC 61947 (all parts), Electronic projection – Measurement and documentation of key
performance criteria
ISO/CIE 10527:1991, CIE standard colorimetric observers
CIE 15.2:1986, Colorimetry
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60050-845 and CIE
17.4, as well as the following, apply.
3.1
background
data corresponding to an image surrounding the target colour patch to be measured
3.2
colour control
effort to convert equipment-dependent colour image data to equipment-independent data for a
specific colour space including tone characteristics
3.3
colour patch, test area
square colour image on a virtual screen of the front projection display subject to be measured
for colour reproduction, in which input data for the red, green and blue channels are kept
constant within the image area

– 8 – 61966-6  IEC:2005
3.4
CRT
colorimetrically well-controlled equipment using cathode ray tubes to present colour images
with digital inputs for reference
3.5
effective screen height
vertical dimension of the effective screen area
3.6
effective screen area
area where a picture can be produced
3.7
normalized (image) signal
input signal normalized by its full-scale value, whose level is of interest in calculation and
evaluation of colour control function within front projection display (see also equation (1) in
5.3)
3.8
uncertainty (of measurement)
parameter, associated with the result of a measurement, that characterizes the dispersion of
the values that could reasonably be attributed to the particular quantity subject to
measurement (see also the IEC Guide to the expression of uncertainty in measurement,1995)
3.9
virtual screen
perfect reflecting diffuser-to-image input data
4 Letters and symbols
The notations consistently adopted in this part of IEC 61966 are summarized below.
A display area ratio
N number of bits in digital data for each channel
N
M maximum integer for non-negative N -bits system; M = 2 −1
D digital data applied for red channel
R
D digital data applied for green channel
G
D digital data applied for blue channel
B
R normalized input level to red channel
G normalized input level to green channel
B normalized input level to blue channel
one of measured raw data using spectroradiometers and colorimeters corresponding
X
to tristimulus values
Y one of measured raw data using spectroradiometers and colorimeters corresponding
to tristimulus values in candela per square metre
Z one of measured raw data using spectroradiometers and colorimeters corresponding
to tristimulus values
R′ linearized data for red channel taking into account the tone characteristics of the
channel
61966-6  IEC:2005 – 9 –
′
G linearized data for green channel taking into account the tone characteristics of the
channel
′
B linearized data for blue channel taking into account the tone characteristics of the
channel
′
X one of the tristimulus values normalized by Y (candela per square metre) for peak
n
white
Y′ one of the tristimulus values normalized by Y (candela per square metre) for peak
n
white
Y
Z′ one of the tristimulus values normalized by (candela per square metre) for peak
n
white
5 Conditions
5.1 Environmental conditions
All measurements specified in this document shall be carried out in a dark room. Particular
attention should be paid to prevent reflected illumination caused by the ambient objects
(desktop, wall, etc.) and direct illumination from light-emitting indicators of measuring
instruments.
An hour warm-up time should precede this measurement, if not specified by the manufacturer
of the equipment.
The mains voltage and frequency shall be at the rated value specified by the manufacturer. If
the mains voltage fluctuates, a regulated power supply shall be used to maintain the supply
voltage to within ±5 % of the rated value.
Other environmental conditions such as room temperature and relative humidity shall be
reported together with the results of measurements.
If additional environmental conditions are described in the manufacturer’s specifications,
these should be taken into account.
5.2 Conditions for measurements
Contrast, brightness and additional adjustments shall be set to the preset positions specified
by the manufacturer. If the adjustment is set to another position than the preset, the position
or corresponding value shall be reported with the results of measurements.
Geometrical adjustment shall be set to default position.
The arrangement of equipment for measurements shall be as shown in Figure 1. It
incorporates a spectroradiometer or a non-contact colorimeter, depending on the
characteristics to be measured.
The diagonal image size on the screen shall be set to the preset size specified by the
manufacturer. If no size is specified, it shall be set to 102 cm.
The height of front projection display (H) and the distance between the screen and the head
of the front projection display (L) shall be set to the preset positions specified by the
manufacturer. They depend on the screen size.

– 10 – 61966-6  IEC:2005
h
H
L
d
IEC  458/05
Key
1 Screen d Distance between screen and measuring instrument
2 Perfect reflecting diffuser
h Effective screen height
3 Front projection display
H Height projected image
4 Spectroradiometer or colorimeter
L Distance from the screen
Figure 1 – Equipment arrangement for measurements (side view
The instrument optical axis should be perpendicular to the screen. If another measurement
angle is recommended by the manufacturer, it shall be reported together with the results of
measurements. The distance shall be .
d 4h < d < 5,5h
A perfect reflecting diffuser shall be set on the centre of effective screen area.
The measured light shall be that reflected by a perfect reflecting diffuser.
Test signals applied to the red, green, and blue channels shall result in a colour patch of the
size shown in Figure 2 on the screen. The positioning of the colour patch shall be referred to
by the centre as in Figure 2. The background shall be black ( D = 0 , D = 0 , D = 0 ), unless
R G B
otherwise specified.
Centre
h/5
h/5
IEC  459/05
NOTE In the case where the appropriate relationship is confirmed, it is acceptable to measure luminous intensity
direct instead of using the perfect reflecting diffuser.
Figure 2 – Size of colour patch

61966-6  IEC:2005 – 11 –
5.3 Input digital data
The relationship between the input digital data, D , D , D of N bits per channel and
R G B
corresponding normalized signal levels , , for calculations shall be
R G B
D 
R
i
R =

i
N
2 − 1

D
G

i
(1)
G =

i
N
2 − 1


D
B
i

B =
i
N

2 − 1

where the index i denotes the i th measurement step.
NOTE When the input signal is applicable in analogue voltage, the signal level normalized by the maximum input
voltage should correspond to the signal level for each step defined in equation (1).
6 Measurement equipment
6.1 Spectroradiometer
A spectroradiometer with the following specification should be used for measurements.
a) Wavelength range at least 380 nm to 780 nm
b) Field of view between 0,1° and 2,0°
c) Wavelength uncertainty less than 0,5 nm at wavelengths specified by the
manufacturer of the instrument
d) Scanning interval 5 nm or less
e) Bandpass 5 nm or less
f) Repeatability 0,001 in x , y and 0,5 % in luminance (in candela per
square metre) for the light source specified by the
manufacturer of instrument
0,005 in , for red, green, blue and white of a standard
g) Uncertainty x y
CRT display and 4 % in luminance (in candela per square
meter) for white of the CRT display that has a definite
x , y and luminance value
h) Polarization error within 5 %
The ( x , y ) is the CIE 1931 chromaticity coordinate defined in CIE 15.2.
NOTE 1 Periodic calibration should be carried out with a standard source of known spectral power distribution.
NOTE 2 Further technical details of the design, characterization, and calibration of spectroradiometers can be
found in CIE 63 [17] and JIS Z 8724 [7].
NOTE 3 The standard CRT display is referred to because no standard projection display exists. When it is
available, the standard CRT should be replaced by the projection display.
If the spectroradiometer used for measurements does not meet the above specifications, the
name of the model and the specification of the equipment shall be reported, together with the
results of measurements.
———————
Figures in square brackets refer to the bibliography.

– 12 – 61966-6  IEC:2005
6.2 Colorimeter
The colorimeter in Figure 1 should have the following specifications.
a) Field of view Any value between 0,1° and 2,0°
b) Spectral responsivity conforming to the CIE 2° colour-matching function as
defined in ISO/CIE 10527
c) Repeatability  0,002 in x , y and 0,5 % for luminance for a light source
specified by the manufacturer of the instrument
d) Uncertainty  0,005 in x , y for red, green, blue and white of the CRT
display and 4 % in luminance (in candela per square meter)
for white of the CRT display that has a definite x , y and
luminance value
The ( x , y ) is the CIE 1931 chromaticity coordinate defined in CIE 15.2.
NOTE 1 If the original uncertainty of the colorimeter does not meet this recommendation, correction methods are
available to improve the accuracy for the CRT display measurement. (See [4] and [11].)
NOTE 2 The instrument should be calibrated periodically to assure the uncertainty recommendation given in d)
above.
NOTE 3 The standard CRT display is referred to because no standard projection display exists. When it is
available, the standard CRT should be replaced by the projection display.
The readings of the colorimeter, X , Y (in candela per square meter), and Z shall be
normalized by the luminance level of a peak neutral colour (white), Y (in candela per square
n
metre), as follows:

X
′
X =

Y
n


Y

Y′ = (2)

Y
n


Z
Z′ =

Y 
n 
If the colorimeter used for measurements does not meet the above specifications, the name of
the model and the specification of the equipment shall be reported, together with the results
of measurements.
7 Spectral characteristics and intensity of the primaries and white
7.1 Characteristics to be measured
Spectral radiance distributions and corresponding tristimulus values for the peak of three
primaries, red-green-blue, and white.
7.2 Measurement conditions
a) The arrangement of equipment shall be as in Figure 1 with the spectroradiometer.
b) The colour signal shall be so generated that the colour patch is positioned at the centre of
the screen under measurement.
c) Digital data for the background shall be D = 0 , D = 0 , D = 0 .
R G B
61966-6  IEC:2005 – 13 –
7.3 Method of measurement
a) The centred colour patches shall be generated following the measurement steps as shown
N
in Table 1, where M = 2 − 1 and N is the number of bits.
Table 1 – Input data for peak primaries and peak white
Steps Colours D D
D
R B
G
1 Peak red M 0 0
2 Peak green 0 0
M
3 Peak blue
0 0 M
4 Peak white M M M
b) Spectral radiance distributions r(λ), g(λ),b(λ), w(λ) for peak red, green, blue and white
images on the screen shall be measured successively by the spectroradiometer.
c) Readings of the spectroradiometer with an emulation function of colorimeters X , Y ,
C′ C′
Z shall also be noted, where the suffix C corresponds to R , G , B for primary colours
C′
and to W for the peak white, respectively.
7.4 Presentation of results
a) The measured data for spectral radiance distributions shall be reported for the peak
colours red, green, blue, and white.
b) The spectral radiance distributions r(λ), g(λ),b(λ) shall be plotted for the peak colours red,
green, and blue, respectively, as illustrated in Figure 3.
c) The readings of the spectroradiometer X , Y , Z for peak red, green, blue and white
C′ C′ C′
shall be reported as a table as shown in Table 2.

0,016 0
0,014 0
g(λ)
0,012 0
b(λ)
0,010 0
0,008 0
0,006 0
r(λ)
0,004 0
0,002 0
0,000 0
380 430 480 530 580 630 680 730 780
Wavelength  nm
IEC  460/05
Figure 3 – An example of the spectral radiance distributions
r(λ), g(λ),b(λ)
–2 –1 –1
Radiance (W m sr nm )
– 14 – 61966-6  IEC:2005
Table 2 – Example of reporting form for colours in maximum excitations
Steps Colours
X Y (cd/m ) Z
1 Peak red 159,20 95,07 4,58
2 Peak green 113,60 243,30 23,59
3 Peak blue 71,82 16,84 378,60
4 Peak white 509,60 548,60 647,60

8 Basic colorimetric characteristics
8.1 Characteristics to be measured
Linear relation between maximum input excitation and the tristimulus values of light output.
8.2 Method of measurement
a) The reported results of measurement in 7.4 shall be used to obtain tristimulus values to
characterize the three primaries, red-green-blue, and white. The luminance in cd/m shall
be normalized as follows for red, green, blue and white replacing the suffix C by R , G , B ,
:
W

X
' C
X =
C 
Y
n


Y

' C
Y = (3)
C 
Y
n


Z
' C
Z = 
C
Y 
n

where the normalization factor Y is the measured luminance value for peak white Y
w
n
which is reported in Table 2.
b) The CIE 1931 xy chromaticity coordinate values, x , y shall be calculated for primary
C C
colours and for white as defined in CIE 15.2, where the suffix C corresponds to R , G ,
B for primary colours, and W for white, respectively.
'

X
C
x =

C
' ' '
X + Y + Z 
C C C

'

Y
C
(4)

y =
C
' ' '

X + Y + Z
C C C



z = 1− x − y
C C C

c) The elements of a 3× 3 matrix, S , defined as
X ' R′
   
   
Y' = S G′ (5)
   
   
Z' B′
   
shall be decided as in
 x y x y x y  S 0 0 
R R G G B B R
  
S = 1 1 1 0 S 0 (6)
  
G
  
z y z y z y 0 0 S
R R G G B B B
  
where S , S , S are solutions of equation (7);
R G B
61966-6  IEC:2005 – 15 –
 x y x y x y  S   x y 
R R G G B B R W W
    
1 1 1 S = 1 (7)
    
G
    
z y z y z y S z y
R R G G B B B W W
    
8.3 Presentation of results
a) The tristimulus values multiplied by 100 and the CIE 1931 chromaticity coordinates
xy
values shall be reported as a table, as shown in Table 3.
Table 3 – Example of reporting form
Tristimulus values Chromaticity coordinates
Colours
y
′ ′ ′ x
X Y Z
Peak red
29,02 17,33 0,84 0,615 0,367
Peak green 20,71 44,35 4,30 0,299 0,639
Peak blue 13,09 3,07 69,01 0,154 0,036
Peak white 92,89 100,00 118,05 0,299 0,321

∗ ∗ ∗
′ ′
NOTE CIE 1976 UCS coordinate values, u , v and CIELAB values, L , a , b may additionally be reported.

b) The coefficient matrix shall be reported as shown.
 0,383 1 0,337 3 0,208 6
 
S = 0,228 8 0,722 3 0,048 9 (8)
 
 
0,011 0 0,070 0 1,099 4
 
c) The correlated colour temperature T defined in 5.5 of CIE 15.2, for peak white shall
CP
also be calculated and reported in Kelvins, together with the deviation Δ .
uv
NOTE For the actual procedure to calculate correlated colour temperatures, refer to [16].
9 Tone characteristics
9.1 Characteristics to be measured
Non-linear transfer relationship between the normalized input signal level applied to each of
the red, green and blue channels and the normalized luminance level of a front projection
display.
9.2 Measurement conditions
a) The arrangement of the equipment shall be as in Figure 1.
b) The input data D , D , D for measurement step i shall be so applied as to generate
R G B
colour patches (see Figure 2) positioned at the centre of the screen under measurement.
c) The digital input data for the background shall be , , .
D = 0 D = 0 D = 0
R G B
NOTE 1 For the relationship between digital data D , D , D and values of R , G , B , see equation (1) in 5.3.
R G B
NOTE 2 If analogue input is used, the input signal should be at the same level as in the digital data.
9.3 Method of measurement
a) The centred colour patches shall be displayed for equally stepped values of input data
1 2
N N N
from 0, 2 , 2 ,. , to M = 2 − 1, where m + 1 is the number of data, and should be
m m
– 16 – 61966-6  IEC:2005
more than 32, and N is the number of bits, for each of the three channels. For the red
channel measurement, D = D = 0 , for the green channel, D = D = 0 , and for the
G B R B
blue channel, D = D = 0 shall be kept, respectively.
R G
b) The readings of the colorimeter for each colour patch on the screen shall be recorded
i i i
successively and noted as X , Y , Z where the suffix C should be replaced by R , G
C
C C
and B for red, green, blue channels, respectively; and a superfix i corresponds to
measurement steps, i = 0,1,2,,, m .
c) The measured tristimulus values shall be normalized by the values corresponding to the
N
maximum excitation for the last step m with input data M = 2 − 1.
i

X
'' C

X =
iC
m

X
C

i

Y

'' C
Y = (9)

iC
m
Y

C

i
Z

'' C
Z =

iC
m
Z

C 
where the suffix C shall be replaced by each of R , G and B .
9.4 Presentation of results
'' '' ''
The measured and normalized data X ,Y and Z for i = 0 to i = m shall be reported as plots
i i i
for C = R , G , B with interpolated non-linear transfer relation, as shown in Figures 4a, 4b
and 4c.
1,0
X"
0,9
Y"
Z"
0,8
0,7
0,6
0,5
0,4
0,3
0,2
0,1
0,0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1,0
Normalized input for red channel
IEC  461/05
Figure 4a – Red channel
Normalized light output
61966-6  IEC:2005 – 17 –
1,0
X"
Y"
0,9
Z"
0,8
0,7
0,6
0,5
0,4
0,3
0,2
0,1
0,0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1,0
Normalized input for green channel
IEC  462/05
Figure 4b –Green channel
1,0
X"
Y"
0,9
Z"
0,8
0,7
0,6
0,5
0,4
0,3
0,2
0,1
0,0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1,0
Normalized input for blue channel
IEC  463/05
Figure 4c – Blue channel
Figure 4 – Measured points and interpolated curves
Normalized light output
Normalized light output
– 18 – 61966-6  IEC:2005
The basic normalized data defined by equation (9) in item c) of 9.3 shall also be reported as a
table as shown in Table 4.
Table 4 – Example set of basic normalized data for tone characteristics
i
′′ ′′ ′′ ′′ ′′ ′′ ′′ ′′ ′′
X Y Z X Y Z X Y Z
R R R G G G B B B
0 0,0111 0,0187 0,9636 0,0101 0,0045 0,1297 0,0169 0,0669 0,0066
1 0,0136 0,0214 0,9657 0,0127 0,0069 0,1327 0,0180 0,0680 0,0076
2 0,0162 0,0240 0,9679 0,0152 0,0094 0,1357 0,0190 0,0692 0,0086
3 0,0302 0,0384 0,9722 0,0233 0,0174 0,1427 0,0233 0,0732 0,0129
4 0,0441 0,0527 0,9764 0,0315 0,0253 0,1496 0,0276 0,0773 0,0173
5 0,0614 0,0702 0,9786 0,0440 0,0379 0,1610 0,0389 0,0876 0,0287
6 0,0788 0,0877 0,9807 0,0565 0,0504 0,1723 0,0502 0,0979 0,0401
7 0,0961 0,1052 0,9829 0,0691 0,0630 0,1837 0,0615 0,1082 0,0515
8 0,1134 0,1227 0,9850 0,0816 0,0755 0,1951 0,0728 0,1185 0,0629
9 0,1438 0,1534 0,9845 0,1015 0,0956 0,2141 0,0948 0,1382 0,0849
10 0,1742 0,1841 0,9839 0,1215 0,1157 0,2331 0,1167 0,1580 0,1068
11 0,2046 0,2148 0,9834 0,1414 0,1358 0,2522 0,1387 0,1777 0,1287
12 0,2351 0,2455 0,9829 0,1613 0,1558 0,2712 0,1606 0,1974 0,1507
13 0,2711 0,2816 0,9845 0,1867 0,1813 0,2956 0,1870 0,2210 0,1773
14 0,3072 0,3177 0,9861 0,2120 0,2067 0,3200 0,2134 0,2446 0,2038
15 0,3433 0,3539 0,9877 0,2374 0,2321 0,3445 0,2398 0,2683 0,2304
16 0,3794 0,3900 0,9893 0,2627 0,2576 0,3689 0,2661 0,2919 0,2570
17 0,4263 0,4364 0,9882 0,2983 0,2938 0,4027 0,3043 0,3269 0,2958
18 0,4732 0,4827 0,9872 0,3340 0,3301 0,4366 0,3425 0,3619 0,3346
19 0,5201 0,5291 0,9861 0,3696 0,3663 0,4705 0,3807 0,3968 0,3733
20 0,5670 0,5755 0,9850 0,4052 0,4026 0,5043 0,4189 0,4318 0,4121
21 0,6134 0,6214 0,9866 0,4489 0,4470 0,5432 0,4638 0,4732 0,4575
22 0,6598 0,6673 0,9882 0,4927 0,4913 0,5821 0,5087 0,5146 0,5030
23 0,7062 0,7132 0,9898 0,5364 0,5357 0,6210 0,5535 0,5560 0,5484
24 0,7526 0,7591 0,9914 0,5802 0,5801 0,6599 0,5984 0,5974 0,5938
25 0,7848 0,7907 0,9898 0,6226 0,6228 0,6960 0,6457 0,6437 0,6422
26 0,8170 0,8223 0,9882 0,6651 0,6656 0,7320 0,6929 0,6899 0,6905
27 0,8492 0,8539 0,9866 0,7075 0,7083 0,7680 0,7402 0,7362 0,7389
28 0,8814 0,8855 0,9850 0,7500 0,7511 0,8040 0,7874 0,7825 0,7873
29 0,9175 0,9200 0,9872 0,8066 0,8074 0,8501 0,8386 0,8344 0,8390
30 0,9536 0,9545 0,9893 0,8632 0,8636 0,8963 0,8898 0,8864 0,8907
31 0,9768 0,9773 0,9946 0,9316 0,9318 0,9481 0,9449 0,9432 0,9453
32 1,0000 1,0000 1,0000 1,0000 1,0000 1,0000 1,0000 1,0000 1,0000

61966-6  IEC:2005 – 19 –
10 Other characteristics
10.1 Inter-channel dependency
10.1.1 Characteristics to be measured
Inter-channel relationship between input data and tristimulus values, X′ , Y′ , Z′ of displayed
colours.
The relationship depending upon channel interaction shall be defined as follows:
 
 
R'


 
G'
 '
 
X
 
 B' 
'
 
Y = ST (10)
 
 
R' G'
'
 
Z
 
 
  G' B'
 
B' R'
 
 
R' G' B'
 
where the variables ′ , ′ , ′ are data obtained by interpolation of measured data which are
R G B
reported as X′′ , X′′ , X′′ in Table 4, and dependent variables X′ , Y′ , Z′ are measured and
R G B
normalized tristimulus values of light output, as in 8.2. In equation (10), S and T are 3× 3 and
3× 8 matrices respectively defined as follows:
s s s
 
11 12 13
 
S = s s s (11)
 
21 22 23
 
s s s
 31 32 33 
t t t t t t t t 
0X 1X 2X 3X 4X 5X 6X 7X
 
T = t t t t t t t t (12)
 
0Y 1Y 2Y 3Y 4Y 5Y 6Y 7Y
 
t t t t t t t t
0Z 1Z 2Z 3Z 4Z 5Z 6Z 7Z
 
NOTE The matrix S is the dominant relation obtained and reported in 8.3, and the matrix T defines cross-channel
relations among red-green-blue channels.
10.1.2 Measurement conditions
a) The arrangement of the equipment shall be as in Figure 1.
b) The colour signal shall be so applied as to generate the colour patch positioned at the
centre of the screen under measurement.
c) The input data for the background shall be D = 0 , D = 0 , D = 0 .
R G B
10.1.3 Method of measurement
a) The centred colour patches shall be displayed with the input data following the
measurement steps, as shown in Table 5, for 32 colours.

– 20 – 61966-6  IEC:2005
Table 5 – Digital driving levels to generate colour patches
for measurement of interchannel dependency
Step. i Colour D
D D
G
R B
D D D
1 grey 1
1 1 1
D D D
2 grey 2
2 2 2
D D D
3 grey 3
3 3 3
D D D
4 grey 4
4 4 4
D D D
5 grey 5
5 5 5
D D D
6 grey 6
6 6 6
D D D
7 grey 7
7 7 7
D D D
8 grey 8
8 8 8
9 red 1 D D D
4 0 0
10 red 2 D D D
6 2 2
11 red 3 D D D
8 0 0
12 red 4 D D D
8 4 4
13 green 1 D D D
0 4 0
14 green 2 D D D
2 6 2
15 green 3 D D D
0 8 0
16 green 4 D D D
4 8 4
17 blue 1 D D D
0 0 4
18 blue 2 D D D
2 2 6
61966-6  IEC:2005 – 21 –
Table 5 (continued)
Step. i Colour
D D D
R G B
19 blue 3 D D D
0 0 8
20 blue 4 D D D
4 4 8
21 yellow 1 D D D
4 4 0
22 yellow 2 D D D
6 6 2
23 yellow 3 D D D
8 8 0
24 yellow 4 D D D
8 8 4
25 magenta 1 D D D
4 0 4
26 magenta 2 D D D
6 2 6
27 magenta 3 D D D
8 0 8
28 magenta 4 D D D
8 4 8
29 cyan 1 D D D
0 4 4
30 cyan 2 D D D
2 6 6
31 cyan 3 D D D
0 8 8
32 cyan 4 D D D
4 8 8
In Table 5, the values of data D shall be
k
N−3

2 k     for k = 0,.,7,
D = (13)

k
N−3

2 k − 1  for k = 8.

where N is the number of bits for each channel.

NOTE If the analogue input is used, the input signal should be of the same level as the digital data.
b) The tristimulus values X′ , Y′ , Z′ normalized in accordance with equation (2), shall
i i i
= 1 to = 32 for all colour p
...