February 2014

ACTIVITY REPORT
DIVISION 1
COMMISSION INTERNATIONALE DE
L’ECLAIRAGE INTERNATIONAL COMMISSION
ON ILLUMINATION
INTERNATIONALE BELEUCHTUNGSKOMMISSION
VISION AND COLOUR
February 2014
Director:
Associate Director – Vision
Associate Director – Colour
Editor
Secretary
Prof Ronnier Luo (GB)
Dr Miyoshi Ayama (JP)
Dr Ellen Carter (US)
Dr Phil Green (GB)
Dr Michael Pointer (GB)
[email protected]
CIE Division 1 held a very successful meeting at the University of Leeds, UK on 4-6 July 2013. The
meeting opened with a one-day workshop on Colorimetry, Graphic Arts and Colour Management the
purpose of which was to explore areas of colour science that are of interest to ISO TC 130 Graphic
Technology and ICC – the International Color Consortium, who are an industry organisation
responsible for all matters to do with colour management in the image reproduction industries.
Danny Rich (Sun Chemical) represented ISO TC130 and Phil Green the ICC. About 50 people attended
the Workshop including a number via a tele-conference link. In the evening a workshop dinner was
held in a local restaurant and CIE-UK jointly hosted this event with ICC. The event was successful in
that the graphic arts representatives felt that they gained a greater understanding of some of the
recent innovations in colour science, and CIE recognised the need to recommend not just scientific
methods but industrial solutions.
The Division met for Technical Committee meetings on 5 July at the University of Leeds. The
following TCs met:
TC1-55 Uniform colour space for industrial colour difference evaluation
TC1-61 Categorical colour identification
TC1-77 Improvement of the CIE whiteness and tint equations
TC1-81 Validity of formulae for predicting small colour differences
TC1-82 The calculation of colour matching functions as a function of age and field size
TC1-83 Visual aspects of time-modulated lighting systems
TC1-84 Definition of visual field for conspicuity
TC1-85 Update CIE Publication 15:2004 Colorimetry
TC1-89 Enhancement of images for colour defective observers
TC1-90 Colour fidelity index
TC1-91 New methods for evaluating the colour quality of white-light sources
TC1-92 Skin colour database
In addition to the above, TC1-80, 1-85, 1-90, 1-91 and JTC1 met at the CIE Centenary meeting, held
earlier in April 2013 in Paris, France.
The main Division meeting was held on Saturday 6 July at Weetwood Hall, Leeds, part of the
conference facilities of the University of Leeds.
1
The following activities were closed in Leeds:
TC1-57 Standards in colorimetry
TC1-74 Methods for re-defining CIE D illuminants
R1-40 Scene dynamic range
R1-50 3D aspects of visual appearance measurement
R1-56 Skin colour database*
R1-57 Border between luminous and blackish colours*
R1-59 Calculation of self-luminous neutral scale*
*
Reporter’s report on the CIE Division 1 website.
The following activities were started in Leeds:
TC1-93 Calculation of self-luminous neutral scale: Robert Carter US
TC1-94 Visually meaningful spectral luminous efficiency functions: Janos Schanda HU
R1-60 Future colour difference-evaluation: Guihua Cui CN
In addition, TC1-92 Skin colour database (Kaida Xiao CN) was approved in March 2013 following an
email ballot.
The following Division 1 publications have appeared during the last year:
CIE 204:2013: Methods for re-defining CIE D illuminants
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.
2
VISION SECTION: TECHNICAL COMMITTEES
TC1-36 (V)
Fundamental Chromaticity Diagram with Physiologically Significant Axes
Established:
Terms of
Reference:
Chairman:
Members:
1991
To establish a chromaticity diagram of which the coordinates correspond to
physiologically significant axes.
Françoise Viénot FR
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
H Scheibner DE, P Trezona GB, and H Yaguchi JP
Consultants:
Comments have been received on the draft of Part 2 of the TC report circulated in May 2013.
Comments were dealing with:
 An error with respect to the MacLeod-Boynton chromaticity diagram that should be the same
for quanta or for energy. This error has been fixed.
 It has been proposed to include a figure showing the LMS tristimulus space, similar to Figure 1b
of the original MacLeod and Boynton paper. This figure is now included.
 There is some doubt about the chromaticity coordinates of illuminant E; to be checked.
 The new ILV is available at http://eilv.cie.co.at/. The term "tristimulus space" is not official.
Should it be replaced by "colorimetric colour space"?
 "Viewing angle” has been used in part 1. However "visual angle" is the official term. Therefore,
the official term has been used throughout.
A new version of Part 2 of the report was circulated to TC members on 2 July 2013.
TC1-42 (V)
Established:
Terms of
Reference:
Chairman:
Members:
Color Appearance in Peripheral Vision
1993
To prepare a technical report on color appearance zones for colored lights in
terms of unique hues in peripheral vision.
Miyoshi Ayama JP
I Abramov US, M Ayama JP, H Chan US, G Derefeldt SE, L Eriksson SE,
L MacDonald GB, K Okajima JP, A Yujiri JP
The Technical Report is now in the final stages of the being produced by the Central Bureau.
TC1-67 (V)
Established:
Terms of
Reference:
Chairman:
Members:
The Effects of Dynamic and Stereo Visual Images on Human Health
2005
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.
H Ujike JP
Jelte Bos NL, Graham F A Harding GB, Peter A Howarth GB, Tohru Kiryu JP, Ken
Sagawa JP, Richard H Y So HK, Brian Tansley CA, Arnold Wilkins GB, Makoto
Yoshizawa JP
The draft of Technical Report for photo-sensitive seizures developed by the editorial group in this TC
has been circulated and revised based on the comments received. The draft is now about to be
circulated for a TC ballot.
3
TC1-78 (V)
Established:
Terms of
Reference:
Chairman:
Members:
Evaluation of Visual Performance in the Real Lit Environment
2009
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.
Ronnier Luo GB
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
The TC chairman has managed to obtain all of the relevant documents from the previous chairman.
The TC members will now be contacted with a view to setting up a realistic work programme.
TC1-80 (V)
Established:
Terms of
Reference:
Chairman:
Members:
Research Methods for Psychophysical Studies of Brightness Judgements
2010
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.
Steve Fotios
Alan Chan HK, Ulrich Engelke NL, Peter Hanselaer BE, Kevin Houser US, Ásta
Logadóttir DK, Balazs Nagy HU, Keith Niall CN, Osvaldo da Pos IT, David Simmons
GB, Lou Tassinary US, Jan Vanrie BE, Minchen (Tommy) Wei US, Martijn Withouck
BE
Meetings held:
1. September 2010: 2nd CIE Expert Symposium on Appearance (Ghent, Belgium).
2. July 2011: 27th Session (Sun City, South Africa)
3. September 2012: CIE conference in Hangzhou (note; v informal as only 3 people there; made
plans as to how to respond to feedback on latest draft).
4. April 2013: during CIE mid-term session in Paris.
There are 14 members, including the chairman, and these have backgrounds in both lighting and
psychology: PhD students have been encouraged to join. This group has been reduced from the
earlier list of ~20 people to include only those who have made contributions to the work, e.g.
responded to requests for comments/feedback on draft reports.
The final committee draft was completed, with 100% vote to approve the draft, in time for the
Division 1 meeting in July 2013.
The draft is currently being edited by CIE CB to transform it to standard format prior to being issued
for the next stage of review.
TC1-82 (V)
Established:
Terms of
Reference:
The Calculation of Colour Matching Functions as a Function of Age and Field Size
2010
1. Following on from CIE Technical Report 170, to recommend a procedure for
calculating XYZ-like colour marching functions from cone fundamentals, as a
function of age and field size.
2. To deliver a computer programme for the calculations.
4
Chairman:
Members:
Jan-Henrik Wold NO
C F Andersen NO, M Brill US, Guihua Cui CN, M Fairchild US, H Fairman US, I Farup
NO, C-S Lee KR, C Li CN, K Richter DE, F Viénot FR, M Withouk BE, Y Yamuchi JP
Proposed new member from 1 January 2014: Guihua Cui (CN)
Analyses of interpolation/optimisation concept
Since a number of intersections occur between the optimised spectrum loci for different field sizes
and ages, analyses have been made to see if crossing of the loci can be avoided by some other
interpolation concept. The results show that loci intersections are unavoidable irrespective of the
interpolation method. However, since in any case the diagrams represent different observers, this
concern is probably more of an aesthetic flaw.
Limitations on age parameter
In order to evaluate the reliability of the computed cone fundamentals for elderly people, it seems
necessary to investigate all available databases, with particular regard to the scattering of the data
at different ages. The decision on an upper limit for the age parameter should be made with
reference to these investigations. The TC will thus make contact with labs (Rochester, Leeds and
others) that have determined individual LMS cone fundamentals for different field sizes and ages.
Contact will also be made with researchers at the Department of Ophthalmology, Glostrup Hospital,
University of Copenhagen, who have studied age-related changes in transmission properties of the
eye lens (in vitro).
Programming
The main structure of the computer program is established. In particular, the major part of the
Python code (program to be used for the web-application) is implemented. In addition to the ageand field-size-parameterised calculations of cone-fundamental-based XYZ colour-matching functions,
the program now also facilitates age- and field-size-parameterised calculations of MacLeod–Boynton
(l,s)-diagrams and equi-energy-normalised (l,m)-diagrams. For comparison with the existing
standards, plots and tabulations of the CIE 1931 and CIE 1964 colorimetric systems are also
implemented.
What still remains is the coding of the procedures for calculation of tristimulus values and
chromaticity co-ordinates of the maximum-saturated purple stimuli as a function of complimentary
wavelengths.
The work on the porting of Python code into MATLAB is started, but detailed coding will wait until
the Python program is finalised.
As for the facilitation of an Excel application for calculation of age- and field-size-parameterised
colour-matching functions, the committee is inclined not to leave this for the public – this to ensure
consistency between the values computed by the different applications. The committee has been
informed that colleagues at Manukau Institute of Technology, Auckland, New Zealand (the Group of
Andrew Chalmers) might be willing to volunteer to port the code into Excel. Moreover, professor
Guihua Cui (CN) (who after the Division 1 meeting in Leeds, 4-6 July, expressed his interest in
participating in the TC work) may also be supportive, in both the MATLAB and the Excel
programming.
Next TC meeting
The further progress of the committee work will be discussed at the next TC meeting, which will take
place during the CIE Division 1 Annual Meeting at NIST, Gaithersburg, Maryland, USA, June 16–17,
2014.
5
TC1-83 (V)
Established:
Terms of
Reference:
Chairman:
Members:
Visual Aspects of Time-Modulated Lighting Systems
2011
1. To investigate and report on current research on the perception of visual
artifacts of temporally modulated lighting systems, including flicker, the
stroboscopic effect, and the phantom array effect.
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.
Dragan Sekulovski NL
Pei-Ting Chou TW, Dennis Couzin DE, Jim Dakin US, Nana Itoh JP, Chan-Su Lee KR,
Tsung-Xian Lee TW, Malgorzata Perz NL, Andy Bao-Jen Pong TW, Michael
Poplawski US, Lili Wang CN, Lorne Whitehead CA, Arnold Wilkins UK, Yasuki
Yamauchi JP
The TC met in Leeds during the Division 1 meeting in June 2013. At the TC meeting, the Terms of
Reference of the TC were sharpened and the definitions of the different temporal artifacts were
discussed. A draft of the definitions is being finalized for sharing with members. In December, a
meeting with the TC chair of TC 2-76 Characterization of AC-driven LED Products for SSL Applications
was held in Taipei. At the same meeting, a presentation sharing definitions, best practices for testing
and the draft proposed measures was given. Draft sensitivity curves for the stroboscopic effect and
flicker for simple sine waves were developed based on the results of tests in the Netherlands (Perz,
Sekulovski) and China (Wang).
TC1-84 (V)
Established:
Terms of
Reference:
Chairman:
Members:
Definition of Visual Field for Conspicuity
2011
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.
Nana Itoh JP
No report.
TC1-88 (V)
Established:
Terms of
Reference:
Chairman:
Members:
Scene Brightness Estimation
2012
1. To investigate current research on brightness estimation methods using a
calibrated luminance image of a real indoor scene
2. To compare brightness estimations of real indoor scenes with those predicted
3. To recommend a method to predict the brightness of specified regions of a
scene from a luminance image of that scene
Yoshiki Nakamura JP
This TC is now formally established and will hold its first meeting in Kuala Lumpur, Malaysia in April
2014 as part of the 2014 CIE Conference Lighting Quality and Energy Efficiency.
TC1-89 (V)
Established:
Terms of
Enhancement of Images for Colour Defective Observers
2012
To study, evaluate and recommend image enhancing techniques for colour
6
Reference:
Chairman:
Members:
defective observers and to provide test procedures for the evaluation of those
techniques.
Po-Chieh Hung JP
M Ayama JP, H Chen TW, L Fernandes BR, Y Ichihara JP, Y Kishimoto JP, G Kuhn BR,
R Lenz SE, R Mochizuki JP, B Nagy HU, M Oliveira BR, S Otsuka JP, G Sharma US, F
Viénot FR, Y Yoshikawa JP
After the TC was formally activated in January 2013, seven TC meetings were held during the year
using the WebEx remote conference system prepared by the CIE Central Bureau. In these meetings,
members presented their research work, which were categorized into image enhancement methods
and evaluation methods for colour defective observers. The former was further categorized into
three types of method: changing color, changing spatial characteristics and adding texture. In the
evaluation method, methods using display and gene analyses to characterize colour defective
observers were presented.
A coarse organization of Technical Report was tentatively agreed as follows: (1) introduction/scope,
(2) definitions, (3) use-case and requirement, (4) enhancement technique, (5) test method for
enhancement technique, (6) recommendation, and (7) appendix. The chapter “Enhancement
technique” would include multiple approaches and the chapter “Test method” would include
suggested test images as well as test procedures. TC members are supposed to start drafting each
chapter in 2014.
TC1-93 (V)
Established
Terms of
Reference:
Chairman:
Members:
Calculation of self-luminous neutral scale
2013
To recommend a formula or computational method for an achromatic, neutral or
gray scale for self-luminous (i.e. non-reflective) surfaces. (This computation
complements CIE Lightness, L*, which serves a similar purpose for reflective
surfaces.)
Robert Carter US
Phil Green GB, Elizabeth Krupinski US, Robert Marcus US, Claudio Oleari IT, Kevin
Smet BE
This Technical Committee was voted unanimously by Division 1 in June 2013, and approved by CIE
Central Bureau in August 2013. Despite its brief existence, the TC has made administrative and
technical progress.
Administratively, the members and advisers have organized into four interacting subgroups to
accomplish four important goals of the TC. One subgroup (Carter, Brill) is clarifying a formula or
computational method to test against the terms of reference. Another subgroup (Oleari, Huertas,
Melgosa) is examining this and other formulae in the context of self-luminous color difference and
color space. Ideally, they will show the use of the formula or computational method in this context
(e.g., in CIEDE2000 and ΔE GP). Yet another subgroup (Marcus, Rich, Smet) is pondering the meaning
of “neutral” in self-luminous neutral scale, in anticipation of the eventual need for standards
language which can be implemented in commercial, industrial and scientific venues. The fourth
subgroup (all others and more) are seeking opportunities to test the proposed formulae in a wide
range of practical situations, so we can know the limits within which any proposed formula is useful.
A project plan reflecting this organization of the TC tasks has been posted on the CIE COLLTOOL page
for TC1-93. Also posted on COLLTOOL are ancillary materials useful to TC members. For example, the
page of COLLTOOL gives a spreadsheet showing how to make the currently proposed calculation.
Another document is a comparison of the proposed calculation with the current standard
self-luminous gray scale for medical images, the DICOM GSDF (Grayscale Standard Display Function).
7
Although each subgroup is making progress, not all have progressed to the point that their
accomplishment can be summarized here. For instance, Kevin Smet has applied for funds to pursue
related empirical research. Similarly, Rafael Huertas reports making application for funding and
doing some preliminary computations. Phil Green and a PhD student have reported stress statistics
for alternative calculations of self-luminous neutral scale.
One such calculation of self luminous neutral scale is Paul Whittle’s logarithmic “brightness”
formula, published in 1992 in Vision Research. This formula expresses the number of Just Noticeable
Differences of a target neutral scale from the background luminance of the target(s). In this sense,
the calculated neutral scale is contextualized by the background luminance, so it has characteristics
of lightness as well as brightness. The formula also computes the depth of blackness induced by a
much more luminous adjoining background. For lower contrasts from the background luminance,
the formula expresses crispening. Whittle initially demonstrated his formula with an observer task of
setting equal appearing intervals of neutral scale on a self-luminous display with unconstrained
naturalistic viewing. In theory, the formula could be used to set any number of equal-appearing
steps, for any subtense target(s) and any range of target luminance, for any background
luminance(s).
In addition to calculating the number of JNDs between a target and its background luminance,
Whittle’s formula can be used to calculate the differences in neutral appearance among targets. An
example is Carter and Huertas, Color Research and Application, 2010. In this case the neutral scale
(or color, more generally) differences among targets were shown to be an index of visual search
conspicuousness: as the value of ΔE (between a target color and distracter colors) increases, the
frequency of visual fixations on non-target colors (or shades of gray) decreases.
Yet another demonstrated application of Whittle’s formula for self-luminous neutral scale is
predicting matches of targets viewed on different background luminances. This was first reported by
Carter, in JOSA 1993. More recently Carter and Brill have a manuscript under review (since last
May!) showing a 0.974 correlation among Whittle formula calculations for 222 pairs of visually
matched targets. In this same manuscript, Carter and Brill show that Whittle’s formula can be used
to mimic the DICOM Gray Scale Display Function calculation of self-luminous neutral scale commonly
used for medical imagery, predicting minimal thresholds (from background luminances varying from
0 to 4,000 cd/m2).
Whittle, in a footnote to the 1994 book Lightness, Brightness and Transparency edited by Alan
Gilchrist, suggested that one or more of the slope parameters in his formula might vary with
background luminance. Pursuant to the task of TC1-93, Carter and Brill have shown that the
low-contrast gain (b) of Whittle’s formula increases with luminance. Making b a function of
background luminance, rather than a constant as Whittle originally supposed, improves the range of
background luminances to which the formula is applicable. This improvement is included in the
Carter Brill manuscript under review, and also in the spreadsheet posted in the TC1-93 CIE
COLLTOOL page.
Whittle’s formula has a parameter representing the proportion of retinal image contrast lost to
intraocular scattering. This proportion, 0<k<1, increases as target (or image segment) subtense
decreases. For instance, Whittle set k = 0.055 for the 2.1 degree disk targets used in his 1992 Vision
Research paper. Carter and Silverstein (JOSA A, 2012 and JSID, 2010) have shown that at least some
aspects of the effect of subtense on color appearance can be computed using Whittle’s k and the
associated mathematics. As promising as this is, there is a problem that k has been determined
empirically. Very recently, the chairman of TC1-93 has worked with Geunyoung Yoon (University of
8
Rochester, Flaum Eye Institute) to calculate k from first principles. This involves convolution of an
intraocular point spread function (PSF, including the effect of background luminance on pupil size)
with a mathematical model of the image or image segment. A publication in support of the task of
TC1-93 is envisioned.
An important effect on self-luminous neutral scale, which is not represented by any formula known
to the chairman of TC1-93, is darkening due to a highlight in the far surround. Three examples of this
are 1) the Gelb Effect, 2) Shevell, Holliday and Whittle, Vision Research, 1992, and 3) Leibowitz,
Thurlow and Mote, Journal of Experimental Psychology, 1953. Intriguingly, Shevell attributes the
effect to post retinal factors, while Leibowitz attributes it to intraocular scattering. It would be
desirable to incorporate this factor in the TC1-93 calculation of self-luminous neutral scale. Please
contact the TC1-93 chairman if you have ideas of how to accomplish this.
Finally, the objective of TC1-93 is related to other recent and ongoing CIE Division 1 projects. For
instance, neutral scale and particularly brightness are affected by the transitions from photopic to
mesopic or even scotopic conditions. At a recent CIE Division 1 color science symposium (September
2012, in Taipei), Hirohisa Yaguchi presented "An overview of mesopic vision models". This included a
model for the Helmholtz-Kohlrausch effect, HKE. See also CIE Publication 200. In essence, mesopic
brightness increases with extreme stimulation of cone primaries, beyond the effect of luminance
alone. Sanchez and Fairchild (in 2002) have quantified the HKE specifically for self-luminous displays:
Sanchez, JM – Fairchild, MD (2002): Quantification of the Helmholtz-Kohlrausch effect for CRT color
monitors, Proc. SPIE Vol. 4421, p. 607-610, 9th Congress of the International Colour Association.
Another example of relation to other ongoing CIE Division 1 work is that Whittle’s formula and other
conceivable calculations of self-luminous neutral scale are based on luminance. Luminance has a
theoretical relationship (which is controversial in its details) to cone primaries. Considering this,
sequellae to TC1-93 might involve the results of TCs 1-36, 82, 55, 57, 68 or 89, which are all related
to self-luminous neutral scale as it is derived from cone primaries.
TC1-94 (V)
Established
Terms of
Reference:
Chairman:
Members:
Visually meaningful spectral luminous efficiency functions
2013
To propose new 2 degree and 10 degree photometric observers based on the work
described in CIE Publications 086-1990 and 165:2005, as well as that of CIE TC1-36
Fundamental chromaticity diagram, and study their use in practical photometry.
Janos Schanda HU
To be provided
TC 1-94 has agreed that it start work as soon as TC 1-85 work gets all input from co-workers.
JTC1
Established:
Terms of
Reference:
Chairman:
Members:
Standard on Mesopic Photometry and Guidelines for Defining Photometric
Values in the Mesopic Region
2011
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
Liisa Halonen FI
No report.
9
VISION SECTION: REPORTERS
R1-49 (V)
Established:
Terms of
Reference:
Reporter:
Above-threshold Pulsed Lights
2009
To review methods for photometric prediction of the brightness and colour of
supra-threshold pulsed signal lights.
Malcolm Nicholson GB & Dennis Couzin US
No report.
R1-51 (V)
Established:
Terms of
Reference:
Reporter:
Reconciling Maxwell vs. Maximum Saturation Colour Matches
2010
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.
Michael Brill US
No report.
10
COLOUR SECTION: TECHNICAL COMMITTEES
TC1-55 (C)
Established:
Terms of
Reference:
Chairman:
Members:
Advisor:
Uniform Colour Space for Industrial Colour Difference Evaluation
1999
To devise a new uniform color space for industrial color-difference evaluation
using existing experimental data.
Manuel Melgosa ES
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
R Huertas ES
On July 5, 2013 a TC meeting was held in Leeds, UK with the participation of 26 people (including 7
TC members). The main conclusions of this TC meeting, and the subsequent CIE Division 1 Meeting
also held in Leeds, are as follows:
1. Research on colour-difference evaluation and new colour spaces during the past few years
proved that significant improvements upon CIELAB have been achieved. However, considering
most available experimental datasets, it was not possible to achieve a new colour space with an
associated colour-difference formula significantly better than CIEDE2000 (recently approved as a
joint CIE/ISO Standard). Therefore, at this moment it is not appropriate that CIE TC 1-55 should
recommend any new colour space with improved uniformity for industrial colour-difference
evaluation.
2. CIE TC1-55 will be closed after publication of a Technical Report with tentative title “Method for
Evaluation of the Performance of Colour-Difference Formulas”. This Technical Report will
propose a method based on the STRESS (Standardized Residual Sum of Squares) index to
evaluate the strength of the relationship between perceived and computed colour differences in
a given set of colour pairs, as well as a measurement of observers’ variability in usual
colour-difference experiments. The results achieved from this method using most advanced
colour-difference formulas and reliable experimental datasets proposed/tested by TC members
will be also reported.
3. Research on industrial colour difference evaluation must be continued. In this sense, Dr. Guihua
Cui (Wenzhou University, China) was designated as a new CIE reporter on colour differences and
uniform colour spaces devising potential future TCs.
TC1-61 (C)
Established:
Terms of
Reference:
Chairman:
Members:
Categorical Colour Identification
2001
To prepare a report describing a color categorization map for the photopic and
mesopic illumination levels.
Taiichiro Ishida JP
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)
A TC meeting was held in Leeds on July 5th, 2013. We discussed the contents of the 3rd draft report
including (1) colour categorization data obtained by Sturges and Whitfield (1995) in the final data
section, (2) final data mapped on the CIELAB color space, and (3) recommendation section. We
agreed that the report should be finished by the end of July 2013; however, the chair is still working
on it. Some modifications were made on the recommendation section. The 3rd draft will be
circulated to the members as soon as it is ready.
11
TC1-63 (C)
Established:
Terms of
Reference:
Chairman:
Members:
Validity of the Range of CIEDE2000
2001
Terms of To investigate the application of the CIEDE2000 equation at threshold,
and to CIELAB colour differences greater than 5 units.
Klaus Richter DE
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
The colour difference formula CIEDE2000 is mainly based on adjacent colour pairs with colour
differences between 1 and 5 CIELAB units. For further test of DE2000, appropriate data near
threshold (about 0.3 CIELAB units) and large colour differences (10 to 30 CIELAB units) are essential.
The chairman of TC1-55, Manuel Melgosa, has reported significant failures of both CIELAB and
DE2000 at threshold, and therefore a new committee TC1-81 was established. Now from TC1-81
about 1000 threshold colour pairs (1 JND) of Kittelmann (2009), Richter (1985), Avramopolous (1989)
and others are available. From the standard sets used in TC1-55, colour sub-sets with colour
differences smaller than 2 CIELAB units and larger than 10 CIELAB units have been produced. In
addition many results with the colour test charts of TC1-63 (CIELAB differences between 10 and 30
units) from five countries are available.
The threshold data have a much higher correlation (r = 0,99) and a lower standard deviation
compared to visual experiments which produce some visual colour difference value by a number.
Such numbers have been used for the development of DE2000. However, for thresholds the one just
noticeable difference (1 JND) is approximately the same. Richter and Seim (1987, CIE Proceedings
Venice, paper 128, Table 1) calculated for achromatic colours which change in white-black,
red-green and yellow-blue direction the standard deviation 0.15 for 1 JND.
Studies in TC1-81 show, that the luminance contrast sensitivity threshold L/L (see eILV term
17-255) is approximately constant in the office luminance range. Here the samples are specified by
the tristimulus value Y and the chromaticity of CIE colorimetry. The constant value indicates that the
Weber-Fechner law Y/Y = const is valid which is the inverse ratio of the luminance contrast
sensitivity threshold. However, the lightness L* of CIELAB and DE2000 uses the Stevens’ law which
produce a different equation: Y2/3/Y = const.
In Fig. 1 the luminance difference threshold L is shown for 1 JND for the surround luminance 100
cd/m2. In Fig. 2 the luminance contrast L/L is shown for 1 JND. The tristimulus value Y is
proportional to the luminance L. The surround luminance Lz = 100 cd/m2 may correspond to the
tristimulus value Y = 18 of the grey surround with a white border. Then the brightest colours in both
figures have a luminance factor Y = 1800 which is far beyond the office range.
12
Fig. 1: Luminance discrimination for 5 surround luminances (grey colour for tp = 0.1 s;
green colour for tp about 2 s) and comparison with data calculated from CIELAB (yellow
colour).
Fig. 1 shows that the visual systems produces a local adaptation to the adjacent samples within the
range 1.8 < Y < 180 for the viewing (presentation) time tp = 2 s. In the experiments the observer
concentrates to the two adjacent samples.
Fig. 2: Luminance contrast for 5 surround luminances and comparison with data
calculated from CIELAB (yellow colour), normalized to the grey surround luminance
Lz = 100 cd/m2.
Fig 1 and Fig. 2 include the threshold data (green colour) within the adaptation range of samples in
offices (2.5 < Y < 90), and in addition for a wider range. The yellow lines give the corresponding
results computed from CIELAB for the range 1.8 < Y < 180 and above. The conclusion seems
appropriate that the experimental data (green colour) can be described by the inverted
Weber-Fechner law L/L = const in the application range (colours in offices), see Fig. 2.
A model which explains these fundamental experimental differences has been developed by Richter
13
(2006) in a paper with the title: Relation of Weber law and Stevens law at achromatic threshold, see
the URL (11 pages, 200 kByte) http://www.ps.bam.de/BAMAT.PDF. In this paper it is assumed that
there is a local adaptation luminance La which is defined by the logarithmic average of the two
luminances at the border between either two adjacent samples or the sample and surround. This
reduces the slope by a factor two in the case of viewing separate samples on a uniform grey
background, for example for scaling of samples of colour order systems. For the short time
presentation tp = 0,1 s the slope of the experimental data may change from 4/3 to 2/3 and for long
time presentation (tp = 26) from 1 (Weber-Fechner law) to 1/2.
IEC 61966-2-1 approximates the CIELAB lightness L* by a power (or exponential) function with the
slope (1/2.4). This is approximately the value expected for a standard viewing time near tp = 2 s in
offices. This time is between viewing times tp = 0.1 s and 26 s used by Avramopolous (1989).
Summary
For adjacent colours the Weber-Fechner law seems more appropriate compared to the Stevens’ law
to describe the experimental data in the surface colour range of less than two log units. The
psychophysical basis is assumed to be a local adaptation to the two adjacent colour stimuli. For
separate samples on a grey background CIELAB and DE2000 use the Stevens’ law. Therefore both
may fail at threshold (by a factor 2) for adjacent samples in agreement with results of CIE TC1-55.
However, any final conclusion depends on the final data agreed by the members of CIE TC1-63 and
discussions in TC1-63.
Workplan (Timeframe):
1. First draft of a Technical Report (Chairman and Members): June 2014
2. Second draft which includes Comments of Committee Members: December 2014
3. Draft for voting by Committee Members of TC1-81: March 2015
4. Draft for voting by CIE Division 1: September 2015
5. Publication: 2015
TC1-64 (C)
Established:
Terms of
Reference:
Chairman:
Members:
Terminology for Vision, Colour and Appearance
2003
To monitor the terminology requirements of Division 1 including the revision of
the present ILV terms and the addition of new terms.
Sharon McFadden CA
E Carter US, O Da Pos IT, M Pointer GB, J Schanda, HU, and Manuel Melgosa SP
In 2013 two draft reports were reviewed by members and, during these reviews, several new issues
were identified. These issues have now been addressed and a new draft will be sent to members
shortly. In addition, members reached consensus on many of the remaining terms under discussion.
As requested at the 2013 Division meeting, the TC would like additional input from Division
members and other experts on whether or not you find the definitions for the following terms
acceptable. If you do not, please provide suggestions for alternative definitions.
1. Colour vision: The capacity of an organism or machine to distinguish objects based on
wavelengths (or frequencies) of the light they reflect, emit or transmit.
2. Contrast:
i.
in the perceptual sense: assessment of the difference in appearance of two or more parts of
a field seen simultaneously or successively (hence: brightness contrast, lightness contrast,
colour contrast, simultaneous contrast, successive contrast, etc.)
ii.
in the physical sense: quantity intended to correlate with perceived contrast
14
3. Contrast sensitivity:
i.
qualitatively: the ability to perceive differences between an object and its background or
between two or more objects
ii.
quantitatively: the reciprocal of any of a number of measures of sensitivity to luminance
contrast measured across a range of spatial frequencies
4. Vision (suggestions to date)
i.
Sensation and perception to recognize brightness, colour, shape, movement, etc. of the
external world as a result of radiation entering the eye
ii.
Sense which perceives the form, colour, size, movement, and distance of objects
iii.
Perception of the environment through the visual system
iv.
Ocular perception
5. Visual function: basic capabilities of the visual system including light and dark adaptation, colour
vision, spatial and temporal resolution, and stereopsis
6. Visual properties: parameters of an object that have direct, measurable visual correlates
Please send your comments and suggestions to the Chair.
The TC continues to monitor Division reports for new terminology. It will also consider suggestions
for new terms or revised definitions of Division 1 terms currently in the ILV.
TC1-68 (C)
Established:
Terms of
Reference:
Chairman:
Members:
Advisor:
Effect of Stimulus Size on Colour Appearance
2005
To compare the appearance of small (<2) and large(>20) uniform stimuli on a
neutral background.
Peter Bodrogi HU
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
G. Derefeldt SE
The Technical Report Effect of Stimulus Size on Colour Appearance is now completed and will be
published soon.
TC1-69 (C)
Established:
Terms of
Reference:
Chairman:
Members:
Colour Rendition by White Light Sources
2006
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.
Wendy Davis US
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,
15
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
No report.
TC1-70 (C)
Established:
Terms of
Reference:
Chairman:
Members:
Metameric Samples for Indoor Daylight Evaluation
2007
To investigate the derivation of a set of metameric samples to enable the
evaluation of indoor daylight simulators
B Kránicz HU
Péter Bodrogi DE, Robert Hirschler HU, Danny Rich US, Patrick Rombauts BE,
Alexander Rosemann CA, János Schanda HU
No report.
TC1-71 (C)
Established:
Terms of
Reference:
Chairman:
Members:
Tristimulus Integration
2007
To investigate methods for computing weighting tables for the calculation of
tristimulus values from abridged data.
Changjun Li CN
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
1. The least squares method (Li-Wang-Luo) has been revisited and it has been shown that the
method has a connection with the optimum method (Li-Luo-Rigg). Comparisons have been
between the least squares method, the optimum method, ASTM Table 5, ASTM Table 6, CIE-R,
Oleari zero order and second order methods for 10 nm and 20 nm intervals. It was found that
the least squares method is the best for 10 nm intervals and the optimum method is best for
20 nm intervals, with the least squares method second best. A paper entitled “Re-Visit the Least
Squares Method for Computing Weighting Tables for Tristimulus Value Computations” is in
preparation by the TC Chair and his co-authors.
2. Further comparisons were made among methods tested in 1) above with wavelength intervals at
2, 3, 4, 5, 6, 7 and 10 nm respectively. It was found that the least squares method is the best in
each case for six illuminants (D65, D50, A, F2, F7, and F11). A paper entitled “A Comparison of
Method for Tristimulus Values Computations” is in preparation by the TC Chair and his
co-authors. Combined with the test in 1) above it seems that the least squares method can be
recommended as a unified method for the computation of tristimulus values.
3. Practical considerations for computing tristimulus values have been studied including the
method of interpolation and extrapolation, and the wavelength range for colorimetric purposes.
It was found that the spline method is preferable for interpolation, and the second order
method is better for extrapolation. As for the wavelength range, it is better to use 360 nm to
780 nm rather than 380 nm to 780 nm. A paper entitled “Practical Considerations for Computing
Tristimulus Values” is in preparation by the TC Chair and his co-authors.
Time Scale
In the first half of 2014, the three above mentioned papers will be completed and circulated to TC
members for discussion. In the second half of 2014, a TC report will be written. It is hoped to
recommend a single method for the computation of tristimulus values.
16
TC1-73 (C)
Established:
Terms of
Reference:
Chairman:
Members:
Observers:
Real Colour Gamuts
2007
To recommend a gamut representative of real (non-fluorescent) surface colours
and defined by associated spectral reflectance data.
Changjun Li CN
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
Ellen C Carter US, Siu-Kei Tin
Changjun Li, M Ronnier Luo, Mike Pointer and Phil Green have done some research on generating
colour gamuts and two papers have been generated.
1. Object Colour Gamuts, Reflectance Data and Comparisons, accepted by Color research and
Application, 2013;
2. Spectral Based Gamut for Object Colours, in preparation;
The first paper reviews available gamuts and compares them with the accumulated real data sets.
Results have shown that available gamuts do not represent real data well. The second paper
presents a new gamut in terms of CIELAB L*, C* and hab under a fixed illuminant/observer and in
terms of reflectance functions.
Time Scale
Jan 2014 – Dec 2014: Further evaluate the new gamut developed by Li, Luo, Pointer and Green. Is
this gamut good enough? If not, developing a new methodology to improve it and finally gave a new
gamut. An MSc student at the University of Science and Technology, Liaoning, China will take on this
task. Results will be reported to TC members in due course.
Jan 2015 – June 2015. In this period, a technical report will be completed. To this aim, the chair will
write a draft first and further modifications will be based on the discussions and suggestions by the
TC members. It is hoped that the TC can be closed by June 2015, if not earlier.
TC1-75 (C)
Established:
Terms of
Reference:
Chairman:
Members:
A Comprehensive Model of Colour Appearance
2009
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.
Ronnier Luo UK
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
Much work has been done to derive a comprehensive appearance model as an extension to
CIECAM02. The goal is to write a paper, probably to be published in Color Research & Application,
and then to put the calculation procedure for the model into a short CIE Technical Report. Members
of the TC will be invited to test the model with Matlab code to be provided.
TC1-76 (C)
Established:
Terms of
Reference:
Chairman:
Unique Hue Data
2009
To study and report on unique hue data, including an analysis of the scatter of
those data: this to include practical viewing conditions.
Sophie Wuerger GB
17
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 TC has produced a draft report on unique hue data for both self-luminous stimuli and surface
samples. Of special interest was to see how well these two data sets agree in terms of mean settings
and variability. Currently the report contains only the CRT data, analysed in CIELUV space, for three
different illumination conditions, and the TC is discussing adding data obtained with Munsell
samples. TC members have compared the NCS unique hue data with their own CRT data and the
agreement is considered to be quite good, considering the differences in medium and illumination
condition.
TC1-77 (C)
Established:
Terms of
Reference:
Chairman:
Members:
Advisors:
Improvement of the CIE Whiteness and Tint Equations
2009
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
fluorescence.
Robert Hirschler HU
Alexandre Azevedo BR, Miyoshi Ayama JP, Michael Brill US, Ellen Carter US, David
Chen CN, Roland Connelly US, Ludovic Coppel, DE, Dan Fleming US, Phil Green GB,
Peter Hubner DE, Kenji Imura JP, Byron Jordan CA, Ichiro Katayama, JP, Ronnier
Luo GB, Danielle Oliveira BR, Claudio Puebla DE, Danny Rich US, Pat Robertson US,
Wolfgang Schlenker DE, Robert Sève FR, Tarja Shakespeare FI, Renzo Shamey US,
C Silva BR, Art Springsteen US, Klaus Wobser DE, David Wyble US, Zhiling Xu CN,
Joanne Zwinkels CA
Seyed Hossein IR, Richard Harold US, Razieh Jafari IR
1. Hirschler, Oliveira and Azevedo presented a paper at the 23rd IFATCC congress (Budapest, 8 - 10
May 2013) on whiteness determination of optically brightened textiles. Conclusions drawn from
their preliminary results (based on a rather limited number of samples):
1.1. The differences between SPEX and SPIN measurements for Spectralon and textile
specimens are very small, in the order of 1 CIE W10 unit and about 0.5 CIE Tw,10 units. The
selection of the measurement geometry (SPIN or SPEX) has thus to be based on other
considerations, such as the reproducibility of the measurements between different
instrument models.
1.2. The differences between the 45:0 nominal values and the SPIN and SPEX measured values
of the Spectralon transfer standard are in the order of ± 0.5 CIE W10 units: it may thus not
be necessary to apply a geometric correction when transferring nominal data from the
national standardizing laboratories to industrial users.
2. David Chen’s PhD thesis on Colour Measurement of Samples Containing Fluorescent Whitening
Agent was submitted to, and successfully defended at, the University of Leeds (supervisor M.
Ronnier Luo). Publication is expected in 2014.
3. Hirschler, Oliveira and Azevedo reported on research on The effect of calibration on the
inter-instrument agreement in whiteness measurements: CIE or Ganz-Griesser? Comparative
measurements were performed on 8 industrial spectrophotometers, involving over 40 PTFE,
ceramic, textile, paper and plastic samples. It was concluded:
3.1. that the CIE formula may only be used for samples which are called “white” commercially,
do not differ much in colour and fluorescence and are measured on the same type of
instrument (this is different from the original CIE recommendation which stated that the
samples should be measured on the same instrument at nearly the same time);
3.2. the Ganz-Griesser formula yields better inter-instrument agreement than the CIE formula.
18
4.
5.
6.
7.
8.
9.
CIE should consider developing a recommendation (or even a standard) for the application
of the Ganz-Griesser method and formula.
A paper was presented at the AIC 2013 Congress (8-12 July 2013, Newcastle).
Melgosa, Katayama et al. presented a paper at the AIC 2013 Congress (8-12 July 2013,
Newcastle) on Testing the performance of whiteness formulas using the PF/3 and STRESS
indices. They tested the relative merit of 19 whiteness formulae through visual results found in
four experiments using the r, PF/3 and STRESS indices. They concluded that results from r are
not in good agreement with those found using PF/3 or STRESS, which gave relatively similar
results.
Juan Lin’s PhD thesis was submitted to the North Carolina State University (supervisor Renzo
Shamey) on Factors Affecting the Perception and Measurement of Optically Brightened White
Textiles. Two publications are expected in 2014; one aims to incorporate a texture factor into
the CIE WI model, the other deals with assessment of whites for surface as opposed to
self-luminous whites.
Danny Rich (Sun Chemical) has started research on the performance of whiteness formulae
under D50 illumination.
Coppel, Andersson, Norberg and Lindberg presented a poster at the Colour and Visual
Computing Symposium (CVCS 2013, Gjøvik, Norway, 5-6 September 2013) on the Impact of
illumination spectral power distribution on radiance factor of fluorescing materials. A full paper
is to be published in 2014.
The TC had a meeting in Leeds (5th July 2013), where David Chen, Robert Hirschler and Danny
Rich reported on on-going and planned research activities (see above), and Miyoshi Ayama
reported on whiteness-related research in her laboratory as well as previous research by Uchida
and by Katayama.
The documents cited above have been uploaded on the CIE CollTool for the information of TC
members.
TC1-81 (C)
Established:
Terms of
Reference:
Chairman:
Members:
Validity of Formulae for Predicting Small Colour Differences
2010
1. To evaluate available formulae for small colour differences (<~2.0 CIELAB).
2. To define a visual threshold colour difference.
Klaus Richter DE
S Bracko SI, MR Luo GB, M Melgosa ES, G Roesler DE, T Seim NO
This committee was very busy via 3 Webex meetings since November 2013 and the meetings will
continue monthly until May 2014. About 20 documents from four of the six members were
produced in CIE COLLTOOL.
TC1-81 was established because of the following experimental result: The chairman of CIE TC1-55,
Manuel Melgosa, has presented the problem that both CIELAB and CIEDE2000 fail to describe colour
differences near threshold. Near threshold the computed colour differences from these formulae
may be by a factor 2 worse compared to larger differences.
CIE terms in eILV for L and L/L:
In some of the documents and figures the “luminance difference threshold, L” for a visual just
noticeable difference is determined and measured. L is defined as the “smallest perceptible
difference in luminance of two adjacent fields” (eILV 17-715). The value depends on the viewing
conditions including the viewing time and state of adaptation. The “contrast sensitivity, L/L” uses in
addition, the luminance L which is the average luminance of the two adjacent fields (eILV 17-255).
The tristimulus value Y is proportional to L and is used instead of L in a limited luminance range (1,5
log units). If we can describe the threshold properties of the visual systems in a luminance range 0,1
19
< L < 10000 (5 log units) with the surround Luminance Lz = 100 cd/m2 then we can expect a good
formula in the smaller surface colour range 2,5 < Y < 90. There is a similar colour difference
threshold E* in any 3-dimensional colour space, for example CIELAB.
According to the terms of reference the available formulae shall be tested. The threshold metric
formulae for the colours of surface and light mode, for example Richter (1985) and Richter and Seim
(1987, CIE Proceedings Venice, paper 128) shows properties which may solve the present problem
for describing colour thresholds. Up to now the calculations of Kittelmann (2009), and of two
members, show that the threshold formula LABJND 1985 of Richter, which is based on the contrast
sensitivity treshold L/L, may reduce the standard deviation between experimental data and the
calculation by a factor 2 compared to CIELAB. Data for DE2000 are under study.
Experimental data on colour thresholds are given for luminance variations by Lingelbach (1977), and
in addition for chromatic variations by Richter (1985) and Avramopolous (1989). Luminance
variations of more than 4 log units define a threshold metric for colours of surface and light mode.
For results, given as a function of luminance L for different surround luminances Lz between 0,1 and
1000 cd/m2 see http://130.149.60.45/~farbmetrik/TE39, http://130.149.60.45/~farbmetrik/TE50
and the following pages.
Fig. 1 (TE360-7N.PDF/PS) shows as example the experimental situation of Avramopolous (1989) for
the two presentation times tp=0,1 s and 26 s of two adjacent samples. Both samples vary in
luminance over 5 log units in a grey surround with a white border. The visual system adapts to the
grey surround with the white border and the observer has either 0,1 s or 26 s time to see a colour
threshold (border between non-visual and visual difference). The observer can increase or decrease
the luminance difference of both fields to reach the threshold. He can repeat the increase or
decrease until he is satisfied with his decision.
20
Fig. 2 (TE391-1A.PDF/PS) shows the experimental luminance difference threshold L as function of
central field luminance L. The five achromatic curves are for tp = 0,1 s and the red curve is for
tp = 26 s. The tangent property of the red curve leads to the following conclusion: the central field
acts as adapting field, and this adaptation is independent of the grey surround luminance within +/-2
log units.
Several observers report blurring if the central field luminance is 100 times larger compared to the
surround. Then the contrast sensitivity threshold L/L is no longer approximately constant. The
inverted equation L/L = constant is often called the Weber-Fechner law.
Fig. 3 (TE391-2A.PDF/PS) shows the luminance contrast sensitivity threshold. L/L = const is within 4
log units a good approximation of the experimental data. However, there is a small increase in the
slope (exponent 1,1 for L instead of 1) according to the Richter and Seim formula (1987).
Summary
The committee members of TC1-81 agreed on the following: The colour threshold data for surface
mode colours and presentation times tp >= 2 s should be included for testing. Among these are all
the data of Kittelmann (2009), Richter (1985), and about half of the data of Avramopolous (1989). A
formula which includes the Weber-Fechner law instead of the Stevens’ law (used in CIELAB and the
21
modification CIEDE2000) may reach the goal for an improved description of colour thresholds.
However, any final conclusion depends on the final data agreed by the members of CIE TC1-81.
Workplan (Timeframe):
1. First draft of a Technical Report (Chairman and Members): June 2014
2. Second draft which includes Comments of Committee Members: September 2014
3. Draft for voting by Committee Members of TC1-81: January 2015
4. Draft for voting by CIE Division 1: April 2015
5. Publication: 2015
TC1-85 (C)
Established:
Terms of
Reference:
Chairman:
Members:
Update CIE Publication 15:2004 Colorimetry
2011
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
Janos Schanda HU
Francoise Viénot FR, Alan Robertson CA, Mike Pointer GB, Hirohisa Yaguchi GB,
Ellen Carter US
In 2013 we had meetings in Paris and in Leeds, with some progress. The first sections of the
publication are ready, material for updating further sections has already been received, especially
the input from TC 1-36 and on reflection properties, and the next section of the report will be sent to
the TC in February 2014.
TC1-86 (C)
Established:
Terms of
Reference:
Chairman:
Members:
Advisor:
Models of Colour Emotion and Harmony
2011
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.
Li Chen Ou TW
M. Ronnier Luo 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
Mike Pointer GB
TC members have submitted existing psychophysical data of colour emotion and colour harmony. All
submitted data can be accessed using the CollTool. The first version of colour emotion models based
on the submitted data has been developed, as summarised in this report.
Existing psychophysical data of colour emotion and colour harmony have been submitted, including:
 Li-Chen Ou (TW) – two sets of colour emotion data, one for single colours (including Chinese and
British data) and the other for colour pairs (including those obtained in Argentina, France,
Germany, Iran, Spain, Sweden, Taiwan and the UK); two sets of colour harmony data, one based
on Chinese data obtained in the UK and the other obtained from Argentina, Iran, Spain and
Taiwan.
 Wen-Yuan Lee (TW) – two sets of colour emotion data, one for various 2D/3D basic shapes
(obtained in the UK) and the other for coloured text in various typefaces (Taiwan); one set of
colour harmony data collected in Taiwan.
 Suchitra Sueeprasan (TH) – two sets of colour harmony data, both collected in Thailand.
 Tetsuya Sato (JP) – two sets of colour emotion data, one based on a 2-point scaling method and
22

the other on a 7-point scaling method, both collected in Japan.
Ferenc Szabó (HU) – four sets of colour harmony data: monochromatic 2-colour combinations,
dichromatic 2-colour combinations, monochromatic 3-colour combinations and trichromatic
3-colour combinations. All of the data were collected in Hungary.
The submitted colour emotion data were analysed first using principal component analysis to reveal
the interrelationship between the semantic scales used (except the aesthetics-related scales such as
like/dislike or beautiful/ugly). The rotated component matrices (using the Varimax method) for each
dataset are given in Tables 1 to 7.
Table 1 Component matrix of Chinese data using square colour patches as stimuli (Ou)
Component
1
2
heavy_light
0.947
-0.168
hard_soft
0.910
-0.067
tense_relaxed
0.909
0.023
feminine_masculine
-0.832
0.073
dirty_clean
0.804
-0.466
fresh_stale
-0.672
0.579
modern_classical
-0.636
0.612
active_passive
-0.124
0.968
0.041
0.815
warm_cool
Table 2 Component matrix of British data using square colour patches as stimuli (Ou)
Component
1
2
3
active_passive
0.948
0.124
0.058
modern_classical
0.769
-0.399
-0.223
tense_relaxed
0.739
0.488
0.164
-0.637
0.340
0.596
feminine_masculine
0.172
-0.942
0.053
hard_soft
0.168
0.827
-0.195
heavy_light
-0.064
0.771
0.488
warm_cool
0.114
-0.195
0.913
fresh_stale
0.661
-0.150
-0.662
dirty_clean
Table 3 Component matrix of data using 2D basic shapes as stimuli (Lee)
Component
1
2
3
4
stale_fresh
0.986
-0.054
0.000
0.041
old_new
0.973
-0.132
-0.025
0.090
classical_modern
0.967
0.050
-0.057
0.155
sad_happy
0.943
0.057
0.108
0.279
passive_active
0.929
0.199
-0.064
0.271
dirty_clean
0.916
-0.328
0.107
-0.018
cruel_kind
0.819
-0.021
0.415
0.378
small_large
0.802
0.057
-0.349
0.171
23
serious_humorous
0.745
-0.271
0.435
0.287
empty_full
0.174
0.962
0.094
0.105
light_heavy
-0.456
0.869
-0.108
-0.083
weak_strong
0.333
0.856
-0.347
-0.126
-0.655
0.687
-0.146
0.210
0.394
-0.629
0.479
0.415
dangerous_safe
0.310
-0.404
0.781
-0.317
angular_rounded
-0.222
0.006
0.773
0.180
feminine_masculine
-0.364
0.301
-0.104
-0.836
0.270
0.524
-0.018
0.752
simple_complx
hard_soft
cool_warm
Table 4 Component matrix of data using 3D basic shapes as stimuli (Lee)
Component
1
2
3
4
dirty_clean
0.921
-0.288
-0.094
0.134
stale_fresh
0.891
-0.165
0.277
0.194
old_new
0.889
-0.349
0.210
0.044
classical_modern
0.871
-0.192
0.257
-0.030
sad_happy
0.810
-0.184
0.538
0.013
passive_active
0.739
0.080
0.567
-0.264
empty_full
-0.065
0.904
0.000
-0.208
weak_strong
-0.107
0.893
0.000
-0.268
light_heavy
-0.448
0.804
-0.155
-0.253
hard_soft
0.257
-0.769
0.493
0.266
-0.471
0.747
0.397
-0.055
cruel_kind
0.427
-0.090
0.857
0.013
small_large
0.283
-0.036
0.782
0.046
cool_warm
-0.232
0.327
0.755
-0.481
feminine_masculine
simple_complx
-0.459
0.498
-0.624
0.135
serious_humorous
0.316
-0.589
0.595
0.400
angular_rounded
-0.116
-0.229
-0.024
0.926
dangerous_safe
0.206
-0.442
-0.070
0.838
Table 5 Component matrix of Taiwanese data using coloured text (in various typefaces) as stimuli
(Lee)
Component
1
2
soft_hard
0.983
0.140
friendly_serious
0.962
0.208
heavy_light
-0.945
0.207
casual_regular
0.793
0.591
warm_cool
0.692
0.529
-0.086
0.961
luxury_plain
0.171
0.949
active_passive
0.655
0.712
complex_simple
24
Table 6 Component matrix of Japanese data using square colour patches as stimuli, assessed by
2-point scales (Sato)
Component
1
2
striking_subdued
0.987
-0.082
gaudy_plain
0.977
0.048
vivid_somber
0.974
0.066
dynamic_passive
0.956
-0.209
distinct_vague
0.842
-0.474
transparent_turbit
0.660
0.646
warm_cool
0.597
0.293
heavy_light
-0.009
-0.981
soft_hard
0.152
0.960
pale_deep
-0.288
0.942
strong_weak
0.598
-0.790
light_dark
0.657
0.729
Table 7 Component matrix of Japanese data using square colour patches as stimuli, assessed by
7-point scales (Sato)
Component
1
2
striking_subdued
0.986
-0.002
gaudy_plain
0.980
0.103
dynamic_passive
0.975
-0.147
distinct_vague
0.902
-0.335
vivid_somber
0.899
0.342
light_dark_B
0.812
0.557
light_dark_A
0.711
0.676
warm_cool
0.638
-0.156
heavy_light
0.015
-0.993
pale_deep
-0.157
0.977
soft_hard
0.213
0.957
strong_weak
0.302
-0.944
transparent_turbit
0.664
0.674
The results show that some semantic scales tended to be classified into different groups, such as
active/passive and heavy/light. These two scales were then selected for modelling. In addition,
warm/cool has been mentioned in many reports/papers and regarded as an essential description of
colour emotion, and thus warm/cool was also selected for modelling. The first version of the three
models was developed on the basis of submitted single-colour emotion data, using the framework of
the Ou et al. models of colour emotion (Ou et al. 2004a). The new models are given below:
Warm/cool:
WC= -0.89 + 0.052 Cab*[cos(hab - 50°) + 0.16 cos(2hab - 350°)]
(1)
Heavy/light:
HL = 3.8 - 0.07L*
(2)
Active/passive: AP = -3.4 + 0.067 {(L* - 50)2 + 1.93 (a* + 1)2 + 1.05 (b* - 9)2}1/2
25
(3)
Coefficients in the three models were obtained to fit the submitted data for single-colour emotion,
with the correlation coefficients given in Table 8.
Table 8 Correlation coefficients for each model and each dataset (single colours)
WC
HL
AP
British
0.84
0.86
0.87
Chinese
0.82
0.87
0.92
Japanese 2-point
0.78
0.94
0.90
Japanese 7-point
0.84
0.97
0.87
2D basic shapes
0.89
0.91
0.96
3D basic shapes
0.91
0.68
0.82
mean
0.85
0.87
0.89
The three models were tested by means of the additivity theory (Ou et al. 2004b) using the colour
pair emotion data submitted. The additivity theory of colour emotion can be described in the
following:
E = ((E1 + E2)) ⁄ 2
(4)
where E is the colour emotion value for a colour pair made by colours 1 and 2; E1 and E2 are colour
emotion values for colours 1 and 2.
Table 9 demonstrates the test results, showing somewhat satisfactory predictive performance, with
an average correlation coefficient of 0.78 for warm/cook, 0.80 for heavy/light and 0.81 for
active/passive.
Table 9 Predictive performance of each model using the additivity theory (Ou et al. 2004b), in terms
of correlation coefficients for colour pair emotion data submitted to the TC
WC
HL
AP
Argentina
0.85
0.76
0.87
British-1
0.65
0.67
0.72
British-2
0.77
0.78
0.80
Chinese
0.76
0.79
0.74
French
0.81
0.77
0.81
German
0.82
0.87
0.79
Iranian
0.73
0.83
0.85
Spanish
0.84
0.77
0.85
Sweden
0.81
0.90
0.86
Taiwanese
0.83
0.82
0.77
mean
0.78
0.80
0.81
References
Ou L, Luo MR, Woodcock A, Wright A (2004a). A study of colour emotion and colour preference, Part
I: colour emotions for single colours. Color Research and Application, 29 (3), 232-240.
Ou L, Luo MR, Woodcock A, Wright A (2004b). A study of colour emotion and colour preference, Part
II: colour emotions for two-colour combinations. Color Research and Application, 29 (4), 292-298.
26
TC1-90 (C)
Established:
Terms of
Reference:
Chairman:
Members:
Observers
Colour Fidelity Index
2013
To evaluate available indices based on colour fidelity for assessing the colour quality of
white- light sources with a goal of recommending a single colour fidelity index for
industrial use.
Hirohisa Yaguchi JP
Peter van der Burgt NL, Jeff Zawada US, Esther de Beer NL, Peter Bodrogi DE, Kevin
Smet BE, Lorne Whitehead CA, Ferenc Szabó HU, Günther Heidel DE, Janos Schanda
HU, Werner Jordan DE, Richard Young DE, Ronnier Luo GB, Sophie Jost FR, Kenjiro
Hashimoto JP, Ayako Tsukitani JP, Tadashi Yano JP, Osvaldo da Pos IT, Yoko Mizokami
JP, Wendy Davis AU, Shinji Kobayashi JP, Yoshi Ohno US, Françoise Vienot FR, Klaus
Richter DE, Takayoshi Fuchida JP, Po-Chieh Hung JP, Tomoko Kotani JP, Josep Carreras
ES, Aurelien David US, Minchen Wei US, Pedro Pardo ES
Yandan Lin CN, Andreas Kraushaar DE, Peter Karp DE
Activities in 2013:
TC1-90 had two meetings during 2013. The first meeting was held on 17 April in Paris. The work plan
was discussed and fixed as follows:
1. To gather reliable experimental data assessing colour fidelity. (Div.1 Meeting 2014)
2. To analyze the data by proposed colour fidelity indices. (End of 2014)
3. To write a report to propose the new CIE CRI. (Middle of 2015)
In the meeting, a couple of members gave presentations. Yaguchi explained the calculation scheme
of current CIECRI. Luo explained nCRI and differences from the current CIECRI. Mathematical test
samples (HL17) were used as well as additional 210 test samples (180 metamers, 5 skin colours and
10 art paintings) in nCRI. Smet also explained their application program: the visualization of the
practical examples of 17 samples under test and reference illuminants. Whitehead showed the
summary of the recent work in making real printed samples based on the HL17 mathematical
sample set. Schanda explained his experiment testing lamps with different colour temperature. Luo
also showed a psychophysical method for assessing colour rendering using 6 test lamps with
different CRI. Mizokami showed recent data on the evaluation of uniform colour spaces for
calculation of colour difference.
The second meeting was held on 5 July in Leeds during the Division 1 meeting. Luo explained the
latest version of nCRI, software to calculate nCRI (ver. 10) and related visual experiments. Tsukitani
reported calculation results on the correlations of nCRI and current CRI. Mizokami reported
calculation results on the correlations of nCRI and various indices (CRI, CRI CAM02, CQS, FCI, and
GAI), using various types of light sources including FL, LEDs, and HID. Schanda explained his
experiment testing the color fidelity of a classic FL and three-band FL. da Pos reported the new
system (or method) to evaluate color in a psychophysical experiment asking how much was the color
of test sample similar to Yellow, Red, Blue, Green, White, Black. Yaguchi introduced the Japan Color
Research Institute (Dr. Kobayashi & Dr. Komatsubara) data testing correlation between CRI 8 test
samples and new test color set.
In the second part of the meeting held in the afternoon, we discussed about a visual experiment as
following contents,
how?
which test color samples should be used?
which light sources should be used?
background?
who?
when?
27
The chairman will prepare a guideline for a method to carry out a visual evaluation experiment.
The future meetings are scheduled as follows:
28-30 April, 2014, Kuala Lumpur, Malaysia
16-17 June, 2014. Division 1 Meeting at NIST, USA
TC1-91 (C)
Established:
Terms of
Reference:
Chairman:
Members:
Observers:
New Methods for Evaluating the Colour Quality of White-Light Sources
2012
To evaluate available new methods for evaluating the colour quality of white-light
sources with a goal of recommending methods for industrial use. (Methods based
on colour fidelity shall not be included: see TC1-90).
Yandan Lin CN
Esther de Beer, Laura Bellia, Peter Bodrogi, Takayoshi Fuchida, Yoshie Imai, Sophie
Jost, Ming Ronnier Luo, Yoshi Ohno, Janos Schanda, Kevin Smet, Ayako Tsukitani,
Minchen Wei, Tsung-Hsun Yang, Tadashi Yano
Peter Karp, Jeff Zawada, Hirohisa Yaguchi
In 2013 TC1-91 established the membership with 15 members and 3 observers. The TCC has finished
Webex training and a TC1-91 room in the CIE Colltool has been established for document exchange.
The first meeting of TC1-91 was held during the CIE Paris meeting, and the second meeting was hold
in Leeds in July, both in 2013. The minutes of these two meetings are available.
The first round of collecting existing data got feedback from 8 members with 5 proposed methods,
which are CCRI, CQS, TCI, MCRI and PS. The second round of collecting description of details of
method calculation got feedback from FCI and MCRI. Further data are still needed for data analysis
and possible international parallel experiments. This is still on the way of preparation. A small group
of members started to analyze the application-based method and compare the current existing
methods. Results are expected to be collected before CIE 2014 Malaysia meeting.
In 2014, TC 1-91 plan to meet in Malaysia in April and in NIST in June (The TCC will participate via
net-meeting in June). A Webex meeting will be held in the second half of the year.
TC1-92 (C)
Established:
Terms of
Reference:
Chairman:
Members:
Skin Colour Database
2013
1. To investigate the uncertainty in skin colour measurement and to recommend
protocols for good measurement practice.
2. To tabulate skin colour measurements that accord with these protocols
covering different ethnicity, gender, age and body location.
Kaida Xiao CN
Paula Alessi US, Peter Bodrogi DE, Francisco Imai US, Esther Perales ES, Peili Sun
TW, Suchitra Sueeprasan TH, Wen Luo UK
Work Plan:
 To investigate uncertainty in skin colour measurements (1-12 months)
 To recommend a protocol for skin colour measurements (13-18 months)
 To combining existing skin colour databases (19-36 months)
 To conduct skin colour measurements (19-36 months)
 To development a skin colour database (37-42 months)
 To write a TC report (42-48 months)
28
Progress:
 Skin colour measurements have been conducted at Manchester Metropolitan University, UK,
using a spectrophotometer.
 A skin reflectance re-construction algorithm has been devised based on current skin colour
database at the University of Science and Technology Liaoning, China.
 In the University of Liverpool, in collaboration with the University of Leeds, skin colour
measurements will be conducted using a spectrophotometer, a spectroradiometer, a digital still
camera and a 3D camera between April to December 2014.
 Skin colour measurements have been planned at Chulalongkorn University, Thailand and at the
University of Alicante, Spain.
29
COLOUR SECTION: REPORTERS
R1-42 (C)
Established:
Terms of
Reference:
Reporter:
Extension of CIECAM02
2007
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
Changjun Li CN
Brill MH [Color Res Appl 2006; 31: 142-145] and Brill and Süsstrunk [Color Res Appl 2008; 33:
424-426] found that CIECAM02 has yellow-blue and purple problems and gave partial solutions.
Recently Li CJ and his co-authors have given a full solution to the yellow-blue and purple problem.
Firstly, they found that there are many matrices which repair the yellow-blue and purple problems
simultaneously. Then they gave an optimum solution to the problems. The papers are given below.
Relevant publications:
Li CJ, Ji CJ, Luo MR, Melgosa M, Brill MH. CAT02 and HPE Triangles. Color Res Appl, Accepted,
October 28th, 2013.Li CJ, Luo MR and Wang ZF, Different Matrices for CIECAM02, Color Research
and Application. DOI: 10.1002/col.21765, 2012.
Jun Jiang, Changjie Ji, M. Ronnier Luo, Manuel Melgosa, Michael H. Brill and Changjun Li, An
Optimum Solution to the CIECAM02 Yellow-Blue and Purple Problems, submitted to Color Research
and Applications
R1-52 (C)
Established:
Terms of
Reference:
Reporter:
Spectral Data Interpolation
2010
To review the methods, and make a recommendation for the interpolation of
existing, highly structured source spectra, including the FL illuminants, for
colorimetric calculations.
Hugh Fairman US
No report.
R1-53 (C)
Established:
Terms of
Reference:
Reporter:
Gloss Perception and Measurement
2011
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.
Frédéric Leloup BE
The work related to this reportership was finalized in 2013 and the resulting document published as
a paper in Color Research & Application: Leloup, FB, Obein, G, Pointer, MR and Hanselaer, P (2013),
Toward the soft metrology of surface gloss: A review. Color Res. Appl. doi: 10.1002/col.21846.
Since then new experiments are planned that relate to gloss perception and measurements within a
3-year European project that started in early 2014. An annual update will be provided that includes
other work related to the field, for example performed by vision scientists.
30
R1-58 (C)
Established:
Terms of
Reference:
Reporter:
Liaison with ISO TC130 Graphic Technology
2012
To investigate and respond to ISO TC130 Graphic Technology on matters
concerned with colorimetric calculations.
Phil Green GB
A joint workshop with ISO TC130 and ICC was held on 4 July, 2013, in conjunction with the D1
meetings in Leeds, UK. Presentations from the meeting are available at
http://www.color.org/events/colorimetry.xalter. The topics discussed were:
 Colour difference metrics
 Surface of real colour gamuts
 Modifications to CIECAM02 colour appearance model
 Measurement of fluorescence
 Recent work on blackness
The workshop made significant progress on understanding these issues and the concerns in graphic
arts. The ISO TC130 WG3 meeting in Berlin considered that WG3 is now able to move ahead with
defining tolerances and colour difference metrics in its standards.
Other outstanding issues raised by the D1-TC130 liaison, and still to be progressed in D1, are:
a. Over-range L* values for fluorescing materials
b. Assessment of LED-based sources used to simulate D50 illuminants in viewing booths
This Reportship will continue to address these matters of concern to TC130. It may not be possible
to resolve all outstanding issues during this Reportership, as they relate to matters where there are
ongoing discussions within the relevant TCs of D1.
R1-60 (C)
Established:
Terms of
Reference:
Reporter:
Future colour-difference evaluation
2013
To report on publications that relate to colour-difference evaluation and uniform
colour spaces.
Guihua Cui CN
Sources of Publications
The publications that relate to colour difference or colour spaces in this report were published in
2013 and come from the following resources:
1. Wiley Online Library: 29 papers or book chapters;
2. OSA OpticsInfoBase: 65 papers;
3. Imaging.org Digital Library: 8 papers;
4. AIC2013 Conference: 12 papers;
5. IEEE Xplore Digital Library: 45 papers.
Most of the above publications relate the applications of colour difference or colour spaces.
However, there are 29 publications1-29 that relate to colour-difference evaluation or uniform colour
spaces.
A New Uniform Colour Space – ULAB
Kim published a new uniform colour space – ULAB1 in Color Research and Application and presented
part of the test results at the AIC2013 – 12th International AIC Congress.25 ULAB is derived from
CIELAB colour space and can be converted to and from CIELAB. Unlike the modified CIELAB
31
colour-difference formulae, ULAB incorporates corrections for lightness, chroma, and hue
differences into its colour coordinates. Kim reported that for small magnitude colour difference data,
ULAB gives performance as good as the more complicated formulae such as CIEDE2000.
CIELAB to ULAB Colour Coordinates
LU = 10 ln (1 + 1.2Y + 0.02Y3),
where Y is the CIE tristimulus value and transformed from L*:
(1)
  L * 16 3
if L*  8

Yn 
  116 
Y 
3
 Y  3  L *
if L*  8
 n  29 
ln1  0.065(eC*)
CU 
0.036
(2)
(3)
where e is calculated by using the data in Table 1 as follows:
 h h 
e  ei  (ei1  ei ) ab i 
 hi1  hi 
if
hi  hab  hi1
(4)
Table 1. The relation among the hab, the chroma pre-scaling factor (e) and the hU
i
hi(hab)
ei
hU,i
1
2
3
4
5
6
0
80 + 0.2L*
195 - 0.25L*
260 - 0.15L*
312 - 0.2L*
360
1
0.95 - 0.004L*
1.05
1.6 - 0.0075L*
0.12 + 0.0075L*
1
0
90
180
240
300
360
hU is calculated by using the data in Table 1 as follows:
 ei


1 
hU  hU ,i  (hU ,i 1  hU ,i ) e

 ei
1
 ei 1 
aU  CU coshU 
if
hi  hab  hi 1
bU  CU sinhU 
(5)
(6)
(7)
Inverting ULAB to CIELAB
  Y 1 3
116   16
Y

L*    n 3
  29   Y 
  3   Y 
 n

Y  6 
if
 
Yn  29 
3
Y  6 
if
 
Yn  29 
3
where the CIE tristimulus value Y is calculated from LU by using following equations:
Y=r+s;
32
(8)
1
1
3
3
 q
 q
d 
d 
 , and s     
 ,
where r     
 2
 2
108 
108 



 L 
3
where q  501  exp  U  , and d  460  27q 2 .
 10 

exp 0.036CU  1
C* 
,
0.065e
(9)
where e is calculated using the data in Table 1 as follows:
e
hU ,i 1  hU ,i
 hU ,i 1  hU   hU  hU ,i 

  

e
e
i
i 1

 

if
hU ,i  hU  hU ,i 1
(10)
hab is calculated by using the data in Table 1 as follows:
 e  ei 

hab  hi  (hi1  hi )
 ei1  ei 
a*  C * coshab 
if
hU ,i  hU  hU ,i1
b*  C * sin hab 
(11)
(12)
(13)
ULAB Colour Difference
Differences between two colour stimuli denoted by subscripts 1 (usually the reference or the
standard) and 2 (the test or the batch) shall be calculated as follows:
LU  LU , 2  LU ,1
(14)
aU  aU , 2  aU ,1
(15)
bU  bU , 2  bU ,1
(16)
CU  CU , 2  CU ,1
(17)
hU  hU , 2  hU ,1
(18)
h
HU  2 CU ,1CU , 2 sin U 
2

(19)
EU between two colour stimuli is calculated as;
1
EU 
1.33
 LU

 kL
2

  CU 2  HU 2

(20)
or
 L
EU  0.75  U
 kL
where kL = 1 for the reference condition.
33
2

  aU 2  bU 2

(21)
New Colour-difference Datasets
1. Black Dataset
Shamey etc. 5 conducted a study to develop a specific visual dataset comprising black-appearing
samples with low lightness (L* ranging from approximately 10.4 to 19.5), varying in hue and chroma,
evaluating their visual differences against a reference sample, and testing the performance of major
colour-difference formulae currently in use as well as OSA-UCS-based models and more recent
CAM02 colour-difference formulae including CAM02-SCD and CAM02-UCS models. The dataset
comprised 50 dyed black fabric samples of similar structure, and a standard (L*= 15.33, a* = 0.14,
b* = −0.82), with a distribution of small colour differences, in ΔE*ab, from 0 to approximately 5. The
visual colour difference between each sample and the standard was assessed by 19 observers in
three separate sittings with an interval of at least 24 hours between trials and using an AATCC
standard grey scale for colour change: a total of 2850 assessments were obtained. A third-degree
polynomial equation was used to convert gray scale ratings to visual differences. The Standard
Residual Sum of Squares index (STRESS) and Pearson's correlation coefficient (r), were used to
evaluate the performance of various colour-difference formulae based on visual results. According
to their analysis of STRESS index and correlation coefficients CAM02 colour-difference equations
exhibited the best agreement against visual data with statistically significant improvement over the
other models tested. The CIEDE2000 (1:1:1) equation also showed good performance in this region
of the colour space.
2. Fogra Roses Dataset
Kraushaar11 reported a new colour difference dataset to address the specific needs of the graphic
arts industry. An experiment has been designed with 1288 colour pairs. Concretely 46 colour centres
of the Fogra media wedge and 28 randomly intra- and supra-threshold test colours around each of
them have been observed by 32 observers. The pair comparison constant stimuli method has been
used by means of three grey reference pairs comprising colour differences of ΔL = 1, 3 and 5. The
performance of established and modern colour difference formulae has been evaluated with the
new dataset. DIN99o (or DIN99b) and CIEDE2000 outperformed the other metrics tested.
3. Gholami Dataset
Gholami etc. 27 presented an experimental data at the AIC2013 Congress, Newcastle, UK in July 2013,
to study the effect of background lightness on colour-difference evaluation with 28 polyester sample
pairs prepared in seven colour centres. The visual assessment experiments were conducted by 20
observers using the grey scale method in three separate phases. In each phase, the observers
assessed the colour difference between the pairs on one of the three neutral backgrounds included:
black, grey and white. They found that for yellow and orange samples the perceived colour
differences on the white background had the largest values and the black background showed the
smallest values. For the other samples, the white background led to the smallest values of the
perceived colour difference and the grey background led to the largest values. In the other part of
their study, the correlation between the visual colour difference and the computed colour difference
using CIELAB was investigated for each background. They also found that increasing the lightness of
the background leads to a decrease in the degree of correlation between the perceived and
computed colour difference. The best correlation between visual and computed colour difference
was obtained for the black background.
References
1. Kim, D.-H. (2013), The ULAB colour space. Color Res. Appl.. doi: 10.1002/col.21854
2. Bodrogi, P., Brückner, S., Krause, N. and Khanh, T. Q. (2013), Semantic interpretation of color
differences and color-rendering indices. Color Res. Appl.. doi: 10.1002/col.21798
3. Pant, D. R. and Farup, I. (2013), Geodesic calculation of color difference formulas and
34
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
comparison with the munsell color order system. Color Res. Appl., 38: 259–266. doi:
10.1002/col.20751
Fairchild, M. D. (2013) High-Dynamic-Range Color Space, in Color Appearance Models, John
Wiley & Sons, Ltd, Chichester, UK. doi: 10.1002/9781118653128.ch21
Shamey, R., Lin, J., Sawatwarakul, W. and Cao, R. (2013), Evaluation of performance of various
color-difference formulae using an experimental black dataset. Color Res. Appl.. doi:
10.1002/col.21844
Melgosa, M., Alman, D. H., Grosman, M., Gómez-Robledo, L., Trémeau, A., Cui, G., García, P. A.,
Vázquez, D., Li, C. and Luo, M. R. (2013), Practical demonstration of the CIEDE2000 corrections
to CIELAB using a small set of sample pairs. Color Res. Appl., 38: 429–436. doi:
10.1002/col.21751
Wen, C.-H., Lin, Y.-Y., Huang, P.-C., Hsu, T.-W., Chen, H.-H. and Chang, K.-C. (2013), 41.4:
Subjective Image Quality of Viewing Angle beyond Color Difference Metric in FPD. SID
Symposium Digest of Technical Papers, 44: 574–577. doi: 10.1002/j.2168-0159.2013.tb06274.x
Liu, H., Huang, M., Liu, Y., Wu, B., Xu, Y., Liao, N., Cui, G. (2013), Color-Difference Evaluation for
Digital and Printed Images. Journal of Imaging Science and Technology, 57(5): pp.
50502-1-50502-9(9)
Li, C., Luo, M. R., Sun, P.-L. (2013), A Modification of CIECAM02 Based on the
Hunt‐Pointer‐Estevez Matrix. Journal of Imaging Science and Technology, 57(3): pp.
30502-1-30502-8(8)
Chen, S.-H., Chen, H.-S., Ohta, N., Luo, M. R. (2013), The Effect of Chromatic and Lightness
Components for Preferred Skin Color Reproduction on a Display. Journal of Imaging Science and
Technology, 57(3): pp. 30501-1-30501-12(12)
Kraushaar, A. (2013), Fogra Roses – Developing a colour difference dataset for the graphic arts.
Color and Imaging Conference, 21st Color and Imaging Conference Final Program and
Proceedings , pp. 92-95(4)
Asano, Y., Fairchild, M. D., Blondé, L. (2013), Observer variability experiment using a
four-primary display and its relationship with physiological factors. Color and Imaging
Conference, 21st Color and Imaging Conference Final Program and Proceedings , pp. 171-176(6)
Lin, J., Shamey, R. (2013) The Role of Parametric Factors on Visual Assessment of Camouflage
Substrates. Color and Imaging Conference, 21st Color and Imaging Conference Final Program and
Proceedings , pp. 134-142(9)
Liu, H., Huang, M., Cui, G., Luo, M. R., and Melgosa M. (2013), Color-difference evaluation for
digital images using a categorical judgment method. JOSA A, 30(4): pp. 616-626 (2013)
Lucassen, Marcel P; Gevers, Theo; Gijsenij, Arjan; Dekker, Niels (2013), Effects of chromatic
image statistics on illumination induced color differences. JOSA A, 30(9): pp.1871-1884
Tong, Q., Xu, H., Gong, R. (2013), Testing color difference evaluation methods for color digital
images. Chinese Optics Letters, 11(7): pp.073301Cao, R., Trussell, H J., Shamey, R. (2013), Comparison of the performance of inverse
transformation methods from OSA-UCS to CIEXYZ. JOSA A, 30(8): pp.1508-1515
HUANG, M., CHEN, G., LIU, H., CUI, G., LUO, M. R., LIAO, N., MELGOSA, M., ZHANG, Y., ZHENG, C.
(2013), A Comparison of Different Psychophysical Methods for Color-Difference Evaluation.
AIC2013 – 12th International AIC Congress, pp525-528
Eric KIRCHNER, Lan NJO, Marcel LUCASSEN (2013), Calculating Verbal Descriptions of Color
Difference Components. AIC2013 – 12th International AIC Congress, pp529-532
Haoxue LIU, Min HUANG, Guihua CUI, M. Ronnier LUO, Manuel MELGOSA (2013), Perceptual
Color-Difference Thresholds for Images under Different Viewing Conditions. AIC2013 – 12th
International AIC Congress, pp533-536.
Dibakar Raj PANT, Ivar FARUP, Manuel MELGOSA (2013), Analysis of Three Euclidean
Color-Difference Formulas for Predicting the Average RIT-DuPont Color-Difference Ellipsoids.
AIC2013 – 12th International AIC Congress, pp537-540.
35
22. Masami KONO, Naoya HARA, Haruyo OHNO (2013), Relationship between Subjective
Contrast and Color Difference based on CAM02-UCS. AIC2013 – 12th International AIC Congress,
pp541-544.
23. Min HUANG, Haoxue LIU, Guihua CUI, M Ronnier LUO, Ningfang LIAO, Manuel MELGOSA, Yaoju
ZHANG, Chongwei ZHENG (2013), Assessing Color Differences in a Wide Range of Magnitudes.
AIC2013 – 12th International AIC Congress, pp1534-1537.
24. Guihua CUI, M Ronnier LUO, Min HUANG, Haoxue LIU, Yuxin GAO, Yaoju ZHANG, Chongwei
ZHENG (2013), Assessing Colour Differences near the Neutral Axis. AIC2013 – 12th International
AIC Congress, pp1538-1541.
25. Dong-Ho KIM (2013), Colour-Discrimination Ellipses in the ULAB Colour Space. AIC2013 – 12th
International AIC Congress, pp1542-1544.
26. Omar GOMEZ, Francisco J. BURGOS, Esther PERALES, Elísabet CHORRO, Francisco M.
MARTÍNEZ-VERDÚ, Jaume PUJOL (2013), Preliminary Comparative Performance of the AUDI2000
and CIEDE2000 Color-difference Formulas by Visual Assessments in a Directional Lighting Booth.
AIC2013 – 12th International AIC Congress, pp1545-1548.
27. Atena GHOLAMI, Saeideh GORJI KANDI, Mohammad Amani TEHRAN, Faezeh SAEDI (2013),
Dependency of Visual Color Difference to Background Lightness. AIC2013 – 12th International
AIC Congress, pp1549-1552.
28. Sarah Hiwon CHUNG, YungKyung PARK (2013), Analysis of Color Difference Depending on Fabric
through Digital Media: Focusing on the Color in Blue Series. AIC2013 – 12th International AIC
Congress, pp1553-1556.
29. Nick HARKNESS (2013), Which Delta E? A Review of the Options. AIC2013 – 12th International
AIC Congress, pp1557-1560.
36
LIAISONS
L1-1
Liaison:
AIC (Association International de la Couleur)
Paula Alessi
The 12th AIC quadrennial Congress was hosted by The Colour Group (Great Britain) from July 8-12,
2013. The venue was The Sage Gateshead located on the River Tyne by the city of Newcastle, UK.
The Congress theme was “Bringing Colour to Life”. 538 people registered in advance, but there were
600 individual delegates total through daily registrations. Delegates represented 48 different
countries. There were 5 full days of meetings with 203 oral presentations, 270 posters, 6 symposia,
keynote speakers and AIC Study Groups. It was a Congress to be remembered. There is an updated
book of abstracts for AIC2013 that is available for free download from http://www.aic2013.org/.
To access the abstracts go to the web page and right-click on Book of Abstracts in the Downloads
section (right-hand side of the page).
New officers for the Executive Committee were elected at the General Assembly on July 10, 2013.
They are:
President:
Javier Romero (Spain)
Vice President:
Nick Harkness (Australia)
Secretary/Treasurer:
Tien-Rien Lee (Taiwan)
Ordinary members:
Gabriela Nirino (Argentina)
Jin-Sook Lee (Korea)
Maria-João Durão (Portugal)
Nancy Kwallek (USA)
Past President:
Berit Bergström (Sweden)
Paula Alessi (USA) and Frank Rochow (Germany) will be the Auditors of the AIC.
During the Congress the coveted AIC Deane B. Judd Award was presented to Dr. Roy S. Berns from
The Munsell Color Science Laboratory at Rochester Institute of Technology. Dr. Berns gave a special
talk after receiving the Award.
Two new regular members joined AIC: Colour Research Society of Canada (CRSC), Canada and Colour
Group - Italian Colour Association, Italy
The AIC is calling for a celebration of the International Colour Day on March 21, 2014. They hope
that each country will create memorable colour activities on that day all around the world. Please
find more details about International Colour Day at:
http://www.aiccolour.org/index_archivos/colorDay.pdf
The AIC 2014 Interim Meeting will be held in Oaxaca, Mexico from October 21-October 24. It will be
hosted by Asociación Mexicana de Investigadores del Color. The theme will be Colors, Culture, and
Identity: Past, Present and Future. Conference topics are Folklore expressions about colour, History
of colour, Local stories about colour, Ancient pigments and natural local dyes, Colour as an identity
means, Anthropology, Visual semiotic and psychology, Art and crafts, and Restoration. A Call for
Papers has already been sent out with submissions due by February 21, 2104. Please see
www.aic2014.org or www.amexinc.org.mx for more details.
The AIC 2015 Midterm Meeting will be held in Tokyo, Japan from May 19-22. It will be hosted by The
Color Science Association of Japan. The theme will be Color and Image. Please see www.aic2015.org
or [email protected] for more details.
37
The AIC 2016 Interim Meeting will be held in Santiago, Chile from Octobet 18-22. It will be hosted by
The Chilean Color Association of Japan. The theme will be Color in Urban Life: Usability in Images,
Objects, and Space. Please see www.aic2015.org or [email protected] for more
details.
The AIC 2017 13th Congress will be held in Jeju, Korea from October 16-20. It will be hosted by The
Korea Society of Color Studies. The venue will be the International Convention Center Jeju. Please
see www.color.or.kr for more details.
The AIC Annual Report (formerly known as the AIC Newsletter) is available online at
www.aic-colour.org. Please visit the website for all the latest news in the international color world.
L1-2
Liaison:
CCPR (Comite Consultatif de Photometrie et Radiometrie), BIPM
Michael Stock
The CCPR meets about every two years at the BIPM in Sèvres, France, bringing together some 30-40
experts from its member NMIs (National Metrology Institutes). The last meeting took place on 23-24
February 2012. The CCPR working groups met during the same week and again on 22 and 23 April
2013. The next meeting of the CCPR will take place in September 2014. On 1 January 2013, Dr.
Takashi Usuda from the National Metrology Institute of Japan (NMIJ) became the new President of
the CCPR, following Dr. Franz Hengstberger. General information on the work of the CCPR can be
found on www.bipm.org/en/committees/cc/ccpr.
The CCPR 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 spectral regular transmittance, for
luminous intensity and luminous flux, and for spectral responsivity in the visible and infrared regions.
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). They cover the fields of spectral irradiance,
spectral responsivity, luminous intensity, luminous flux, spectral diffuse reflectance and spectral
regular transmittance.
It is expected that in the near future four of the seven base units of the SI system will be redefined:
the kilogram, the ampere, the kelvin and the mole. Each of these units will be based on a fixed
numerical value of a fundamental constant: the Planck constant, the elementary charge, the
Boltzmann constant and the Avogadro constant. The impact of these changes on the candela will be
insignificant. To give guidance on how the units can be realized in practice, a so-called mise en
pratique (French for “practical realization”) will be published for each base unit. The candela will not
be redefined, but it is planned to change the wording of its definition. An important development in
the field of photometry is the introduction of the spectral luminous efficiency functions for mesopic
vision. For these reasons, the Strategic Planning Working Group of the CCPR held in 2012 a workshop
on the mise en pratique of the candela to which representatives of the CIE had been invited. The
workshop had the objective to guide the direction and to coordinate possible joint work between
the CIE and the CCPR to prepare a new mise en pratique for the candela. The final decision was that
a concise mise en pratique would be written by experts from the CCPR and that an additional more
extensive document Principles Governing Photometry shall be published by a joint CCPR-CIE task
group, which is be chaired by Dr. Ohno (NIST).
Another workshop was organized on 22 April 2013, on SI units for Photometry and Radiometry,
again with representation from the CIE. One of the topics was a discussion of the proposal to replace
38
the candela as the photometric SI base unit by the lumen. The CIE Division 2 Director, Dr Peter
Blattner presented the outcome of discussion within CIE which resulted in the recommendation that
“in the absence of compelling reasons to change from the candela to the lumen as the base SI unit, it
is highly recommended to maintain the status quo.” The participants at the workshop agreed with
this recommendation. Other topics were the status of the mise en pratique of the candela and of the
Principles Governing Photometry. Work on both documents is well advanced and it is planned to
have final versions for the CCPR meeting in 2014.
L1-3
Liaison:
ISO/TC6/W3: Paper, Board and Pulp -Optical Properties
Joanne Zwinkels
The following recent activities of ISO TC6 WG3 (Optical properties), may be of interest to CIE D1:

Two ISO TC6 standards on whiteness measurement are currently being balloted as CDs (closing
date: Feb. 4, 2014). These CDs are: ISO 11476 Paper and board – Determination of CIE
whiteness, C/2° (indoor illumination conditions) and ISO 11475 Paper and board –
Determination of CIE whiteness, D65/10° (outdoor daylight). In response to Resolution 5 at the
TC6 plenary meeting in Montreal 2012, these two standards were amended to allow for
calculations using ASTM E309 for instruments that have bandpass correction (Tables 5) and still
maintain the non-bandpass correction procedure (Tables 6). This amendment provides the
ability to measure whiteness on a wider range of instruments.

Minor (editorial) revisions have been made to two TC6 standards on colour measurements:
ISO 5631-2 Paper and board – Determination of colour by diffuse reflectance – Part 2: Outdoor
daylight conditions (D65/ 10 degrees) and ISO 5631-3 Paper and board – Determination of
colour by diffuse reflectance – Part 3: Indoor illumination conditions (D50/2 degrees). This was
in response to comments received from systematic review of these Standards in 2012 and
conclusions by the members attending the WG3 meeting in Montreal 2012. These editorial
changes clarified the scope and differences in the experimental procedures between these TC6
Standards and related ISO standards for the measurement of the colour of paper used in the
graphics arts industry.

An FDIS version of ISO 2469 Paper, board and pulp – Measurement of diffuse radiance factor
(diffuse reflectance factor) –was prepared, after resolving comments from its 2nd DIS ballot. In
particular, clarifications were made to the use of working standards and control plates for
instrument calibration and validation and on the computation procedure described in Annex A,
specifically, the application of the 3-point convolution equation given here. Because of the
second DIS ballot for this project, a request was made to extend by 8 months the next stage
deadlines for this project.

ISO 4094: 2005 Paper, board and pulps – International calibration of testing apparatus –
Nomination and appointment of standardizing and authorized laboratories is undergoing
systematic review (closing date: March 17, 2014). In anticipation of ballot comments to revise
this Standard, pro-active measures have been taken. These include the preparation of a
revised draft version of ISO 4094 that addresses concerns from CASCO on conformity
assessment, and the creation of a new “scheme committee” that will oversee the optical
measurements calibration system of authorized laboratories that meet the requirements of both
ISO 4094 and the scheme committee procedures (to be defined and regularly reviewed). The
membership of this scheme committee has been established and includes individuals
representing all interested parties: producers, manufacturers, research, government, users. The
scheme committee will have its first face-to-face meeting during ISO TC6 week in Delft 2014.
39

ISO 8254-1:2009 Paper and board – Measurement of specular gloss – Part 1: 75 degree gloss
with a converging beam, TAPPI method, is undergoing systematic review (closing date: June
16, 2014). This method relies on gloss standards whose reflected flux distribution is known and
ideally similar to the samples under test. In practice, this is difficult to achieve.

The Ad hoc group on the Measurement and Characterization of Nanocellulose (AHG1), under the
chairmanship of Dr. Lyne Cormier, (Canada) and comprised of 34 experts from 12 countries, has
prepared a report to ISO TC6 which: 1) provides a framework for the development of
International Standards on the Measurement and Characterization of Nanocellulose; and 2)
makes a recommendation to TC6 on future actions, notably for TC6 to expands its scope to
include cellulosic nanomaterials and to form a new working group in this area.

The next Working Group meetings and Plenary meeting of ISO TC6 is in Delft, Netherlands, April
7-11, 2014. This will be preceded by a two-day meeting of the representatives of the optical
properties authorized laboratories (Opal Group).

Dr. Lyne Cormier, who manages the optical laboratory at FPInnovations (Canada) has been
approved as the new Chair of ISO TC6 for a one year period starting January 1, 2014; she
succeeds Dr. Byron Jordan who has served as TC6 Chair for the past 6 years.
Respectfully submitted,
Joanne Zwinkels
National Research Council of Canada
L1-4
Liaison:
ISO/TC38/SC1: Textiles: Colour Fastness & Measurement
M Ronnier Luo
No report.
L1-5
Liaison:
ISO/TC42: Photography
Klaus Richter
No report.
L1-6
Liaison:
ISO/TC130: Graphic Technology
Danny Rich
ISO TC 130 held its fall meeting at Crown Plaza Hotel, Chicago, USA 30 September to 6 October 2012.
The fall meeting includes the plenary session and I have included relevant actions from TC 130 in this
report.
The following were topics of discussion carried over from the spring meetings that are still open.
1. ISO TC 130 has not received guidance from the CIE on how to move forward from the older CIE
recommendations of CIELAB and CIE94 to adoption of CIEDE2000. It was reported 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 a
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. The
Technical Committee and the graphic engineering community waits further guidance and
40
clarification from the CIE.
2. 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. When characterizing materials that are luminescent it is possible to obtain CIELAB L*
values greater than 100. But there is no guidance as to the relevance of these values, since the
CIE Publication 15:2004 defines the range of L* as 0 to 100. Would CIE Division 1 be willing to
provide some guidance as to the applicability to the power function of Y for Y values greater than
100?
3. Standards ISO 12646 and ISO 14861, the standards that documents the processes for calibrating
self-luminous displays for simulating the proof of a print job using flat panel displays, have
moved forward and should be balloted for release as a draft international standard in 2013.
4. As in the last liaison report, the lack of progress in CIE TC 1-69 continues to give reason for some
concern on the part of image reproduction industry, especially in the packaging industry where
the value of the brand and the decision by the consumer to purchase or not to purchase is
strongly linked to the color rendition of the package on the shelf. Now that many countries
around the world have legislated against energy inefficient incandescent lamps and are
beginning to take a similar stand on mercury containing fluorescent lamps, we are starting to see
commercial product offerings of high luminous output linear LED arrays that are intended to
replace tubular fluorescent lamps. These produce very, energy efficient commercial lamp light
but introduce unpredictable and often undesirable color effects on print, especially if the print
substrate contains fluorescent whitening agents.
At the plenary, it was reported that the DIN wishes to relinquish the role of Secretariat of ISO TC
130. After some negotiation, China has agreed to establish a new secretariat under the direction of
the Standardization Administration of the Peoples Republic of China (SAC). However, TC 130 WG 3 –
Process Control and WG 4 – Materials will continue utilize DIN as their secretariat. No other actions
or activities were planned or carried out that are of interest to CIE Division 1.
Respectfully submitted,
Dr. Danny C. Rich
L1-7
Liaison:
ISO/IEC JTC1/SC28 Office Equipment
Klaus Richter
ISO/IEC JTC1 SC28 "Office equipment" is mainly a hardware oriented ISO/IEC joint standard
committee.
Under ballot and under the header "Information technology - Office equipment" (Jan. 2014) are
together with colour test charts:
 ISO/IEC DIS 24711, Method for the determination of ink cartridge yield for colour inkjet printers
and multi-function devices that contain printer components
 ISO/IEC DIS 29102, Method for the determination of ink cartridge photo yield for colour printing
with inkjet printers and multi-function devices that contain inkjet printer components
 ISO/IEC DIS 24711, Method for the determination of ink cartridge yield for colour inkjet printers
and multi-function devices that contain printer components
A working Group WG4 "Image quality” is leaded by Eric Zeise, and is very active. Image quality
attributes like "Mottle", "Graininess", and many others are specified visually and by measurement in
ISO/IEC TS 24790 and ISO/IEC TS 24790. The present work will lead to International Standards (IS)
41
instead of Technical Specifications (TS). This work is a joint work with ISO TC130 and also ISO TC42
likes to join.
A working Group WG5 "Office Colour" is leaded by Fumio Nakaya with the following Scope: WG5 will
develop standard documents to enhance the interoperability of colour data for exchange among
office colour equipment and will develop standard documents that evaluate colour properties for
office colour equipment systems. WG5 will work jointly with the appropriate standards organizations
to address these issues in both new standards and revisions of existing standards as necessary.
In the following list of New Work Items (NWI) with a Priority, which is based on field studies of 2009,
some names have changed during recent years. The DIS vote on CD 17823 failed in 2014 (NWI 00).
One proposal was to make a TR instead of an IS. One conflict is with terms of the so-called RGB
printers (which have "RGB primaries" and work in reality with "CMYK primaries"). No other work of
the list has started up to now (January 2014).
NWI
00
01
02
03
04
12
07
09
10
06
08
05
13
11
Priority
02
05
06
11
09
10
07
12
00
03
13
04
09
01
Status
CD17823
2014?
Change
2015?
2015?
2015?
Change
-
Present Title
Colour terminology for office colour equipment (DIS failed, 2014)
Automatic identification using cloud technology
Monitor and digital projector colour metadata, now NWI no. 01
Computer display and digital projector colour test method
Measurement and Control of Colour Characteristics in Printers
Colour repeatability test method
Office reference print gamut - RGB encoding
Colour space standards for offices
Test method of colour gamut mapping algorithm for colour printer
Office viewing environments - user interface chromatic adaptation
Camera raw image rendering standards for office printers
Automated selection of colour print conditions, now NWI no. 01
Office color management workflow for digital color documents
Specification of named color in office document
The SC28 resolution 18/2009 of Busan includes the statement "SC28 welcomes a new proposal in
the future based on CIE human visual RGB work, potentially in relation to NWI 13 "Office Colour ...".
For the complete SC28 resolution and additional information, see the "CIE Division 8 Meeting
Minutes of December 2013", section "Liaison Report CIE Division 8 to ISO/IEC SC28" on the CIE
Division 8 web site.
The next SC28 Plenary meeting is scheduled in June 2014 in Berlin. Germany may propose action of
SC28 and try to reach consensus based on the DIN standard series DIN 33872-1 to -6:2010 "Method
for the specification of relative colour reproduction with Yes/No criteria." For the relation of these
and other standards, which are all based on equally spaced output (and input) by CIELAB
colorimetry, see http://130.149.60.45/~farbmetrik/SE20/SE200-7N.PDF.
42
Fig. 1 shows how to realize the user wishes of DIN 33872-X, for example to produce equally spaced
output in CIELAB, based on corresponding equally spaced rgb data in the file.
Remark: There are different sources of ISO/IEC test chart on the market, for example according to
ISO/IEC 15775 Amendment 1:2005 with digital and hardcopy test charts from the Japan Association
JBMIA. The following URL shows this (see JS X 6933) and the relation to other standard documents
http://130.149.60.45/~farbmetrik/SE20/SE200-7N.PDF.
All these standard documents are based on equally spaced output (and input) by CIELAB colorimetry
and on corresponding equally spaced rgb data in the files.
Fig. 1 includes the application of the two Reportership Reports CIE R1-47 Hue Angles of Elementary
Colours, and CIE R1-57 Border Between Luminous and Blackish Colours, which can be freely
downloaded from the CIE Division 1 web site. In addition Fig. 1 includes some more URL's for free
download of further information.
Up to now on the CIE Division 8 website there is only a summary of the Reportership Report CIE
TC8-09: "Output Linearization Methods for Displays and Printers" with the following Terms of
Reference: "Make a report on proposals for the application of output linearization methods. The
report may cover the device and elementary hue output of displays and printers." The publication of
the full report (38 pages, 1MB) is expected after a positive CIE vote in CIE Division 8.
Fig. 1 shows the value of the three CIE Reporterships for the realization of the user wishes, for
example "Equally spaced output in CIELAB" and "Device independent elementary hue output". If the
device companies have no solution to realize the user wishes as an option, then "linearization
companies" may fill this gap by appropriate software, and in addition for different output paper, and
8 values of display reflection according to ISO 9241-306 "Visual display requirements". Fig. 1 includes
some advantages. There is only one output solution. A transfer table of rgb data to new rgb or cmyk
data (complete undercolour removal) is calculated, based on CIE output measurement of the
43
standard test chart with 1080 colours, see CIE R8-09.
The application area of Fig. 1 goes far beyond the limited scope of SC28. Also experts of CIE Division
1 "Vision and Colour" and CIE Division 8 "Image Technology", ISO TC159 "Ergonomics", TC 130
"Graphic Arts", TC 42 "Photography", TC 171 "Document Management", and others have shown
interest for the application of the new "device-independent" hue output, and the definition of a
device-independent RGB* colour space for input, storage, transfer, and output.
L1-8
Liaison:
IALA (International Association of Lighthouse Authorities)
Malcolm Nicholson
No report.
L1-9
Liaison:
ISO/TC159: Ergonomics
Ken Sagawa
No report.
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