IEC 61966-9:2003

Multimedia systems and equipment - Colour measurement and management - Part 9: Digital cameras

IEC 61966-9:2003 defines methods of measurement designed to make possible the objective performance assessment and characterization of the colour reproduction of digital cameras which can capture colour still and moving images, and output colour information corresponding to red - green - blue digital image data. The measured results are intended to be used for the purpose of colour management in multimedia systems, typically in the Internet. This bilingual version (2013-03) corresponds to the monolingual English version, published in 2003-11. This second edition cancels and replaces the first edition published in 2000. It includes the following significant technical changes:
- In the light of issuing IEC 61966-2-2, the relevant reference IEC 61966-2-1 in Annex C has been replaced by IEC 61966-2-2 together with sRGB by scRGB.
- The previous Annex C has been replaced by the new Annex C where the previous Figure C.1 has been deleted.

Systèmes et appareils multimédia - Mesure et gestion de la couleur - Partie 9: Appareils numériques de prise de vue

La CEI 61966-9:2003 définit les méthodes de mesure pour permettre l'évaluation objective de la performance et la caractérisation de la reproduction des couleurs des appareils numériques de prise de vue qui peuvent prendre des images en couleur fixes et animées, et des informations de couleur en sortie correspondant aux données numériques d'images rouge, vert et bleu. Les résultats mesurés sont destinés à être utilisés pour la gestion de la couleur dans les systèmes multimédia, généralement sur Internet. Cette deuxième édition annule et remplace la première édition parue en 2000. Elle contient les modifications techniques significatives suivantes:
- Compte tenu de la publication de la CEI 61966-2-2, la référence correspondante, à la CEI 61966-2-1 de l'Annexe C, a été remplacé par CEI 61966-2-2 et sRVB par scRVB.
- L'ancienne Annexe C a été remplacée par la nouvelle Annexe C, dans laquelle l'ancienne Figure C.1 a été supprimée. La présente version bilingue (2013-03) correspond à la version anglaise monolingue publiée en 2003-11.

General Information

• Status: Published
• Publication Date: 18-Nov-2003
• ICS: 33.160.60 - Multimedia systems and teleconferencing equipment
• ICS: 35.040 - Information coding
• ICS: 37.040.01 - Photography in general
• Technical Committee: TC 100 - Audio, video and multimedia systems and equipment
• Current Stage: PPUB - Publication issued
• Start Date: 30-Jun-2004
• Completion Date: 19-Nov-2003

Standards Content (Sample)

IEC 61966-9
®

Edition 2.0 2003-11
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside


Multimedia systems and equipment – Colour measurement and management –
Part 9: Digital cameras

Systèmes et appareils multimédia – Mesure et gestion de la couleur –
Partie 9: Appareils numériques de prise de vue


IEC 61966-9:2003

---------------------- Page: 1 ----------------------
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IEC 61966-9

®


Edition 2.0 2003-11




INTERNATIONAL



STANDARD




NORME



INTERNATIONALE
colour

inside










Multimedia systems and equipment – Colour measurement and management –

Part 9: Digital cameras




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

Partie 9: Appareils numériques de prise de vue
















INTERNATIONAL

ELECTROTECHNICAL

COMMISSION


COMMISSION

ELECTROTECHNIQUE

PRICE CODE
INTERNATIONALE

CODE PRIX V


ICS 33.160.60; 35.040; 37.040 ISBN 978-2-83220-607-2



Warning! Make sure that you obtained this publication from an authorized distributor.

Attention! Veuillez vous assurer que vous avez obtenu cette publication via un distributeur agréé.

® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale

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– 2 – 61966-9  IEC:2003
CONTENTS
FOREWORD . 4

1 Scope . 6
2 Normative references. 6
3 Terms and definitions . 7
4 Conditions . 7
4.1 Environmental conditions . 7
4.2 Conditions of measurements . 7
5 Measurement equipment . 9
5.1 Spectral light source . 9
5.2 Colour temperature conversion filter . 9
5.3 Dark box . 9
5.4 Test charts . 11
5.5 Radiance meter . 13
5.6 Spectro-radiometer . 14
5.7 Luminance meter . 14
6 Tone characteristics . 14
6.1 Characteristics to be measured . 14
6.2 Measurement conditions . 14
6.3 Method of measurement . 15
6.4 Presentation of results . 15
7 Spectral responsivity characteristics. 17
7.1 Characteristics to be measured . 17
7.2 Measurement conditions . 17
7.3 Method of measurement . 17
7.4 Presentation of results . 18
8 Spectral distribution of built-in electronic flash . 19
8.1 Characteristics to be measured . 19
8.2 Measurement conditions . 19
8.3 Method of measurement . 19
8.4 Presentation of results . 20
9 Spatial non-uniformity . 20
9.1 Characteristics to be measured . 20
9.2 Measurement conditions . 20
9.3 Method of measurement . 20
9.4 Presentation of results . 21

Annex A (normative) Letters and symbols . 23
Annex B (informative) Procedure to calculate the inverse function . 24
Annex C (informative) Example of the use of the reported results for colour management . 25
Annex D (normative) Method to compensate spectral responsivity characteristics at the
neutral point . 28
Annex E (informative) Automated extraction of data from the test chart image . 29

Bibliography . 31

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61966-9  IEC:2003 – 3 –

Figure 1 – Equipment arrangement for measurements . 8
Figure 2 – Dark box. 10
Figure 3 – Test chart 1 . 11
Figure 4 – Test chart 2 with replaceable chip i . 12
Figure 5 – Test chart 3 . 12
Figure 6 – Example plot of tone characteristics (correlated colour temperature: 5 500 K) . 16
Figure 7 – Example of spectral responsivity characteristics (correlated colour
temperature: 5 500 K) . 19
Figure 8 – Example of the spectral distribution characteristics of a built-in electronic
flash . 20
Figure 9 – Equipment arrangement for measurement of spatial non-uniformity . 21
Figure C.1 – An example of spectral responsivity controlled to approximate the ideal
scRGB characteristics superimposed as the broken curves . 27
Figure E.1 – Example to compare a typical optical viewfinder area and the
corresponding image sensible area (outer rectangle) . 29
Figure E.2 – Test chart with extended orientation markers . 29

Table 1 – Nominal reflectances of the grey-scale section and the grey chips . 13
Table 2 – Example of tone characteristics (correlated colour temperature: 5 500 K) . 16
Table 3 – An example of reporting form for spatial non-uniformity . 22

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– 4 – 61966-9  IEC:2003
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

MULTIMEDIA SYSTEMS AND EQUIPMENT –
COLOUR MEASUREMENT AND MANAGEMENT –

Part 9: Digital cameras


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
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
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with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
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5) IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
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6) All users should ensure that they have the latest edition of this publication.
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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 61966-9 has been prepared by IEC technical committee 100: Audio,
video and multimedia systems and equipment.
This bilingual version (2013-03) corresponds to the monolingual English version, published in
2003-11.
This second edition cancels and replaces the first edition published in 2000. This edition
includes the following significant technical changes from the previous edition.
a) In the light of issuing IEC 61966-2-2, the relevant reference IEC 61966-2-1 in Annex C has
been replaced by IEC 61966-2-2 together with sRGB by scRGB.
b) The previous Annex C has been replaced by the new Annex C where the previous Figure
C.1 has been deleted.

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61966-9  IEC:2003 – 5 –
The text of this standard was submitted to the national committees for voting under the Fast
Track Procedure as the following documents:
CDV Report on voting
100/666/CDV 100/722/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.
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 2-0: Colour management
– 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
– Part 8: Multimedia colour scanners
– Part 9: Digital cameras
– Part 10: Quality assessment – Colour image in network systems
– Part 11: Quality assessment – Impaired video in network systems
The committee has decided that the contents of this publication will remain unchanged until
2008. At this date, the publication will be
• reconfirmed;
• withdrawn;
• replaced by a revised edition, or
• amended.

he 'colour inside' logo on the cover page of this publication indicates
IMPORTANT – T
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.

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– 6 – 61966-9  IEC:2003
MULTIMEDIA SYSTEMS AND EQUIPMENT –
COLOUR MEASUREMENT AND MANAGEMENT –

Part 9: Digital cameras



1 Scope
This part of IEC 61966 is applicable to the assessment of colour reproduction of digital
cameras used in open computer systems and similar applications.
A series of methods and parameters for colour measurements and management for use in
multimedia systems and equipment is applicable to the assessment of colour reproduction.
This standard deals with digital cameras to capture colour still images and moving images for
use in multimedia applications.
The methods of measurement standardized in this standard are designed to make possible the
objective performance assessment and characterization of the colour reproduction of digital
cameras which can capture colour still and moving images, and output colour information
corresponding to red – green – blue digital image data. The measured results are intended to
be used for the purpose of colour management in multimedia systems, typically in the Internet.
This standard defines test charts, measurement conditions and methods of measurement, so
as to make possible the colour management in open multimedia systems and comprehensive
comparison of the results of measurements for assessment of digital cameras.
Colour control within digital cameras is outwith 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.
IEC 61146-1:1994, Video cameras (PAL/SECAM/NTSC) – Methods of measurement – Part 1:
Non-broadcast single-sensor cameras
IEC 61966-2-1:1999, Multimedia systems and equipment – Colour measurement and
management – Part 2-1: Colour management – Default RGB colour space – sRGB
ISO 2813:1994, Paints and varnishes – Determination of specular gloss of non-metallic paint
films at 20 degrees, 60 degrees and 85 degrees
ISO/CIE 10527:1991, CIE standard colorimetric observers
CIE 17.4:1987, International lighting vocabulary

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61966-9  IEC:2003 – 7 –
3 Terms and definitions
For the purposes of this document, the definitions in IEC 60050-845 and CIE 17.4, as well as
the following definitions, apply.
3.1
colour control
conversion of equipment-dependent colour-image data to equipment-independent data for a
specific colour space including tone characteristics
3.2
digital camera
electronic imaging equipment which can capture colour still and moving images, and outputs
digital image data for red – green – blue channels either by itself or using incorporated colour
control software
4 Conditions
4.1 Environmental conditions
All measurements specified in this standard shall be carried out in a dark room.
Electric power to a digital camera under test shall be supplied using an a.c. adapter or
batteries recommended by the manufacturer.
The mains voltage and frequency applied to the a.c. adapter shall be at the rated value
specified by the manufacturer of the digital camera. When the mains voltage fluctuates,
a stabilizer shall be used to attain a stability value of ±5 % of the rated value.
Other environmental conditions such as temperature and relative humidity shall be reported,
together with the results of measurement.
For additional environmental conditions not specified in this subclause, if any, the speci-
fications of the manufacturer of the digital camera shall be taken into account.
4.2 Conditions of measurements
4.2.1 Measurement arrangement
Unless otherwise specified, a shooting object shall be a test chart with the dark box shown in
Figure 1. The specifications for the centre hole of the chart are given in Figure 3. Relative
positions shall be selected to prevent unnecessary glare from the diffuser.
NOTE The spectral light source consisting of the lamp, the iris, the monochromator, the optical fibre and the
diffuser may be configured in other ways, provided that the required specifications are met.

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– 8 – 61966-9  IEC:2003
Main lamp
Colour temperature
conversion filter
Test chart 1
Digital camera
under test
Diffuser
Dark box
Hole
Auxiliary lamp
Main lamp
Iris
Optical fibre
Monochromator
Lamp
Spectral light source

IEC  612/2000

Figure 1 – Equipment arrangement for measurements
4.2.2 Illumination
Illumination of the test charts shall be performed by two or four main lamps and one auxiliary
lamp depending on the characteristics to be measured. Incident lights from the main lamps
shall be 45° relative to the surface of the test chart. An auxiliary lamp to illuminate the diffuser
in Figure 1 is used only for the measurement specified in Clause 7. The diffuser shall not be
directly illuminated by the main lamps. The main lamps and the auxiliary lamp shall be halogen
lamps with a well-regulated power supply.
The correlated colour temperature of the lamps shall be 3 100 K ± 100 K as specified in
IEC 61146-1. The non-uniformity of illumination shall be less than 5 %. The average
illuminance on the test chart shall be 2 000 lx ± 100 lx.
4.2.3 Shooting conditions
The optical axis of the digital camera under test shall coincide with the normal to the test chart.
If the digital camera under test is equipped with a zoom lens, the distance between the test
chart and the digital camera under test, unless otherwise specified, shall be approximately
1,5 m. The zooming shall be adjusted so that the horizontal and vertical markers fit within the
full frame of an image area.
If the digital camera under test is not equipped with a zoom lens, the distance between the test
chart and the digital camera under test, unless otherwise specified, shall be adjusted so that
the horizontal and vertical markers fit within the full frame of an image area.

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61966-9  IEC:2003 – 9 –
4.2.4 Digital image data
The red – green – blue data necessary for the calculation and characterization of the digital
camera under measurement shall be acquired and recorded depending on the cases described
below.
a) If red – green – blue digital image data are obtained direct from the digital camera under
test, the values shall be recorded.
b) If red – green – blue digital image data are not directly obtainable, they should be
calculated by the manufacturer’s driver software.
c) If red – green – blue digital image data are calculated by any independent application
software on the digital camera under measurement, the name and version of the software
shall be reported together with the values.
5 Measurement equipment
5.1 Spectral light source
The spectral light source consists of a halogen lamp powered by a well-regulated d.c. electric
power source, an iris, a monochromator and an optical fibre with a diffuser as in Figure 1.
Specifications of the constituent parts of the equipment arrangement should be as follows.
a) Output of spectral light source
1
1) Diameter of the diffuser: approximately h
45
2
2) Radiance: more than 10 mW/sr/m
3) Stability of light output: within ±0,5 %
NOTE An integrating sphere may be incorporated to increase uniformity.
b) Monochromator
1) Wavelength range: including from 380 nm to 780 nm
1
2) Spectral bandwidth: 5 nm (FWHM) , triangle
3) Wavelength accuracy: ±0,5 nm
–4
4) Stray light: less than 10
NOTE Higher-order spectra from the monochromator should be removed.
5.2 Colour temperature conversion filter
–1
The amount of reciprocal correlated colour temperature change shall be –140 MK in order to
achieve 5 500 K ± 300 K.

5.3 Dark box
The dark box for the measurements should be as shown in Figure 2. The reflectance of the
inside of the dark box shall be less than 2 %. The accuracy of the dimensions should be within
1
. The geometrical specification of the holes whose positions are designated by “0” shall
± h
50
be as in Figure 3.
___________
1
 FWHM stands for full-width half maximum.

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– 10 – 61966-9  IEC:2003
2h / 3
Test chart 1
Hole
Hole
h
A'
A
Hole

IEC  2650/03

Figure 2 – Dark box

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61966-9  IEC:2003 – 11 –
5.4 Test charts
a) The specular gloss at 60° shall be less than 2,5 %, according to ISO 2813, for all test charts.
The geometric specification of the test charts shall be as shown in Figures 3, 4 and 5. The
1
.
accuracy of the dimensions should be within ± h
50
h / 18 h / 18
h / 36 h / 36 h / 12
h / 12
h / 9

(w− 4h / 9)/ 2
(w− 4h / 9)/ 2
h / 6
h / 6
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
h / 9
15 0 15
h / 9
h
h / 9
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0

h / 6

h / 6
(w− 8h / 9)/ 2
(w− 8h / 9)/ 2
8h / 9
w
IEC  614/2000

Figure 3 – Test chart 1

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– 12 – 61966-9  IEC:2003

Background
h / 18
(reflectance is 18 %)
Grey chip (No. i)
h / 9
h / 18

h / 9
IEC  2651/03

Figure 4 – Test chart 2 with replaceable chip i



h / 5

h / 5

h / 5 h
5
h /
h / 5

2h / 15
w / 5 w / 5 w / 5 w / 5 w / 5

w

IEC  616/2000

Figure 5 – Test chart 3
b) Test chart 3 in Figure 5 shall be the white chart with a nominal reflectance of 88,1 %.
It shall be superimposed with a rectangular grid. The designation of position j in Figure 5
shall be numbered from the top left to the bottom right for the centre of each rectangular
area as j = 1 to 25.
c) The reflectances of the grey steps in test chart 1 shall have the values specified in Table 1,
where the positions designated by “0” are holes.

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61966-9  IEC:2003 – 13 –
Table 1 – Nominal reflectances of the grey-scale section and the grey chips
Reflectance (%)
i

0 0,0(hole)
1 2,0
2 4,0
3 6,0
4 8,0
5 10,3
6 14,7
7 19,8
8 25,8
9 32,5
10 39,9
11 48,1
12 57,0
13 66,6
14 77,0
15 88,1
Background 18,0

5.5 Radiance meter
A radiance meter with the following specification should be used for the measurements of the
output from the spectral light source.
a) Wavelength range: from 380 nm to 780 nm
2 2
b) Measurable range:
from 1 μW/sr/m to 1 W/sr/m
c) Relative accuracy:
±5 % (from 380 nm to 780 nm)
d) Linearity:
±2 %
e) Measurement less than 0,5 %
resolution:

NOTE 1 Radiance can be measured with an irradiance meter at a known distance from a source. A spectro-
radiometer in radiance geometry can also be
...