1

ACTIVITY REPORT

DIVISION 1

COMMISSION INTERNATIONALE DE L’ECLAIRAGE INTERNATIONAL COMMISSION

ON ILLUMINATION

INTERNATIONALE BELEUCHTUNGSKOMMISSION

VISION AND COLOUR

February 2012

Director: Prof Ronnier Luo (GB)

Assoc Director – Vision Dr Miyoshi Ayama (JP)

Assoc. Director – Colour Dr Ellen Carter (US)

Editor Dr Phil Green (GB)

Secretary Dr Michael Pointer (GB) mrpointer@btinternet.com

This report presents an overview of the status of CIE Division 1 - Vision and Color since the last Activity Report that was issued in February 2011. The annual meeting of Division 1 was held in Sun City, South Africa on 14-15 June 2011. The meeting was attended by 4 of the Division officers, representatives of 14 of the 34 member countries, 17 TC chairs and reporters, and approximately 24 guests.

The following Technical Committees met in Sun City: TC1-69 Colour rendition of white light sources TC1-76 Unique hue data TC1-80 Research methods for psychophysical studies of brightness judgments

The following activities were closed in Sun City: TC1-27 Colour appearance for reflection/VDU comparison TC1-41 Extension of V TC1-44 Practical daylight simulators for colorimetry TC1-58 Visual performance in the mesopic range TC1-72 Measurement of appearance network: MApNet TC1-79 Limits of normal colour vision R1-36 Action spectra for glare R1-37 Definition of the visual field for conspicuity R1-48 Colour emotion and harmony

And the following activities were started in Sun City: TC1-83 Visual aspects of time-modulated lighting systems: Dragan Sekulovski NL TC1-84 Definition of visual field for conspicuity: Nana Itoh JP TC1-85 Update CIE Publication 15:2004 Colorimetry: Janos Schanda HU TC1-86 Models of colour emotion and harmony: Li-Chen Ou TW TC1-87 New aspects of colour rendering: Mike Pointer GB R1-53 Gloss perception and measurement R1-54 Variability in colour-matching functions

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R1-55 Enhancement of images for colour defective observers R1-56 Skin colour database R1-57 Border between luminous and blackish colours

In addition, a cross-division TC: TC1-xx Standard on mesopic photometry and guidelines for defining photometric values in the mesopic region (Liisa Halonen FI) was started but has yet to be allocated a number by the Central Bureau.

The following Division 1 publications have appeared during the last year:

CIE 196:2011: CIE Guide to Increase Accessibility in Light and Lighting CIE 195:2011: Specification of Colour Appearance for Reflective Media and Self-Luminous Display Comparison CIE 200:2011: CIE Supplementary System of Photometry CIE S 014-3/E:2011: Colorimetry - Part 3: Calculation of CIE Tristimulus Values

In addition, CIE S 017/E:2011 ILV: International Lighting Vocabulary was published in August 2011.

A summary of the status of each of the Technical Committees in Division 1 is included in this report together with summaries from the Reporters and Liaisons. The reports from the Vision Section are presented first, followed by those from the Colour Section and then the Liaison reports.

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VISION SECTION: TECHNICAL COMMITTEES

TC1-36 (V) Fundamental Chromaticity Diagram with Physiologically Significant Axes

Established: 1991

Terms of Reference:

To establish a chromaticity diagram of which the coordinates correspond to physiologically significant axes.

Chairman: F Viénot FR

Members: D MacLeod US, JD Mollon GB, JD Moreland GB, Y Nakano JP, J Pokorny US,

LT Sharpe DE, A Stockman GB, A Valberg NO, PL Walraven NL, J Wold NO

Consultants: H Scheibner DE, P Trezona GB, and H Yaguchi JP

Part I of the report has been published under the reference CIE Document 170-1:2006. Part II is being prepared. 1. A TC “subcommittee” (TC “subcommittee” = Mollon, Moreland, Pokorny, Valberg, Viénot, Wold)

met at ICVS, in Kongsberg, Norway, July 2011. 2. Part II of the report was sent to TC members and Division 1 officers in July 2011, with the

following content:

Introduction to Part II

Chapter 6. Photometric aspects; the choice of the spectral luminous efficiency functions VLM(λ) and VLM,10(λ) The photopic spectral luminous efficiency functions VLM(λ) and VLM,10(λ) are

VLM (λ) = 0,68990272 )λ(l + 0,34832189 )λ(m

V10(λ) = 0,69283932 )λ(10l + 0,34967567 )λ(10m

The term “LM-luminance” refers to the weighted contribution of L- and M-cones to the luminance.

Chapter 7. Chromaticity diagrams 7.1. The MacLeod-Boynton Chromaticity Diagram

In the MacLeod-Boynton Chromaticity Diagram, the tristimulus values are given by:

)λ(l = 0,68990272 )λ(l / (0,68990272 )λ(l + 0,34832189 )λ(m ),

)λ(m = 0,34832189 )λ(m / (0,68990272 )λ(l + 0,34832189 )λ(m ),

and )λ(s = 0,0371097 )λ(s / (0,68990272 l )λ(l + 0,34832189 )λ(m )

)λ(10l = 0,69283932 )λ(10l / (0,69283932 )λ(10l + 0,34967567 )λ(10m ),

)λ(10m = 0,34967567 )λ(10m / (0,69283932 )λ(10l + 0,34967567 )λ(10m ),

and )λ(10s = 0,0554786 )λ(10s / (0,69283932 l )λ(10l + 0,34967567 )λ(10m )

7.2. Development of XYZ representations of the cone fundamentals based upon the principles of the CIE standard colorimetric systems

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)λ(

)λ(

)λ(

)λ(

)λ(

)λ(

F

F

F

s

m

l

z

y

x

A

)λ(

)λ(

)λ(

)λ(

)λ(

)λ(

10

10

10

10

10,F

10,F

10,F

s

m

l

z

y

x

A

Conclusion to Part II

Tables

3. Unfortunately, we have found some inconsistencies between the numerical values of matrices A

and A10 and the tabulated values of )(),(),( zyx and )(),(),( 101010 zyx . The TC is

working on solving this problem.

TC1-37 (V) Supplementary System of Photometry

Established: 1992

Terms of Reference:

To recommend a system of photometry to assess lights in terms of their comparative brightness relationships at any level.

Chairman: K Sagawa JP

Members: S Ashizawa JP, WB Cowan CA, CM Howard US, M Ikeda JP, JAS Kinney US,

S Kokoschka DE, Y Nakano JP, T Takeuchi JP, PW Trezona GB, F Viénot FR,

H Yaguchi JP, and A Yujiri JP. Also, HJ Schmidt-Clausen DE (Observer).

CIE Publication 200:2011 Supplementary System of Photometry has now been published and this TC will be formally closed at the next meeting of Division 1.

TC1-42 (V) Color Appearance in Peripheral Vision

Established: 1993

Terms of Reference:

To prepare a technical report on color appearance zones for colored lights in terms of unique hues in peripheral vision.

Chairman: M Ayama JP

Members: I Abramov US, M Ayama JP, H Chan US, G Derefeldt SE, L Eriksson SE,

L MacDonald GB, K Okajima JP, A Yujiri JP

No report.

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TC1-60 (V) Contrast Sensitivity Function (CSF) for Detection and Discrimination

Established: 2001

Terms of Reference:

1. To specify a baseline achromatic CSF with its reference conditions and reference observer

2. To specify CSF extensions based on discrimination thresholds, as well as chromatic CSFs for both detection and discrimination

Chairman: M R Pointer GB

Members: D Alleyson FR, M. Artigas Verdes ES, C-C Chen US, M Fairchild US, RV Klassen US,

L MacDonald GB, S McFadden CA, Chaker Larabi FR, E Peli US, AB Watson,

S Wuerger HU, H Yaguchi JP. Observers: L Beke, MH Brill US, D Couzin US,

P Hanselaer BE, N Itoh JP, O da Pos IT, K Richter DE, K Sagawa JP

This committee has been without a Chairman for a number of years and, in order to try to make progress, it was agreed at the Sun City meeting that the Division Secretary should take over as interim chairman. This was strictly to try to progress the work of the committee by trying to find a new chairman but, to date, this has not proved possible. A number of the original members of the TC are of the opinion that the work is still useful in that the outcome according to the Terms of Reference is still required. If however, a new chairman cannot be found by the next meeting of Division 1 in September 2012, the TC will have to be closed. The work was originally requested by Division 8 and contact has been made with this Division to try to find a chairman.

TC1-67 (V) The Effects of Dynamic and Stereo Visual Images on Human Health

Established: 2005

Terms of Reference:

To write a technical report on the physiological and psychophysical effects of dynamic and stereo visual images in terms of photosensitive seizures, visually induced motion sickness and eyestrain.

Chairman: H Ujike JP

Members:

The Technical Report to be developed by this TC has been determined to be as that for photo- sensitive seizures. The draft developed by the editorial group in this TC is under revision in terms of readability. The draft will be circulated among the members early in 2012 for the purpose of developing the final version.

TC1-78 (V) Evaluation of Visual Performance in the Real Lit Environment

Established: 2009

Terms of Reference:

To investigate and report on current research on visual performance that relates to psycho-physical and physiological measurements in the real lit environment, and to produce a plan for future work.

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Chairman: Monica Billger SE

Members: Steve Fotios GB, Frédéric Leloup BE, M. Ronnier Luo GB, Barbara Matusiak NO,

Yoshiki Nakamura JP, Wouter Ryckaert BE, Monica Säter, SE, Jan Wienold DE,

Mark Rea US, Dragon Sekulovski NL, Ingrid Vogel NL

No report.

TC1-80 (V) Research Methods for Psychophysical Studies of Brightness Judgements

Established: 2010

Terms of Reference:

To report on research methods (both research design and statistical analysis) for psychophysical studies of spatial brightness judgements. The aim is to bring best practices from psychology into the wider awareness of people in the lighting community who wish to use such tools in their own work, to avoid errors that plague the existing literature.

Chairman: Steve Fotios

Members: Peter van der Burgt NL, Michelle Gauthier CN, Peter Hanselaer BE,

Kevin Houser US, Sandra Mende DE, Yoshiki Nakamura JP, Keith Niall CN,

Osvaldo da Pos IT, Monica Säter SE, David Simmons GB, Jan Vanrie BE,

Agnes Vidovszky-Nemeth HU, Martijn Withouck BE

This TC was approved at the Vienna meeting in March 2010.

Meetings held: 1. September 2010: 2nd CIE Expert Symposium on Appearance (Ghent, Belgium). 2. July 2011: 27th Session (Sun City, South Africa) There are 20 members, including the chairman, and these have backgrounds in both lighting and psychology: PhD students have been encouraged to join. Progress to date:

Definition of spatial brightness.

Report circulated to classify the four main experimental procedures that have been used in previous research of spatial brightness and to describe precautions needed when employing these.

Report circulated to discuss test conditions (field size, field complexity, evaluation mode etc).

The third part of the final report will be a discussion of statistical methods. Unfortunately the person who had volunteered to lead this had to withdraw. A new volunteer has been sought, although with little success so far. The alternative is to consider removing this from the scope.

TC1-82 (V) The Calculation of Colour Matching Functions as a Function of Age and Field Size

Established: 2010

Terms of Reference:

1. Following on from CIE Technical Report 170, to recommend a procedure for calculating XYZ-like colour marching functions from cone fundamentals, as a

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function of age and field size.

2. To deliver a computer programme for the calculations.

Chairman: Jan-Henrik Wold NO

Members: C F Andersen NO, M Brill US, M Fairchild US, H Fairman US, I Farup NO, C Li CN,

K Richter DE, F Viénot FR, M Withouk BE, Y Yamuchi JP

The TC1-82 is still awaiting the final decisions of the TC1-36. In the meantime, some of the committee members have made some preliminary work on the following:

development of a general procedure for optimization of spectral functions using a fixed number of significant digits (necessary for proper computations of the colour matching functions)

implementation of the TC1-36 procedure for deriving the L-, M- and S-cone fundamentals as

functions of age and field size, i.e. the functions age, fieldsize( )l , age, fieldsize ( )m and age, fieldsize( )s

proposal for a concept for determination of the weighting factors L, age, fieldsize and M, age, fieldsize

to be used in the linear combination of the age and field size dependent cone fundamentals

age, fieldsize( )l and age, fieldsize ( )m and into the age and field size dependent spectral luminous

efficiency function LM, age, fieldsize ( )V .

development of a procedure for determination of the reference curves to be used as target curves in the optimization of the age and field size dependent spectral fundamental chromaticity

coordinates F, age, fieldsize ( )x and F, age, fieldsize ( )y

discussions on which programming language to use for the computer program

Due to the delay in the decisions of TC1-36, the orientation and information package prepared for the TC1-82 members is still not distributed, but as TC1-36 are now very close to an agreement, this can probably be done quite soon (by March 2012). The formal activity of the committee will start once the necessary data are available.

TC1-83 (V) Visual Aspects of Time-Modulated Lighting Systems

Established: 2011

Terms of Reference:

1. To investigate and report on current research on the perception of visual artifacts of temporally modulated lighting systems, including flicker, the stroboscopic effect, ghosting, and digital artifacts.

2. Design methodology and gather data on the visibility of temporal artifacts.

3. Build a model for the visibility of temporal artifacts and their dependence on environmental, demographical and lighting parameters.

Chairman: Dragan Sekulovski NL

Members:

No report.

TC1-84 (V) Definition of Visual Field for Conspicuity

Established: 2011

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Terms of Reference:

To define and classify functional visual fields for universal tasks and develop guidelines for the layout of visual information to increase the visibility of visual signs, displays and markings.

Chairman: Nana Itoh JP

Members:

No report.

TC1-xx (V) Standard on Mesopic Photometry and Guidelines for Defining Photometric Values in the Mesopic Region

Established: 2011

Terms of Reference:

1. To investigate adaptation and viewing conditions in outdoor lighting.

2. To define lighting applications where mesopic photometry should be used.

3. To provide methods and guidelines for calculating photometric values in the mesopic region to prepare a standard on a system of mesopic photometry

Chairman: Liisa Halonen FI

Members:

This cross division TC has yet to be formally established by the CIE Central Bureau.

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VISION SECTION: REPORTERS

R1-40 (V) Scene Dynamic Range

Established: 2006

Terms of Reference:

To investigate the concept of scene dynamic range, the appearance of colors brighter than the adapted white, and adaptation to the dynamic range when viewing, and make recommendations regarding work to be done by the CIE.

Reporter: J Holm US

No report.

R1-49 (V) Above-threshold Pulsed Lights

Established: 2009

Terms of Reference:

To review methods for photometric prediction of the brightness and colour of supra-threshold pulsed signal lights.

Reporter: Malcolm Nicholson GB & Dennis Couzin US

No report.

R-51 (V) Reconciling Maxwell vs. Maximum Saturation Colour Matches

Established: 2010

Terms of Reference:

1. To examine the CIE TR 185 rod-cone model.

2. To examine the viability of the uniqueness of stimulus C for a Maxwell match.

3. To examine the hypothesis of pigment-bleaching distinction between the matching methods.

4. To examine in u’v’ space the Wyszecki & Stiles reported discrepancy of the spectrum loci to assess the significance of the difference.

5. To consider the recommendation of a new TC to carry out further study.

Reporter: Michael Brill US

As the reporter for R1-51 Maxwell versus Maximum Saturation Colour Matches, I regret to report that there has been no progress this year, except to note a relevant manuscript: "Quantal and non-quantal color matches: Failure of Grassmann's laws at short wavelengths," by Joel Pokorny, Vivianne C. Smith, and Jun Xu, to appear in J. Opt. Soc. Am. A.

R-54 (V) Variability in Colour-Matching Functions

Established: 2011

Terms of To document available data that describe the variation in colour matching

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Reference: functions, together with an analysis of their variability.

Reporter: Abhijit Sarkar IN

The report is going to be based principally on this reporter’s doctoral thesis work at Technicolor Research & Innovation in Rennes, France, conducted under the supervision of the University of Nantes, France. The goal of this work, officially completed in November 2011, was to provide a practical solution to the issue of observer metamerism in industrial applications involving large-field color-matching. As part of this work, a comprehensive theoretical analysis was conducted on various aspects of the physiologically-based observer model (CIEPO06) proposed by CIE TC 1-36. In the context of color perception on modern narrow-band displays, the performances of the CIEPO06 model and of the CIE 10° standard colorimetric observer in predicting average Stiles and Burch (1959) observer data were evaluated. Some weaknesses of both observer models were identified, and an improvement of the CIEPO06 model was proposed based on a nonlinear optimization.

In modeling observer variability, this work took a different approach compared to the previous attempts at establishing a standard deviate observer. A major contribution of this work has been to prove through visual experiments, the hypothesis that color-normal human observers can be classified into a small number of categories based on their color vision. A set of eight colorimetric observer categories was proposed for use in color and vision sciences. These categories, each characterized by a set of color-matching functions, were derived through statistical analyses performed on existing experimental and physiological color-matching data. This was followed by the development of a compact, inexpensive proof-of-concept prototype, the Observer Calibrator. The prototype instrument is capable of determining, from a given set of observer categories, the most suitable category for any color-normal observer. Using this prototype, two collaborative observer classification experiments were performed with researchers in Germany and Hungary, involving a total of 49 observers. Results clearly demonstrated the age-dependence of such classification, revealed some interesting trends, and provided an indirect validation of the observer classification method. An implementation of colorimetric observer categories in a practical color imaging work- flow has been proposed in the thesis, but this necessitates the standardization of the categories and also of the observer classification method.

During the past year, several prominent CIE members have been involved in evaluating this work in various capacities, most notably Prof. Françoise Viénot, Prof. Mark Fairchild, Prof. Sabine Süsstrunk and Prof. János Schanda. Technicolor R&I and the Munsell Color Science Lab at RIT have just started discussing the possibility of working together to take the work forward, and this reporter has volunteered to be involved in such collaborative research. It seems critical that the CIE monitors and streamlines future research and development efforts in this area. The R1-54 report would hopefully set the necessary groundwork.

The R1-54 report, currently under preparation, is going to propose the establishment of a Technical Committee to revisit the aspects of the variability in color-matching functions. With regard to large- field color-matching, the possibility of establishing a suitable number of colorimetric observer categories, characterized by specific color-matching functions, needs to be investigated. It will be further proposed that this Technical Committee work toward standardizing the observer classification method, so that it can be made available to the color and vision sciences community. As far as the variability in small-field color-matching functions is concerned, various domain experts within the CIE will be consulted on whether and how to include such discussions in the R1-54 report. The report is planned for submission well before the one-year deadline of July 2012.

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R-57 (V) Border Between Luminous and Blackish Colours

Established: 2011

Terms of Reference:

Study the literature which determines by psycho-physical and physiological experiments the colour border between luminous and blackish colours in white surrounds.

Reporter: Thorstein Seim NO

No report.

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COLOUR SECTION: TECHNICAL COMMITTEES

TC1-55 (C) Uniform Colour Space for Industrial Colour Difference Evaluation

Established: 1999

Terms of

Reference:

To devise a new uniform color space for industrial color-difference

evaluation using existing experimental data.

Chairman: M Melgosa ES

Members: Members: D Alman US, R Berns US, E Carter US, G Cui GB,

M D Fairchild US, R Kuehni US, M R Luo GB, J Nobbs GB, C Oleari IT,

M R Pointer GB, D Rich US, K Richter DE, B Rigg (GB), A R Robertson CA,

J Romero ES, G Rösler DE, M Vik CZ, K Witt DE, J H Xin CN, and

H Yaguchi JP

Advisor: R Huertas ES

During 2011 members of this TC have developed specific datasets (e.g. S.G. Lee, R. Shamey, D. Hinks, W. Jasper, Color Res. Appl. 36, 27-41, 2011) confirming the good performance of the CIEDE2000 color-difference formula with respect to previous formulas. The influence of the uncertainty associated with visual data on the performance of different color-difference formulas has also addressed (e.g. S. Shen, R.S. Berns, Color Res. Appl. 36, 15-26, 2011). The usefulness of the STRESS index to evaluate intra- and inter-observer variability has been discussed (M. Melgosa, P.A. García, L. Gómez-Robledo, R. Shamey, D. Hinks, G. Cui, R. Luo, J. Opt. Soc Am. A 28, 949-953, 2011), and some potential limitations of the STRESS index have been reported (E. Kirchner, N. Dekker, J. Opt. Soc. Am. A 28, 1841-1848, 2011).

A general color-difference formula for any illuminant and observer that assumes perfect color constancy in a color-vision model based on the OSA-UCS system (C. Oleari, M. Melgosa, R. Huertas, J. Opt. Soc. Am. A 28, 2226-2234, 2011) has been proposed. Informal discussions among members of this TC since the last interim meeting of the AIC (AIC 2011, Zurich, June 2011) revealed a common feeling that there are different color-difference formulas with associated color spaces (e.g. DIN99d, CAM02-UCS, Berns-IPT based models, OSA-GP-Euclidean, etc.) which perform similarly to CIEDE2000. However, in the near future it seems difficult to achieve agreement on just one color space with an associated color-difference formula that is significantly better than CIEDE2000, for a wide set of reliable experimental datasets.

TC1-57 (C) Standards in Colorimetry

Established: 2000

Terms of Reference:

To prepare a series of CIE/ISO/IEC Standards that describe:

1. The method of calculating CIE tristimulus values and chromaticity co-ordinates

2. A uniform colour space and its associated metrics

3. A formula for industrial colour difference evaluation

Chairman: AR Robertson CA

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Members: P Alessi US, M Brill US, JA Bristow SE, J Campos Acosta ES, R Connelly US,

JF Decarreau FR, R Harold US, R Hirschler HU, H Ikeda JP, B Jordan CA, C Kim KR,

D McDowell US, P McGinley AU, Y Ohno US, MR Pointer UK, K Richter DE,

G Roesler DE, JD Schanda HU, R Sève FR, K Witt DE, H Yaguchi JP, J Zwinkels CA

Liaisons IEC TC100/TA2, H Ikeda; ISO TC 6, B Jordan; ISO TC35/SC9/WG22, G Roesler;

ISO TC38/SC1/WG7(UK), M Pointer; ISO TC38/SC1/WG7(US), R Harold;

ISO TC42, D. McDowell; ISO TC130, D. McDowell; ISO/IEC/JTC1/SC28, K Richter

TC 1-57 is responsible for the preparation of four CIE Standards: S 014-3 Colorimetry – Part 3: Calculation of CIE tristimulus values S 014-4 Colorimetry – Part 4: CIE 1976 L*a*b* colour space S 014-5 Colorimetry – Part 5: CIE 1976 L*u*v* colour space and u', v' uniform chromaticity scale diagram S 014-6 Colorimetry – Part 6: CIEDE2000 colour-difference formula

Part 4 (CIE 1976 L*a*b* colour space) has been approved and was published in September 2007 as CIE Standard S 014-4/E:2007. In addition, it has been approved by ISO and published as ISO 11664-4:2008(E).

Part 5 (CIE 1976 L*u*v* colour space and u', v' uniform chromaticity scale diagram) has been approved and was published in March 2009 as CIE Standard S 014-5/E:2009. It has been approved by ISO and published as ISO 11664-5:2009(E).

Part 3 (Calculation of CIE tristimulus values) has been approved and was published in July 2011 as CIE Standard S 014-3/E:2011. It has been accepted by the ISO production services and submitted for a five-month FDIS vote in accordance with the Fast-track procedure.

Part 6 (CIEDE2000 colour-difference formula) is based on CIE Publication 142-2001. It uses Sharma’s algorithm for computing h'bar and includes an “informative annex” on Nobbs’ method for lightness, chroma and hue splitting. It was approved by an internal vote of TC 1-57 in July 2011. In accordance with the new CIE procedure, the CB then prepared a Committee Draft (CD 014-6) which was approved by the TC in December 2011. Following that, the CB prepared an Enquiry Draft (ED 014-6) and submitted it to the BA and D1 for comments with a deadline of 6 February 2012.

TC1-61 (C) Categorical Colour Identification

Established: 2001

Terms of Reference:

To prepare a report describing a color categorization map for the photopic and mesopic illumination levels.

Chairman: T Ishida JP

Members: N Johnson US, K Okajima JP, M Pointer UK, L Ronchi IT, K Sagawa JP, J Schanda HU,

H Shinoda JP, O Da Pos IT, MR Luo UK, H Yaguchi JP, F Viénot FR(observer)

The 2nd draft report was written and circulated to the committee members in October 2011. Some members made critical comments mainly on the lack of data from different studies to be included in the TC report. The chair is seeking an acceptable way to prepare the final draft report based on these inputs from the TC members.

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TC1-63 (C) Validity of the Range of CIEDE2000

Established: 2001

Terms of Reference:

Terms of To investigate the application of the CIEDE2000 equation at threshold, and to CIELAB colour differences greater than 5 units.

Chairman: K Richter DE

Members: P. Alessi US, K.R. Gegenfurtner DE, T. Holtsmark NO, M.R. Luo GB, M. Melgosa ES,

Y. Nakano JP, J. Nobbs GB, C. Oleari IT, D. Rich US, J. Schanda HU, T. Seim NI,

M.Vik CZ, P. Walraven NL, H. Yaguchi JP

A first CIE draft of a proposed Technical Report of TC1-63 with the following content is under way: 1. Terms of reference 2. Test charts and CIELAB data for the study of large colour differences 3. Results from different countries (CZ, DE, ES, GB) 4. Standard deviation and correlation in terms of stress values 5. Results for small colour differences (Kittelmann, Witt, Melgosa, Luo) 6. Standard deviation and correlation in terms of stress values 7. Discussion of the results 8. Summary 9. References

Workplan (timeframe): First draft of a Technical report (Chairman and Members): June 2012 Second draft which includes Comments of Committee Members: September 2012 Draft for voting by Committee Members of TC1-63: January 2013 Draft for voting by CIE Division 1: April 2013 Publication: 2013

TC1-64 (C) Terminology for Vision, Colour and Appearance

Established: 2003

Terms of Reference:

To monitor the terminology requirements of Division 1 including the revision of the present ILV terms and the addition of new terms.

Chairman: S. McFadden CA

Members: P Bodrogi HU, EC Carter US, O da Pos IT, J Gardner, AU, Y Nakano JP,

MR Pointer GB, M Melgosa ES

No report.

TC1-68 (C) Effect of Stimulus Size on Colour Appearance

Established: 2005

Terms of Reference:

To compare the appearance of small (<2) and large(>20) uniform stimuli on a neutral background.

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Chairman: P. Bodrogi HU

Members: P Alessi US, KF Anter SE, EC Carter US, I-P Chen TW, O da Pos IT, CS Kim KR,

G Kutas HU, MR Luo GB, M Nicholson GB, T Nilsson CA, K Sagawa JP,

J Schanda HU, R Ûnver TR, F Viénot FR, K Xiao KR

Advisor: G. Derefeldt SE

The Technical Report is ready. The English, French and German abstracts are now being written.

TC1-69 (C) Colour Rendition by White Light Sources

Established: 2006

Terms of Reference:

To investigate new methods for assessing the color rendition properties of white-light sources used for illumination, including solid-state light sources, with the goal of recommending new assessment procedures.

Chairman: Wendy Davis US

Members: Richard Young US, Ronnier Luo GB, Changsoon Kim KR, Peter Bodrogi HU,

Danny Rich US, Yoshi Ohno US, Ferenc Szabó HU, János Schanda HU,

Emil Radkov US, Hirohisa Yaguchi JP, Peter van der Burgt NL, Boris Shugaev RU,

Kenjiro Hashimoto JP, Robert Hirschler HU, Danielle Ferreira de Oliveira BR,

Ian Ashdown CA, Osvaldo da Pos IT, Cheng Li GB, Andrew Jackson US,

Günther Heidel DE, Ronald Daubach US, Ulrich Binder DE, Werner Jordan DE,

Rolf Bergman US, Peter Hanselaer BE, Klaus Richter DE, Maria Thompson US,

Sophie Boissard FR, Françoise Viénot FR, Katalin Toth HU, Kevin Smet BE,

Nicolas Pousser FR, Tadashi Yano JP, Andreas Kraushaar DE, Takayoshi Fuchida JP,

Kevin Dowling US, Lorne Whitehead CA, Jean Paul Fressinier US, Mark Rea US

The first several months of 2011 were quite inactive, though a few research reports were submitted to the TC. In 2010, 60% of the members voted to allow more time for new ideas. As a result, two additional metric proposals were introduced to the TC late in 2010. This additional time was not fruitful.

This TC met at the CIE session in Sun City, South Africa in July of 2011. This meeting included presentations from nine TC members on what they believed the TC should recommend in its technical report.

Opinions on the committee remained divided over support for recommending the Color Quality Scale (CQS) and support for recommending a fidelity-only metric of colour rendering. As in 2010, it was suggested that two metrics be recommended, making explicit their different purposes. After some negotiating, including recommending the two metrics in separate TC reports, this plan was agreed upon, pending agreement from TC members unable to attend the meeting. Following the meeting, a small group of TC members disagreed about what was concluded at the meeting. This disagreement remains unresolved.

More disagreements arose over e-mail following the TC meeting, both by members who did and did

16

not attend the meeting. Though some of these issues are working toward compromise, they remain unresolved.

Soon before our annual meeting, an updated version of CRI-CAM02UCS, now called the nCRI, was introduced to the TC. It yielded results that were unacceptable to several members of the TC, so an amended version was presented at the TC meeting. Though its outputs appeared acceptable, some of the members objected to its reflective samples. It was agreed that a sub-group of interested TC members would work together to revise the nCRI. A new version of the nCRI was distributed to the TC on the 30th of December, 2011. It has not yet been evaluated.

TC1-70 (C) Metameric Samples for Indoor Daylight Evaluation

Established: 2007

Terms of Reference:

To investigate the derivation of a set of metameric samples to enable the evaluation of indoor daylight simulators

Chairman: B Kránicz HU

Members: Péter Bodrogi DE, Robert Hirschler HU, Danny Rich US, Alexander Rosemann CA, János Schanda HU

During the past two years, based on the work ISO - CIE: Standard method of assessing the spectral quality of daylight simulators for visual appraisal and measurement of colour, ISO 23603:2005 (E) - CIE S 012/E:2004, five metameric samples were derived for ID65 and ID50 for the evaluation of indoor daylight simulators in the visible range. For the UV range three samples were determined. For both ID65 and ID50 in the VIS and UV ranges Excel spreadsheets were prepared to ensure a convenient way to evaluate indoor daylight simulators. A draft paper was assembled. In the summer of 2011 Ellen Carter sent me the official forms to be filled in and to be circulated among the TC members.

Next working step: circulation of the draft and completion of the work. This is intended to be done in 2012.

TC1-71 (C) Tristimulus Integration

Established: 2007

Terms of Reference:

To investigate methods for computing weighting tables for the calculation of tristimulus values from abridged data.

Chairman: C Li CN

Members: J Campos Acosta ES, M Brill US, H Fairman US, B Jordan CA, Y Ohno US, C Oleari IT,

MR Pointer UK, AR Robertson CA, G Roessler DE, J Schanda HU, R Seve FR,

G Wang CN

In the past year, there was not much work produced by this TC. Changjun Li, Claudio Oleari, members of this TC, together with Manuel Melgosa (Spain) and Yang Xu (China), re-studied the Oleari method for computing the tristimulus values and gave two methods for computing weighting tables for calculating the CIE tristimulus values based on the work of Oleari. The work was published in JOSA A [Changjun Li, Claudio Oleari, Manuel Melgosa, and Yang Xu, Methods for computing weighting tables based on local power expansion for tristimulus values computations, Journal of

17

Optical Society of America. A, Vol. 28, No. 11 (November 2011), pages 2243-2252.]. This work will make the comprehensive comparison of methods selected by the TC much easier.

CIE and Division 1 had a meeting in Sun City in South Africa in July and allowed TC1-71 to continue for another year to complete its work.

To complete the TC work in 2012, it is expected that the comprehensive compression will be made in the first 6 months in the year and a second draft Technical Report will be completed and ready for discussion among members in August; a final Technical Report should by the end of 2012.

TC1-73 (C) Real Colour Gamuts

Established: 2007

Terms of Reference:

To recommend a gamut representative of real (non-fluorescent) surface colours and defined by associated spectral reflectance data.

Chairman: C Li CN

Members: P Alessi US, Maeng-Sub Cho, MR Luo GB, F Martinez-Verdu ES, Jan Morovic,

M R Pointer GB, Jin-Seo Kim KR, K Richter DE, Krisztián Samu HU, Pei-Li Sun TW

Observers: Ellen C Carter US, Siu-Kei Tin

During the past year not much work has been done by this TC due to the relocation of the TC chair. CIE and Division 1 had a meeting in Sun City in South Africa in July and was given a two-year extension was given for the work of this TC. Thus, the TC has to complete its work by the end of 2013.

In order to fit into this 2 year period, the time scale is planned as follows. From January to August, 2012, it is aimed to develop a gamut specified in terms of CIELAB coordinates under D50 and the CIE 1931 standard observer. From September 2012 to April 2013, the gamut in terms of reflectance spectra should be developed. From May 2013, a draft technical report should be considered and this should be ready by July 2013 for discussions among TC members. The final technical report should be completed by the end of 2013.

TC1-74 (C) Methods for Re-defining CIE D Illuminants

Established: 2009

Terms of Reference:

To investigate the issue of smoothing the values of the D illuminants such as described in CIE 15:2004 Appendix C and to propose the calculation methods for new definitions of the D Illuminants.

Chairman: Janos Schanda HU

Members: Hugh Fairman US, Robert Hirschler HU, Balázs Kránicz HU, Changjun Li CN,

Yoshi Ohno US, Danny Rich US

The TC 1-74 draft will go out to the TC members by end of February 2012. The viewpoint of the TC is rather divided as to whether we should recommend the Sprague interpolated curves or the super-smoothed ones.

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The chair has modified the text so that TC can vote, but some explanations are still missing and work is continuing on it.

TC1-75 (C) A Comprehensive Model of Colour Appearance

Established: 2009

Terms of Reference:

To derive colour appearance models that include prediction of the appearance of coloured stimuli viewed in typical laboratory conditions that 1) appear as unrelated colours, 2) are viewed under illumination down to scotopic levels and 3) include consideration of varying size of stimulus.

Chairman: Ronnier Luo UK

Members: R. W. G. Hunt GB, M. Fairchild US, N. Morony US, C. Y. Fu CN, C. Li CN,

K. D. Xiao CN, Y. S. Kwak SK, S. Y. Choi SK, H. Yaguchi JP

A paper was accepted for publication by Color Research and Application [1] dealing with unrelated colours under photopic and scotopic vision. Also, a book chapter by Luo and Li [2]. was written, which describes the extension of CIECAM02 to predict the two effects investigated in this TC.

The reverse model is also under development. The Collaboration tool notification will be carried out this year.

Reference 1. C. Y. Fu, M. R. Luo, C. J. Li, G. H. Cui, R. W. G. Hunt and M. R. Pointer, An investigation of colour

appearance for unrelated colours under photopic and mesopic vision, Color Res. Appl., 36(2011)in press.

2. M. R. Luo and C. J. Li, Chapter 3. CIECAM02 and its recent developments, C. Fernandez (Eds), Advanced color image processing and analysis, Springer, 261-294 2012, in press.

TC1-76 (C) Unique Hue Data

Established: 2009

Terms of Reference:

To study and report on unique hue data, including an analysis of the scatter of those data: this to include practical viewing conditions.

Chairman: Sophie Wuerger GB

Members: Miyoshi Ayama JP, Rolf Kuehni US, Katsurnori Okajima JP, Galina Paramei GB,

Renzo Shamey US, Vicki Volbrecht US, Michael Webster US, Kaida Xiao GB

The draft report has been completed.

TC1-77 (C) Improvement of the CIE Whiteness and Tint Equations

Established: 2009

Terms of Reference:

To recommend improvements or modifications to the existing CIE Equations for Whiteness and Tint to extend their scope of application to a wider range of instrument conditions and white materials; e.g. various tints and levels of

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fluorescence.

Chairman: Robert Hirschler HU

Members: M Ayama JP, M Brill US, E Carter US, D Chen CN, R Connelly US, D Fleming US,

P Green GB, P Hubner DE, K Imura JP, B Jordan CA, R Luo GB, D Oliveira BR,

C Puebla DE, D Rich US, P Robertson US, W Schlenker DE, R Sève FR,

T Shakespeare FI, C Silva BR, A Springsteen US, K Wobser DE, D Wyble US, Z Xu CN,

J Zwinkels CA

Advisors: S H Amirshahi IR, R Harold US, S Rydefalk SE

The CIE Central Bureau has approved the establishment of this TC that was proposed at the 2009 meeting of CIE Division 1 in Budapest, Hungary. The following working program has been accepted by the TC:

1. Preparation of textile, paper or other sample sets Prepare textile, paper or other sample sets to be used in visual and instrumental evaluation of whiteness. The sample sets should sufficiently cover the whole area considered “white” by the current CIE limits and should also include samples which are visually considered “white” but fall outside the current limits.

2. Experimental work on measurement geometry

Develop a correction method for the transfer of calibration data obtained on 45:0 instruments in

National Standardizing Laboratories to industrial instruments using d:0 or d:8 geometry.

3. Visual/instrumental evaluation under different light sources Verify the validity of the current whiteness formula under different light sources (D65 / D50 / ID65 / ID 50 / A / TL84 / other). Recommend the necessary modification(s) in order to achieve sufficiently high correlation between visual and instrumental results under each of the illuminants/sources.

4. Practical calibration of spectrophotometers. Verify the suitability of the Ganz-Griesser calibration method and formula for the “absolute” (instrument-independent) specification of whiteness: in case of positive results recommend to develop it into a CIE standard.

5. Extension of the CIE whiteness limits The CIE whiteness formula establishes tint and whiteness limits; many commercial papers and possibly also textiles perceived as white, fall outside these. Modify the CIE whiteness formula (e.g. by the introduction of a penalty function) to handle white materials at the vicinity of the upper CIE whiteness limit and also verify experimentally the tint limits modified in 2004.

6. Prepare a CIE Technical Report on the findings and make recommendations as described under items 2 to 5.

No feedback has been received until now on any experimental work by TC members.

TC1-81 (C) Validity of Formulae for Predicting Small Colour Differences

Established: 2010

Terms of Reference:

1. To evaluate available formulae for small colour differences (<~2.0 CIELAB).

2. To define a visual threshold colour difference.

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Chairman: Klaus Richter DE

Members: S Bracko SI, MR Luo GB, M Melgosa ES, G Roesler DE, T Seim NO

Background information The results of different countries which contribute to CIE TC1-63 show problems of the formula CIE DE2000 to describe threshold data, compare (5 slides, 90 KB) http://130.149.60.45/ ~farbmetrik/CIE_1_63_ARP11.PDF.

The above terms of reference of TC1-81 to evaluate small (near-threshold) colour difference need a colour metric which is different from CIE DE2000 and/or CIELAB. Some differences of a colour metric for larger colour differences (>10 CIELAB) and for thresholds were presented at the CIE Division 1 meeting in Sun City, see (9 slides, 140 KB) http://130.149.60.45/~farbmetrik/CIE_1_81_ARP11.PDF.

An appropriate solution to describe many experimental data by a colorimetric model seems possible now. The physiological signals for different colours as a function of relative luminance in a grey or white background seem to be one key, see Fig. 1 which shows the relative luminance Lr of, for example Blue B. This luminance is only 9% compared to the luminance of White W (90% reflection). The relative luminance Lr decreases from high to low values for the colours White W (90%), Yellow Y (81%), Green G (70%), Red R (20%), and Blue B (9%). The values are only rough values to be determined.

In Fig. 1, the S-shaped curve for Blue B has the largest slope for the relative luminance 9% compared to the white surround (90%). However there are many blues of different chromaticity. The chromaticity of Blue B is determined by the most chromatic optimal colour of "have the spectrum" with the two complementary wavelength limits 503c nm and 503 nm (503 nm is approximately elementary green).

Similar the chromaticity of Yellow Y (81%) is determined by the complementary colour to Blue B

(9%). Both add to White W (90%). This is similar for the complementary optimal colours Green G (70%) and Red R (20%) which have both the complementary wavelength limits of about 475nm and 574nm.

According to a book of A. Valberg (2005) physiology shows both increment (I) and decrement (D) signals for Yellow and "White minus Yellow" as function of relative luminance Lr, and similar for Blue and "White minus Blue". It may be similar for the above Green G (70%) and Red R (20%).

If we use the letter N (french Noir) for Black, then the two hue triangles with the corners N, Y or B, and W show darker colour series between N and Y or B, and lighter colours between W and Y or B. In Fig. 1 the darker colour series are described by the increment (I) signals. Similar the lighter colour series can be described by the decrement (D) signals (for example the "White signal" minus the "increment (I) signal"). The decrement signals are not shown in Fig. 1, see examples and many experimental threshold data in a book of K. Richter (1996).

The symmetry of the signal slopes of incremental (I) and decremental (D) signals creates equal

21

chromatic threshold data for complementary optimal colours. Valberg and Holtsmark (1971) have published the corresponding experimental results. The following linear model is based on CIE colour matching functions. The metric is in agreement with the above results see (18 slides, 470 KB) http://130.149.60.45/~farbmetrik/CIE_TC1-63M_10.PDF.

In Fig. 1 the Grey Cero Colours (G0-Colours) of a book of R. Evans (1974) may correspond approximately to the colours on the yellow horizontal line (9% to 90%). According to Evans the chromatic threshold is by a constant factor (here 22) lower compared to this yellow line. This chromatic threshold is indicated by the red line (0,4% to 4%). Evans reported that the Blue luminance (here Lr = 0,4%) at threshold is below the achromatic luminance at threshold (here Lr = 4%) in agreement with Fig. 1.

According to a decision of the CIE Division 1 meeting in 2011 a new Reportership CIE R1-57 by T. Seim (Norway) will study the "Border between Luminous and Blackish Colours". This border may be near the Evans G0-colours. The results of CIE R1-57 are of high interest for TC1-81 because of the possible relation to threshold data. For some background information which has been produced for the CIE decision, see (10 slides, 200 KB) http://130.149.60.45/~farbmetrik/CIE1_RS_11.PDF.

The following experimental threshold data and physiological models are main sources for a draft Report of TC1-81:

1. The book "Perception of Colour" by R. M. Evans (1974), Wiley 2. The Ph. D. thesis of P. Kittelmann (2010), see (132 pages, 9,8 MB),

http://opus.kobv.de/tuberlin/volltexte/2010/2634/ 3. The book "Computergrafik and Colorimetry (in German)" by K. Richter (1996), VDE-Verlag, see

(288 pages, 2,6 Mbyte) http://130.149.60.45/~farbmetrik/BUA4BF.PDF 4. Valberg, A. and Holtsmark, T. (1971), Similarity between JND-curves for complementary optimal

colours, In: Color Metrics, AIC, Soesterberg, TNO, 58-68 5. Valberg, A. (2005), Light Vision Color, Wiley, 462 pages

Workplan (Timeframe): Study and analysis of more colorimetric and physiological models and experimental data at threshold (Chairman and members): September 2012 First draft of a Technical Report (Chairman and Members): April 2013 Second draft which includes Comments of Committee Members: September 2013 Draft for voting by Committee Members of TC1-81: January 2014 Draft for voting by CIE Division 1: April 2014 Publication: 2014

TC1-85 (C) Update CIE Publication 15:2004 Colorimetry

Established: 2011

Terms of Reference:

To update CIE Publication 15:2004 taking into consideration the current

CIE/ISO standards on colorimetry and the work of TC1-36 Fundamental

Chromaticity Diagram with Physiologically Significant Axes

Chairman: Janos Schanda HU

Members: Francoise Viénot FR, Alan Robertson CA, Mike Pointer GB, Hirohisa Yaguchi GB,

Ellen Carter US

No report.

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TC1-86 (C) Models of Colour Emotion and Harmony

Established: 2011

Terms of Reference:

To recommend models of colour emotion and harmony based on existing psychophysical data obtained by different research groups or networks for applications in the colour design area.

Chairman: Li-Chen Ou TW

Members: M. Ronnier Luo GB, Mike Pointer GB, Osvaldo Da Pos IT, Tetsuya Sato JP,

Shing-Sheng Guan TW, Suchitra Sueeprasan TH, Rafael Huertas ES,

Ferenc Szabó HU, John Hutchings GB, Tien-Rein Lee TW, Wen-Yuan Lee TW

Established during the 27th CIE Session in July, 2011, the TC has now confirmed members from 7 countries including Taiwan, UK, Italy, Japan, Spain, Thailand and Hungary.

The members have agreed a four-year work programme, as shown below:

2011

Oct – Dec Confirmation of the members list and a work programme for the TC

TC Membership Application Form and Copyright Agreement to be signed and returned to TC chair (TCC).

A work programme to be agreed amongst the members. 2012

Jan – Jun Literature survey of colour emotion and harmony

Scope of research within the TC, including the definition of colour emotion and harmony, together with the approach to studying the subject area, will be determined on the basis of the survey and agreed amongst TC members.

Jan – Sep Collecting and sharing existing experimental data of colour emotion and colour harmony

Experimental data in the form of Excel files, together with descriptions of methods of data collection, will be sent to the CIE Collaboration Tools and shared by all TC members.

Oct – Dec Assignment of new colour emotion/harmony scales to TC members for developing new models

A list of colour emotion/harmony scales to be studied in this project will be agreed amongst all TC members.

Each TC member can choose to become model developers of some of the new scales, or they can choose to become reviewers of the new models. If any scale is picked by more than one TC members for model development, these scales will be reviewed and compared at a later stage.

2013

Jan – Jun Model developing

New models (draft) in the form of a short report describing methods of modelling will be reviewed by all TC members via the Collaboration Tools.

Jul – Sep Reviewing and comparisons of new models

A short review report made by each TC member should be submitted to the Collaboration Tools. In addition to any issues identified, the report should also recommend one model for each scale if there are more than one models developed for one scale.

Oct – Dec Refinement of new models

Refined models in the form of a short report describing how issues have been

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addressed will be reviewed by all TC members via the Collaboration Tools. 2014

Jan – Mar Final refinement

Any further issues must be addressed before agreement can be reached amongst all TC members.

Apr – Sep First draft of TC report

Oct – Dec Second draft of TC report

2015

Jan – Mar Final version of TC report

TC1-87 (C) New Aspects of Colour Rendering

Established: 2011

Terms of Reference:

To investigate available methods for assessing the colour rendering capabilities of all types of white light source with a view to possibly recommending a new assessment index or indices.

Chairman: Mike Pointer GB

Members:

This Committee will commence its work when a final decision has been made as to the contents of the Technical Report(s) to be produced by TC1-69 Colour Rendition by White Light Sources. Contact has been established with a number of potential members who represent work published on new aspects of colour rendering including methods based on colour memory, colour categories, colour harmony, visual clarity, as well as enhancements of the traditional CIE type of colour rendering index.

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COLOUR SECTION: REPORTERS

R1-42 (C) Extension of CIECAM02

Established: 2007

Terms of Reference:

To evaluate potential additions to CIECAM02 in liaison with Division 8 and to include:

Those published in the literature;

Extension to include unrelated colours;

Extension of the range down to scotopic levels

Reporter: Changjun Li CN

CIE and Division 8 had a meeting in Sun City in South Africa in July and gave the TC8-11 a further 4 year extension.

Recently, Li, Luo and Wang [1] have tested CIECAM02 with various CAT02 matrices using the corresponding and colour appearance data sets. In particular, Li, Luo and Sun [2] have considered the CIECAM02 equation with the HPE matrix and discussed how the model can be simplified and how the model performed on the corresponding and colour appearance data sets.

[1] Changjun Li, M Ronnier Luo and Zhifeng Wang, Different matrices for CIECAM02, submitted to Colour Research and Application.

[2] Changjun Li, M Ronnier Luo and Pei-Li Sun, A new version of the CIECAM02 with the HPE matrix, submitted to CGIV 2012.

R1-50 (C) 3D Aspects of Visual Appearance Measurement

Established: 2009

Terms of Reference:

1. To review the activity of relevant organisations related to 3D vision, 3D image capture, 3D model storage and 3D display where these are relevant to visual appearance issues

2. To establish a database of key research articles, technology and terminology related to 3D aspects of visual appearance

3. To establish an international panel of experts able and willing to advise on 3D matters

4. To liaise with other CIE divisions

Reporter: David Simmons GB

No report.

R1-52 (C) Spectral Data Interpolation

Established: 2010

Terms of To review the methods, and make a recommendation for the interpolation of

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Reference: existing, highly structured source spectra, including the FL illuminants, for colorimetric calculations.

Reporter: Hugh Fairman US

No report.

R1-53 (C) Gloss Perception and Measurement

Established: 2011

Terms of Reference:

1. To establish a database of key research articles and terminology related to gloss perception and to gloss measurement.

2. To investigate if, from this database, improved measurement methods could be suggested in order to achieve a better correlation between gloss perception and measurement.

Reporter: Frédéric Leloup BE

Although additional measurement methods have been introduced, instrumental gloss evaluation is usually restricted to the measurement of the specular reflection by use of a specular glossmeter. Several investigations demonstrated that the correlation between visual gloss appraisal and specular glossmeter readings is rather poor. This is not surprising, given the fact that the specular glossmeter only reports on one specific attribute of gloss perception. In the last 15 years, more sophisticated instruments have been introduced and reported. These instruments make it possible to describe the directionally selective reflectance properties of the front surface by means of the bidirectional reflectance distribution function (BRDF).

With the strong progress made in computer graphics and digital imagery applications, the understanding of how human observers evaluate and interpret surface gloss has also received increased attention from both computer graphics and vision scientists. The influence of other optical and geometrical object attributes (colour, texture, 3D shape, etc.), as well as the influence of the geometry of illumination on gloss perception have been examined. To elucidate how the visual system utilizes information from images to infer surface appearance properties, vision scientists have investigated if simple image statistics could be characteristic of surface reflectance properties. All key research articles are currently gathered into a database. Additionally, a new study has been set up with real stimuli that are different regarding multiple visual gloss criteria. It will be investigated if, from the database and the current investigations, improved measurement methods could be suggested in order to achieve a better correlation between gloss perception and measurement.

R1-55 (C) Enhancement of Images for Colour Defective Observers

Established: 2011

Terms of Reference:

To review the literature for enhancing images to improve their quality for

colour defective observers.

Reporter: Po-Chieh Hung JP

Current progress (as of Dec. 16):

Collecting literature by two categories: non-patent and patent.

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(1) non-patent (academic paper, book and web page): collected 47 items. (2) patent: collected 28 patents.

Future plan:

Collect literature by the end of January, 2012

Filter and categorize them by the contents by the end of March, 2012

Write up the report by the end of May, 2012.

R1-56 (C) Skin Colour Database

Established: 2011

Terms of Reference:

1. To assemble a database of skin colours, to include spectral data and measurement method.

2. To report on the variation in colour between different ethnic groups, genders and body parts.

Reporter: Kaida Xiao CN

Skin Colour Data in the University of Sheffield

Ethics approval had been obtained from the University of Sheffield UREC to carry out the skin colour measurement and analysis on volunteers. A Minolta CM 2600d spectrophotometer using SpectraMagic NX Colour Data Software was used to take colour measurements of both CIE XYZ tristimulus values in 2 degree standard observer with the unit of cd/m2 and spectral reflectance data with a wavelength range of 360 nm to 740 nm with a 10 nm interval. The illuminant was set to the CIE standard D65. A direct skin colour measurement was conducted for each subject for a total of nine body areas - forehead, tip of nose, cheek, ear lobe, chin, back of hand, palm, outer forearm and inner forearm using the spectrophotometer.

The skin colour measurements were conducted in UK, China and Iraq. To date, we accumulated the skin colours in 424 subjects and the data is recorded in spectral reflectance.

Table 1. Skin colour data in different Ethnic Groups

Caucasians Chinese Middle-East Asian African

Ethnic Group 53 202 161 6 2

The measurements will be conducted in both UK and India in 2012. The skin colour data measured by other institutes will be obtained and compared with the data obtained in University of Sheffield.

Skin Colour Variations

Skin colour appearances are predicted by transforming CIEXYZ tristimulus values to colour appearance attributes using CIECAM02 colour appearance model. The skin colours were plotted in CIECAM02 colour space for Caucasians and Chinese in Figures 1 and 2, respectively. The skin colour variations between different Caucasians and Chinese were investigated. The skin colour variations between facial and arm colour were also analysed.

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(a) Top view (b) Side view

Fig. 1. Skin Colour Gamut for Caucasians

Fig. 2. Skin Colour Gamut for Chinese Table 2. Skin Colour ranges of Caucasians

CIECAM02 Lightness Chroma Hue

Min 39.5 8.3 20.5

Max 62.9 32.4 68.7

Table 3. Skin Colour ranges of Chinese

CIECAM02 Lightness Chroma Hue

Min 37.1 8.3 31.3

Max 61.5 22.5 78.0

To investigate the skin colour variations between Caucasians and Chinese, Figure 3 was plotted. It was found that Skin colour of Caucasians is lighter, more colourful and more reddish than skin colour of Chinese. The Facial colour is more colourful and more reddish comparing with Arm colours for both Caucasians and Chinese.

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Fig. 3. Skin colour variations between Caucasians and Chinese

0

10

20

30

40

50

60

70

80

Facial Arm Facial Arm Facial Arm

Caucasians

Chinese

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LIAISONS

L1-1 Association International de la Couleur

Liaison: Paula J Alessi US

No report.

L1-2 CCPR (Comite Consultatif de Photometrie et Radiometrie), BIPM

Liaison: M Stock FR

The CCPR meets about every two years at the BIPM in Sèvres, France, bringing together experts from its member NMIs (National Metrology Institutes). The last meeting of the CCPR took place from 17-18 September 2009. The CCPR working groups met in September 2011 during the NewRad conference. The next meeting of the CCPR will take place in February 2012. General information on the work of the CCPR can be found on www.bipm.org/en/committees/cc/ccpr.

The key comparison working group has set up a schedule for the second round of key comparisons, which are the technical basis for the CIPM Arrangement on Mutual Recognition of National Measurement Standards and of Calibration and Measurement Certificates issued by National Measurement Institutes. The key comparisons demonstrate the technical capabilities of the participating NMIs. The first comparisons to be repeated are for regular spectral transmittance (start in 2011), for luminous intensity and luminous flux (start in 2012) and for spectral responsivity in the visible and infrared regions (start 2013). The results of the completed key comparisons of the first round can be found in the key comparison data base, held at the BIPM (kcdb.bipm.org/appendixB).

The members of the task group on the SI of the Strategic Planning Working Group have published a position paper on “Photometry, radiometry and the candela: evolution in the classical and the quantum world”[1]. This paper reviews the evolution of optical radiation measurements and its consequent impact on the definition of the candela. It is planned that within several years four of the base units of the SI system (kilogram, ampere, kelvin, mole) will be redefined, and the definitions of the three other base units will be reworded. For each of the definitions a mise en pratique (French for “practical realization”) shall be available, which explains how the definition can be realized in practice. The CCPR will provide the mise en pratique for the definition of the candela and will in this collaborate with the CIE, which has the responsibility for the spectral luminous efficiency functions. An Agreement between the CIE and the CIPM (International Committee for Weights and Measures) has been signed in 2007, which defines the roles of both organizations. The text of this Agreement is available on www.bipm.org/utils/common/pdf/bipm-cie_agreement.pdf.

As a consequence of a workshop on “Physiological quantities and SI units”, held at the BIPM in November 2009, the Strategic Planning Working Group has created a task group on terahertz radiation, which shall advise the CCPR on technical matters related to THz measurements requiring SI traceability.

[1] Metrologia 47 (2010) R15-R32.

L1-3 ISO/TC6/W3: Paper, Board and Pulp -Optical Properties

Liaison: Joanne C Zwinkels CA

No report.

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L1-4 ISO/TC38/SC1: Textiles: Colour Fastness & Measurement

Liaison: M Ronnier Luo GB

No report.

L1-5 ISO/TC42 Photography

Liaison: Jack Holm US

No report.

L1-6 ISO/TC130 Graphic Technology

Liaison: Danny C Rich US

ISO TC 130 held its fall meeting at DIN in Berlin, Germany, 16-23 September 2011.

Actions and plans of the Technical Committee that are of interest to the CIE

1. ISO TC 130 has sent a letter to the CIE Division 1 Director concerning the series of documents starting with CIE Publication 51 and continuing through CIE S012 and finally ISO/CIE 23603 indicating that the series of documents were weak and provided little guidance during the development of ISO 3664.

2. ISO TC 130 had agreed that they would switch all specification tolerances from CIELAB to CIEDE2000. But that decision came under criticism as the CIE has provided no guidance on how to move forward from the older CIE recommendations of CIELAB and CIE94 to adoption of CIEDE2000. It was stated to the ISO TC130 Convener that the latest recommendation is too complex and confusing and that the documents and papers published, to date, are understandable only by the creators of such metric and not by the general users of these technologies. It was proposed that existing standards in the graphic arts not be revised to include references to CIEDE2000 tolerances. This issue remained unresolved.

3. ISO TC 130 had formally adopted the stance that all instruments for the measurement of prints and printing should conform to the requirements of ISO 13655 and ISO 3664 and either irradiate the specimen with light from a source that is at least a BB rating versus CIE D50 or uses a method that reads the specimen with a UV-rich and a UV-poor daylight source and correct the total radiance factors to the levels that would have been read had the instrument had a CIE D50 source. TC 130 is not in favor of the CIE calling both the historical CIE illuminant C (representative of North Sky daylight) and CIE D50 as “Indoor daylight” TC 130 has adopted CIE D50 for its ability to render neutral colors with minimal undertone (either bluish or yellowish), a feature is that is critically important to accurate image reproduction across differing media.

4. ISO 14861 is a draft standard that is to document the process for simulating the proof of a print job using flat panel displays. One unresolved issue was the impact of the spectral nature of the source on the visual evaluation of the colors in the images. Since no graphic display actually has a CIE D50 or D65 source but rather will have either CCFL or LED source which current color management software adjusts so that the chromaticity of the white point matches the chromaticity of a standard phase of daylight. But the individual colors then simulated on the display have different spectral distributions and so potentially large amounts of metamerism. In addition, it would be interesting to know if an LED used in this kind of display application, still exhibits the lack of conformance to the CIE Luminous Efficiency function that has been reported in single LED sources. The lack of progress in CIE TC 1-69 due to influences from architectural

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lighting has given reason for some concern on the part of reproduction industry. Many large consumer product producers have significant brand equity involved in the correct rendering of the colors of the products. The CIE’s inability to get consensus on how to assess and document those sources is critical to the industry at this moment.

5. The use of a gray or near-neutral scale to set the tone reproduction of a printing device is growing in its global adoption. The requirements for making this method of "press calibration" work is the ability to map near-neutral colors from the white point of the substrate to the black point of the full tone black ink or three-color overprint ink. TC 130 continues to request guidance from CIE Division 1 on how to define visual differences between two gray stimuli that may different in chroma and hue and in obtaining a definition of the percept of gray that is linked to a CIE color metric. The recent color difference metrics, both from the CIE and from the textile industry have been shown to have major flaws in assessing colors near the neutral axis. TC 130 experts are anxious to have this issue resolved and new recommendations from the CIE that can be implemented in ISO quality assessment and certification programs for reproduction agencies.

No other actions or activities were planned or carried out that are of interest to CIE Division 1.

L1-7 ISO/IEC JTC1/SC28 Office Equipment

Liaison: Klaus Richter DE

Internet: Berlin University of Technology (TUB): http://130.149.60.45/~farbmetrik For recent publications of the TUB group see: http://130.149.60.45/~farbmetrik/XY91FEN.html (Only SC28 work on colour is described in the following report.)

The voting for a Technical Report ISO/IEC TR_29186 "Test Method of Colour Gamut Mapping Algorithm for Office Colour Equipment" ends in January 2012. The voting for a Draft International Standard ISO/IEC DIS 21118 (Revision) "Information to be included in Specification Sheets - Data Projectors" ends at 2012-05-02.

I expressed my concerns to both standard documents both as Liaison member between CIE Division 1 and ISO/IEC JTC1/SC28 in both directions and via the German National Body of SC28. However, both standard documents did not consider the reduction of the luminance contrast, the colour gamut and the colour discrimination under the office illuminance of 500 lux. The illuminance of less than 64 lux for softcopy condition of ISO TC 130 (Graphic Arts) is used. In addition ISO/IEC DIS 21118 uses a very unusual measurement of the luminance "contrast ratio" between white and black (see below). Comments of some CIE experts may be appropriate for ISO/IEC DIS 21118 before May 2012.

Background information About 10 years ago there was a kind of "marketing battle" between printer and copier manufacturers. The manufacturers advertise with resolution values 150, 300, 600, 1200, 2400, and more dots/inch. However, the visual system can resolve about 60 lines per inch (lpi) in the office viewing conditions and the viewing distance of about 50 cm. The companies recognized that about 300 dots/inch are sufficient to match the visual resolution limit. As a compromise the standard ISO/IEC 15775 for colour copiers includes the following question about output resolution: Test of the radial grating (line screens) according to the output: Can equally spaced lines be seen for radial diameters from 15 to 60 lpi (Yes/No)?. This question in the International Standard ISO/IEC 15775 helps to stop the "marketing battle" in the field of resolution values for office equipment.

Contrast ratios At present there is similar "marketing battle" with "contrast ratios", see for example the specification 2000:1 in ISO/IEC DIS 21118, Table 1. The "contrast ratio" of this draft is defined as the luminance ratio of full white projection display (for r=g=b=1) and the full black projection display (for r=g=b=0). Within the CIE and for example ISO 9241-306 "Ergonomics of human-system interaction --

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Part 306: Field assessment methods for electronic visual displays" the "standard contrast ratio" is the luminance ratio of a full white display and a black sample of at least 3x3 pixels in the white display surround. With these measurement conditions the standard luminance ratio may be 100:1. For example the optical stray light of the data projector system produces this value.

Fig. 1 defines 8 "contrast steps" no. 8 to 1 for luminance ratios between 288:1 and about 2:1. For surface colours the ratio is given in the second column. The "standard contrast ratio" 36:1 or 88,9:2,5 is based on the high quality offset range. For a display output the contrast step 228:1 (no. 8) may be reached in a room with an illuminance of less than 62 lux. However the visual contrast limit is near 100:1 and decreases with age. In an office with the standard illuminance 500 lux the reflection on the display surface may produce the contrast 36:1 (no. 5) which is the same as for surface colours.

Fig. 1.

Application example During an ISO meeting in 2011 we measured the standard contrast ratio 4:1 at the projection screen for a data projector. At the screen the illuminance was 240 lux for the white screen and 60 lux for a black sample. Therefore the projector produces an illuminance of 180 lux (three times the screen illuminance by daylight). The table illuminance at the working area was about 240 lux (by daylight with some window shutters).

The illuminance produced by the data projector increases for a viewing distance 10 m instead of 20 m (value in the meeting room) by a factor 4 from 180 to 720 lux. Then the contrast ratio is 780:60 = 13:1. In the meeting room the projection screen was behind the room wall (similar in a theater) to reduce the illuminance at the screen by the room daylight. Therefore if the data projector projects on the room wall (as in most offices), then again only a contrast range of 3:1 is possible with this data projector. If the draft ISO/IEC DIS 21118 is accepted as International Standard, then for users a

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large discrepancy between the "contrast ratio" 2000:1 in the specification sheet and 3:1 in reality is created. It may be appropriate that the CIE decides to play a more active role in this area.

Output for eight viewing conditions (contrast ratios or contrast steps) For the eight viewing conditions of Fig. 1 ISO 9241-306 has defined a grey test chart, see (24 pages, 2 MB) http://130.149.60.45/~farbmetrik/OE53/OE53F1PX.PDF For the contrast step 1 the page number 21 shows an equally spaced output, if the data projector uses the standard gamma value 2,4 in the device profile (the profile may use a less value). According to ISO 9241-306 the manufacturer of a data projector may made available 8 device profiles to solve the user wishes for equally spaced output for eight viewing conditions. There is a method in ISO 9241-306 to create these eight profiles for both Windows and Mac.

Similar ISO test charts are available for colour now, see (24 pages, 3 MB) http://130.149.60.45/~farbmetrik/OE58/OE58F1PX.PDF. Usually the contrast step for the equally spaced output for the grey series produces in addition an equally spaced colour output.

Technical Remark: It is usually sufficient that any profile change only the gamma value of the rgb data in the sRGB colour space. This produces a modified sRGB colour space for eight viewing conditions. The modified rgb values are given by the standard rgb values with the exponent "relative gamma" between 1 and about 0,47 for the 8 contrast steps (compare Fig. 1)

Summary: The viewing conditions of the emissive displays and the data projectors displays vary to a high degree. A colour metric for contrast ratios in the range 36:1 to 2:1 is needed.

The draft ISO/IEC DIS 21118 creates measurement values of a "contrast ratio" for data projectors with an example value 2000:1. This value is not appropriate for users. The visual system can resolve values of about 100:1 which decrease with age. The measurement values of the "standard contrast ratio" in a real application often creates values of 4:1. Similar the draft ISO/IEC DIS 21118 specifies 16 Million colour for the data projector output but in real applications the amount may be less than 1000. In addition the change of the colour gamut is not considered.

The "marketing battle" of contrast ratios of data projectors may be solved if a visual test of the "contrast ratio" in the real output is used. The important user question is for example: Can 15 gray or colour differences of the 16 steps be seen (Yes/No)?

It is proposed that CIE Division 1 produces a Technical Report with properties of low contrast vision. The low contrast vision produces a reduction of colours and the colour gamut which is for example only 50% for the contrast step 5 (36:1, office viewing) instead of contrast step 8 (288:1, dark room).

L1-8 International Association of Lighthouse Authorities

Liaison: Malcolm Nicholson GB

No report.

L1-9 ISO/TC159 Ergonomics

Liaison: Ken Sagawa JP

No report.