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COMMISSION INTERNATIONALE DE L'ECLAIRAGE INTERNATIONAL COMMISSION ON ILLUMINATION INTERNATIONALE BELEUCHTUNGSKOMMISSION

DIVISION 1: VISION AND COLOUR

MINUTES of the 3rd Meeting of the Kwak Term

Saturday 28th April 2018

CPC Building, Taipei, Taiwan

Some of the delegates after the CIE Division 1 meeting

1. WELCOME The Division Director, Youngshin Kwak, welcomed all those present to the Division 1 meeting that formed part of the CIE Topical Conference in Taipei, Taiwan.

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2. ATTENDENCE Officers Youngshin Kwak KR DD – Director Nana Itoh JP AD – Vision Ellen Carter US AD – Colour Peter Hanselaer BE DE – Editor Li-Chen Ou TW DS – Secretary

Country Belgium BE Li-Chen Ou* Representatives Canada CA Ellen Carter* France FR Li-Chen Ou* Germany DE Jan Henrik Wold* Hong Kong HK Minchen Wei Hungary HU Li-Chen Ou* Japan JP Yoko Mizokami Korea KR Youngshin Kwak* Norway NO Jan Henrik Wold Netherlands NL Kees Teunissen South Africa ZA Edwin Mofokeng* Spain ES Li-Chen Ou* Taiwan TW Tsung-Hsun Yang Turkey TR Li-Chen Ou* USA US Ellen Carter *Nominated representative

Thus there were 15 countries represented at the meeting for official ballots. Technical Nana Itoh TC1-84 Committee Ellen Carter TC1-85 Chairmen Li-Chen Ou TC1-86 Po-Chieh Hung TC1-89 Ming Ronnier Luo TC1-96 Jan Henrik Wold TC1-97 Reporters Youngshin Kwak R1-67 Kees Teunissen R1-68 Yoshi Ohno R1-68 Shao-Tang Hung R1-69 Guests In addition, there were 13 guests present.

Total attendance: 26 persons 3. MEMBERSHIP The following change in national representative to Division 1 was noted: Greece: Georgios Paissidis was the new national representative. 4. CONFIRMATION OF THE AGENDA The Agenda, as appended to the Minutes, was agreed.

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5. MINUTES The Minutes of the 2017 meeting held at Jeju, South Korea were approved with correction of TC1-91 title. Division ballot result: 15 in favour. 6. MATTERS ARISING FROM THESE MINUTES There were no matters arising not covered by items on the agenda. 7. DIVISION OFFICER REPORTS

7.1 Director’s Report

The Director presented a report and highlighted the following points from the activities over the last year: Terms of Reference To study visual responses to light and to establish standards of response functions, models and procedures of specification relevant to photometry, colorimetry, colour rendering, visual performance and visual assessment of light and lighting. Officers

Director Youngshin Kwak (KR) Associate Director (Colour) Ellen Carter (US) Associate Director (Vision): Nana Itoh (JP) Editor: Peter Hanselaer (BE) Secretary: Li-Chen Ou (TW)

Recent Publications: • CIE 228:2018 Grey-Scale Calculation for Self-Luminous Devices

D1 Status: • 14 Technical Committees (5 Vision + 9 Colour) • 6 Joint TC • 11 Reporterships • 1 Research Forum

New Interorganizational Joint Technical Committee Proposal: • ISO has issued a vote to form a new JWG4 on Integrative Lighting in ISO TC274. It is proposed that

this is also a JTC within CIE with Division 6 as the lead. • D1 will join this JTC. 7.2 Editor’s Report

2017:

• Oct 29, Meeting with Peter Zwick (role of a D-editor) • Nov 13, Draft TN DR1-68 “A colour gamut measure and colour-shift information based on CIE

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13.3-1995” (R: K. Teunissen NL, Y. Ohno US and K Mukai JP) edited and sent to Peter Zwick • Dec 26, First call for input to TC chairs, reporters and liasons regarding the Activity Report 2017

2018:

• Jan 11, Reminder input Activity Report 2017 • Mar 19, First draft of D1 activity report 2017 was sent to D1 officers • Mar 22, Second draft of D1 activity report 2017 sent to D1 officers • Mar 25, Draft TR TC1-76 “Unique hue data” (TCC Sophie Wuerger/Renzo Shamey) edited second

time • Apr 07, Review of the CD TC 1-89 “Enhancement of Images for Colour Defective Observers”

7.3 Secretary’s Report • D1 country member changes: 1 Greece: Georgios Paissidis • DR closed: 1 (R1-65, Taiichro Ishida) • New JTC: 2 (JTC10, JTC12) • New DR: 1 (R1-69, Shao-Tang Hung)

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8. TECHNICAL REPORTS – VISION: Nana Itoh

TC1-83 Visual Aspects of Time-modulated Lighting Systems: Dragan Sekulovski NL There was no TC meeting in Taipei. • WD of TR is in preparation. TC1-84 Definition of Visual Field for Conspicuity: Nana Itoh JP There was no TC meeting in Taipei. TCC reports current situation in DV 1meeting. • TCC is now revising WD according to the discussion of TCM held in Jeju. • After the revision, WD will be circulated within TC members. [Request for Division 1 – extension to2019 of TC activity:] The TC was approved by D1 to extend its activity to 2019, with the following ballot results: Against: 0 Abstention: 0 In favour: 15 TC1-88 Scene Brightness Estimation: Yoshiki Nakamura JP There was no TC meeting in Taipei According to TCC (by mail), it is hard to continue TC activity because of the lack of time and not enough data for contents yet. Since it is already passed 4 years, D1 decided to close TC, and ask TCC to consider any possibility to continue this work in other way, e.g. propose new TC. [Request for Division 1 – close TC activity:] TC1-88 was closed. Against: 0 In favour: 11 Abstention: 4 TC1-89 Enhancement of Images for Colour Defective Observers: Po-Chieh Hung US There was no TC meeting in Taipei. TCC report current situation in D1 meeting. • WD was approved as CD on Feb. 11, 2018. • CD was reviewed by DE on Apr. 16, and is in revision process. TC1-93 Calculation of Self-luminous Neutral Scale: Robert Carter US • New technical report was published in 2018. “CIE 228:2018 Grey-Scale Calculation for Self-Luminous Devices” • TC1-93 was closed. TC1-97 Age- and Field-Size-Parameterized Calculation of Cone-Fundamental-Based Spectral Tristimulus Values: Jan Henrik Wold NO A TC meeting was held in Taipei. • New beta version released for testing, including an installer for PC, an installer for Mac, and

Source code for Linus users. • New beta version can be downloaded from following URL. https://github.com/ifarup/ciefunctions/releases • TCC asked D1 members to check this beta version and ask feedbacks if any. R1-66 The Effect of Dynamic and Stereo Visual Images on Human Health: Hiroyasu Ujike JP • Report is now being finalized, and will be submitted when it is completed. • Reporter hopes the report possibly encourages further exploration on the issues, at the time of

innovative imaging technologies.

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JTC 1 (D1/D2/D4/D5): Implementation of CIE 191:2010 Mesopic Photometry in Outdoor Lighting There was no TC meeting in Taipei • Webex meeting was held in Feb.3rd and May 2nd. • Physical meeting will be held in end of May conjunction with CIE Workshop in Berlin. • WD of TR is in preparation. JTC 7 (D1/D3): Discomfort caused by glare from luminaires with a non-uniform source luminance There was no TC meeting in Taipei • According to Co-Chair, TC ballot was in Jan.2017 and WD is currently being modified. JTC 9 (D1/D2/D3/D6): CIE system for metrology of IPRGC influenced light response (new title) There was no TC meeting in Taipei • According to TCC (by mail), followings are current situation and activities of JTC. • Title of this JCT was changed. • TC ballot was carried out by Nov.2017 • BA decided to have a shortened approval process for this project. • BA/DIV ballot on the ED/IS was carried out by Feb.2017. • Expected publication of CIE/ISO standard in Q4 2018. In the D1 meeting, how D1 officially respond to the content of JTC9 draft were discussed. D1 decided to take the following actions: 1. Ask JTC9 to make clear statement in DIS draft about values of the tables applicable only for

non-visual effects, and not for the colourimetry. This request will be report to TCC of JTC9 in the BA meeting.

2. D1 Co-chair will ask JTC9 to send DIS draft to circulate within D1 before next ballot.

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9. TECHNICAL REPORTS – COLOUR: Ellen Carter Technical Committees

TC1-63 Validity of the Range of CIEDE2000 (Klaus Richter, DE) No meeting was held in Taipei this year. Richter sent a report that the members have decided to proceed with this report after the TC1-81 TR has been published. For the progress see the TC1-81 report. Discussion: Since the TC members had decided to defer further work until after the TC1.81 report was published, and since the TC was formed in 2004 thus both the Chair and the TC have exceeded the current Code of Procedures time limits of a maximum of 8 years, it was thought that the best resolution was to vote to close the TC at this time. Then after the publication of the TC 1.81 TR report, it would be possible to reactivate the work of the TC as a new TC which would then have a new time clock starting with the TC’s formation. Vote to close yielded the following results: In favour:11; Abstention: 3; and Against: 1.

TC1-76 Unique Hue Data (Sophie Wuerger GB, co-chair Renzo Shamey US) Peter Hanselaer completed a second editing of the TR March 25th. Currently the responses to this editing are being completed and soon the TR will be sent to CB. Question: Should we vote to extend this TC to 2019 to allow time to complete the publication process. This was not voted at the meeting but should happen very soon.

TC1-81 Validity of Formulae for Predicting Small Colour Differences (Klaus Richter, DE) This TC did not meet in Taipei, but the TC members have been working on the TR. Richter sent a report stating: The Technical content of the last CD seems well described within the last report of the CIE D1 Jeju meeting. During the meeting in Jeju, together with the CIE CB, the TM expected that the TCM vote and the Enquiry Draft may be completed by the end of April 2018. However, one member was again asked about comments on the CD available in Jeju. The response took until February 2018. After new careful comment solutions, a one-month TCM vote has started and will end at April 24, 2018. It depends on the TCM comments and the possible solutions, especially of the Annex B, how and when the TC1-81 report may proceed.” Discussion: At this meeting it appeared that the CD may proceed soon toward publication in the near future.

TC1-85 Update CIE Publication 15:2004 Colorimetry (Schanda, HU/Carter, US) Carter reported what has happened since the Jeju Meeting: 1) The TC received the CD from the CB and section authors worked diligently to reach agreement on the remaining questions; 2) The final document was returned to CB on March 1, 2018; 3) after a teleconference resolving remaining questions, the Chair received the ED from CB; and 4) March 19, 2018 the ED was sent to TC members and country delegates for comment with the comment period closing May 19, 2018. The future steps include resolving any comments that arise during the comment period. Then CB will conduct the balloting of the document and finally publication of CIE 15:2018.

TC1-86 Models of Colour Emotion and Harmony (Li-Chen Ou, TW) A technical meeting was held on 27th October 2017, Jeju. A key paper related to the TC work was submitted in late 2017 to Color Research and Application and was accepted in April 2018. Next step is to finish the WD stage.

TC1-91 New Methods for Evaluating the Colour Quality of White-Light Sources (Yadan Lin, CN) A short meeting was held this morning run with Minchen Wei standing in Yandan Lin, who was not able to attend because of delayed travel documents. The TC agreed to ask Division 1 to change the word “recommending” to “introducing” in the TOR. This was approved by ballot. The vote to change TOR from “recommending” to “introducing” had the following result: In favour: 13, Abstain: 2.

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The Chair sent the following summary of TC1.91 status (by 25 April. 2018) • Draft report V4.0: include indexes, CQS, FCI, MCRI, PS and IES Rg, Relative gamut area index

(Ga), Colour rendering vectors and colour saturation icon • Response: One replied with comments (15 pages). • Draft report V4.1: All comments to DR 4.0 has been included and sent out for new comments. • Draft report V5.0：All updated contributions to DR 4.1 were added and sent out before Jeju

meeting in 2017. • Draft report V5.5: Contributions and comments to DR5.0 were sent to all members on April

11, 2018. Little editing problems were mentioned and will be updated. No more comments were received, except one member mentioned that after Taiwan meeting he will check the version.

• Next steps to ask for approval of the change of the ToR as highlighted in first slide • If no new input, then vote in the TC.

TC1-92 Skin colour database (Kaida Xiao, GB) A TC Meeting was held this morning, but then the Chair had to leave before the Division 1 Main meeting. However he sent the following report:

• New skin data study was conducted in Leeds (British women, 300 subjects, 4 ethnic groups, Spectrophotometer measurement, and Facial image system)

• Uncertainty of skin colour measurement: Spectrophotometer, TSR, SP vs. TSR; Spot measurement vs. Image Measurement

The work plan includes preparing the TR and identifying further work. A vote was taken to extend this TC and Chair to 2020, with the following result: In favour: 15. TC1-95 The Validity of the CIE Whiteness and Tint Equations (Robert Hirschler, HU) This TC did not meet but the chair sent a report on the recent committee work being carried out, including 8 published articles. The TC work is divided into two phases: 1) whiteness perception which is well under way; and 2) whiteness magnitude, which will start soon. Future activities in order to comply with the ToR of the TC more research should be focused on whiteness formulae for non-D65 illuminants and sets of whiteness samples shall be made available for TC members to conduct comparable research on the visual vs. instrumental evaluation of whiteness. The details of the report sent include: 1) A list of studies published by Wei, Luo et al.:

• S. N. Ma, M Wei, J. Liang, B. Wang, Y. Chen, M. R. Pointer and M. R. Luo, (2016) Evaluation of whiteness metrics, Light. Res and Tech. DOI: 10.1177/1477153516667642.

• M. Wei, S. N. Ma, Y. Wang, M. R. Luo. Evaluation of whiteness formulas for FWA and non-FWA whites. Journal of the Optical Society of Am. A. 2017 Apr 1;34(4):640-647.

• M. Wei, Y. Wang, S. Ma and M. R. Luo, Chromaticity and characterization of whiteness for surface colors, Optic Express, in progress.

• S. Ma, M. Wei, J. Liang, B. Wang, M. R. Pointer and M. R. Luo, Evaluation of whiteness indices, CIE2016 conference, Melbourne, CIE 2016 Proceedings, pp112-117.

• S. N. Ma, J. Liang, M. Wei and M. R. Luo, Extension of CIE whiteness metric under different • illuminants, 24th Color Imaging Conference, 7-11 November, 2016 San Diego USA, 198-202. • M. Wei, S. N. Ma, M. R. Luo, The necessity of a whiteness scale for FWA-enhanced whites,

24th Color Imaging Conference, 7-11 November, 2016 San Diego USA, 237-241. • Y. Z. Wangle, M. C. Wei and M. R. Luo, (2017) Whiteness boundary for surface colors, 25th

Color Imaging Conference, Lillihammer, Norway, 98-102.

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2) Wei, Luo et al. Phase 1 study - White Perception: Experiment for assessing white perception

• To apply Spectrum Tuneable LED system (STLS) to perform experiment including 3 UV LEDs to perform experiments under different CCTs and UV levels

• To assess whiteness in terms of white+hue %, white/not white, etc. • Testing and developing new whiteness indices, 1) standard D65/10 CIE-W, 2) varying source

CIE-W(xn,yn), 3) CIE-WCAT02, 4) CIE-WOptimised， • Realize different whiteness scales are required for FWA and nFWA samples • FWA: 1) CIE-WCAT02, 2) CIE-WOptimised， • nFWA: Depth-Berns and Saturation-Cho et al • -5>T>5, which is larger than the current -4<T<2. The new experiment further verified this

using 105 samples. • White boundary for different CCTs at different UV levels in terms of ellipsoids in xy and

CAM02-UCS were established. 3) Works in preparation / in progress

• Katayama, Ichiro: Visual evaluation results of whiteness under the illuminant D50 condition and their predictions (CIE)

• Luo, Ronnier and Wei, Minchen: Evaluation of Whiteness Formulas for FWA and Non-FWA Whites (Presented at AIC)

• Luo, Ronnier and Wei, Minchen: Characterization of whiteness appearance for FWA-enhanced white (AIC)

• Vik, Michal: Development of whiteness formula based on CIECAM02 (CIE) • Wei, Minchen: A proposal for characterizing surface whiteness under an arbitrary light source

(CIE) 4) Wei, Luo et al. Phase 2 study – Whiteness magnitude Phase 2 to start soon

• To study the whiteness magnitude under different illuminants at different UV levels • Data accumulation • Testing metrics • Developing metrics

5) Future activities • In order to comply with the ToR of the TC more research should be focused on whiteness

formulae for non-D65 illuminants • Sets of whiteness samples shall be made available for TC members to be able to conduct

comparable research on the visual vs. instrumental evaluation of whiteness

TC1-96 A comprehensive model of colour vision (M. Ronnier Luo, CN) This TC met this morning. Recent publications relating to this TC include: CCAM - S. T. Wei, M. R. Luo, K. Xiao and M. R. Pointer, A comprehensive model of colour appearance

for related and unrelated 42(2017)293-304. CAT16, CAM16, CAM16-UCS - C. J. Li. Z. Li, Z. Wang, Y. Xu, M. R. Luo, G. H. Cui, M. Melgosa, M. H. Brill,

and M. R. Pointer, Comprehensive color solutions, CAM16, CAT16 and CAM16-UCS, Col., Res. and Appl., 42(2017)703-718.

CAM15u, CAM16uz - Withouck M, Smet K A G, Ryckaert W R, Hanselaer P. Experimental driven modelling of the

color appearance of unrelated self-luminous stimuli: CAM15u. Optics express, 2015, 23(9):

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12045-12064. - W. Huang and M. R. Luo, Verification of CAM15u colour appearance model and the QUGR

glare model，Light. Res and Tech. doi.org/10.1177/1477153517734402. Jzazbz and Jzazbz-CAM

- M. Safdar, G. Cui, Y. J. Kim and M. R. Luo, Perceptually uniform color space for image signals including high dynamic range and wide gamut, Optics Express, 25(2017)15131-15151.

CAT - Smet KA, Zhai Q, Luo MR, Hanselaer P. Study of chromatic adaptation using memory color

matches, Part I: neutral illuminants. Optics Express. 2017 25(7):7732-48. - Smet KA, Zhai Q, Luo MR, Hanselaer P. Study of chromatic adaptation using memory color

matches, Part II: colored illuminants. Optics Express. 2017 25(7):8350-8365. - Huang H. P., M. Wei, L. C. Ou, White appearance of tablet display under different ambient

lighting conditions, Optics Express, 26(2018)5018-5030. - Q. Zhai and M. R. Luo, Study of chromatic adaptation via neutral white matches, Optics

Express, 26(2018)7724-7739

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Leeds data – Dr. Chenyang Fu

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Progress: Completion of Data collection in 2016

• C. Fu’s PhD data (Unrelated colours under photopic and mesopic regions) • K. Xiao’s PhD data (Same colours under 6 different sizes)

Large progress has been made since 2017 in the areas of CAT, CAM and UCS (see publications). TC seminars

• First: 8 September, 2016, Prague • Second: 28 April, 2018, Taipei

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Change of Strategy 1. To be focused on CAT16, CAM16, CAM16-UCS, not based on CAT02, CIECAM02, CAM02-UCS, 2. To include new 3rd dimensional colour scales: Vividness, Saturation, Blackness, Whiteness

Work Plan 1. To complete the remaining work on CAM16 extension to unrelated colours by the end of July, 2. To circulate the 1st report by the end of 2019, and 3. To complete the TC in June 2020.

Thus at this meeting the vote to extend TC1-96 to extend to 2020 was taken with the following result: In favour: 15. Joint Technical Committees JTC 8 Terminology in light and lighting (Div. 1 members Sharon McFadden, CA & Michael Pointer, GB) There was no report at this meeting. JTC 10 A new colour appearance model for colour management systems: CIECAM16 (Changjun Li CN of D8; M. Ronnier Luo GB of D1) Dr. Li sent his regrets and a report that stated the following. This TC had an open meeting in Jeju Island, Korea during CIE meeting in October 2017. The draft TR was available in Sept 2017 and the draft TR was distributed to all members of the TC and hopefully, the final draft TR will be completed by the end of 2018. Work Plan has the aim is to complete the TR publication process and close the JTC by the end of 2019, if not earlier. JTC 12 The measurement of sparkle and graininess (A Ferrero ES of D2; Y Kwak KR of D1) Ferrero sent the following update Progress (text added to the draft since the last report): • Section 1, “Introduction”: Untouched. Daniel Schier claimed to lead the subsection “Pigments” • Section 2, “A theoretical framework”: 4 pages. A proposal of text for all subsections, except 2.3 “Visual considerations: the role of the surround”. The text for this subsection 2.3 was included in section 3, but it must be discussed the adequate place yet. • Section 3: “Spectrophotometric measurements”: 15 pages. A proposal of text for all subsections, except 3.1.7 “Recommendations on geometries”. • Section 4: “Visual sparkle and graininess”. Untouched. • Section 5: “Measurement scales”. Untouched. • Glossary of terms: Around 20 terms were identified to be properly defined, and some definitions were copied from literature. A discussion forum was created in CIE collaboration tool about the definition of sparkle. Others discussion fora will follow. Reporterships R1-53 Gloss perception and measurement (Frédéric Leloup, BE) Leloup submitted his final report in early 2018. In this report he proposed formation of a TC (see new TC proposals below), and also asked about whether the report should be a TN. Unfortunately, this Reportership was formed before the rule was made that if a reportership was to produce a TN it had to be in the TOR for the reportership. He also requested that the reportership be closed with the completion of his report. During discussion at this main E12 meeting it was suggested that the most efficient way to proceed was to open the TC and then one of the first acts of the TC could be to publish a TN from the results of the reportership report on the way to completion of the rest of the goals of new TC. Therefore, it was voted to accept the reporter’s report and close the reportership, with the thanks of the Division. Vote to close R1-53: In favour: 15.

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R1-58 Liaison with ISO TC130 Graphic Technology (Phil Green, GB) This reportership was opened in 2012 and was very active for the first few years culminating in a symposium. However, the last couple of years it has been inactive. In Jeju Carter suggested the possibility of closing the Reportership, but no vote was taken. After the meeting Carter also wrote to Green suggesting closure of the reportership but got no response. With no response this year Carter requested a vote to close the reportership, which passed with 14 in favour and 1 abstention. R1-60 Future colour-difference evaluation (Guihua Cui, CN) This reportership was opened in 2013 and has routinely sent updates on publications in the area of colour-difference evaluation. However, there was no report this year. Discussion at this meeting suggested it should remain open to continue watching for new publications, especially since some new ideas were likely to be being published soon. R1-61 Source Whiteness Metric (Aurelian David, US) This reportership was opened in 2014. However, since that time we have never received an update or report. In Jeju Carter suggested the possibility of closing the Reportership, but no vote was taken. After the meeting Carter also wrote to the reporter about closing the reportership but got no response. With no response this year Carter requested a vote to close the reportership, which passed with the following vote tally In favour: 15 to close. R1-62 Typical LED Spectra (Sophie Jost, FR) Jost submitted this report: Typical LED Spectra

• Measurements from SSL products • Autumn 2016 • 1298 SPDs of white LED sources available on the market • Traceable measurements • Database • Relative spectral measurements • Typical White LED • 380 nm to 780 nm with 1 nm steps • Sorting of the data • CCTs • Spectral shapes • Analysis • Normalisation • Determination of a closeness score • Determination of a centroid SPD • Determination of a representative SPD • Determination of a representative illuminant • Representative illuminants for B-LEDs

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Representative illuminants for Blue Hybrid LEDs

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• Not representative illuminants but typical spectral shapes (RGB and Violet LEDs)

Update of CIE 15 (TC1-85)

Publications • Jost, S., Ngo, M., Ferrero, A., Poikonen, T., Pulli, T., Thorseth, A., AND Blattner, P. (2017)

« Determination of illuminants representing typical white light emitting diodes sources » CIE 2017, Midterm Meeting, Jeju Island, Republic of Korea.

• Kokka, A.; Poikonen, T.; Blattner, P.; Jost, S.; Ferrero, A.; Pulli, T.; Ngo, M.; Thorseth, A.; Gerloff, T.; Dekker, P.; Stuker, F.; Klej, A.; Ludwig, K.; Schneider, M.; Reiners, T.; Ikonen, E.

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“Development of LED illuminants and reference spectrum for colorimetry and photometry" Under submission.

Although the reportership has completed its work, we are going to leave it open until the update of Publ. 15 on Colorimetry is published, in case there are any questions on the LEDs provided from this reportership to TC 1.85. Sophie also has submitted the LED data in both 5 nm and 1 nm intervals and normalized to 1000 lux. R1.63 Tristimulus Integration (Changjun Li, CN) Li sent a report that there was no new work in this reportership this year. R1.64 Real Colour Gamuts (Changjun Li, CN) Li sent a report that there was no new work in this reportership this year. R1.67 Revisiting Correlated Colour Temperature (Youngshin Kwak, KR) – Research Forum is proposed based on this reportership. (See new research forum proposal). R1.68 A gamut area measure and colour-shift graphic, based on CIE 13.3-1995R1.67 (Kees Teunissen, NL) Officially started: 18 April 2017 Draft TN versions: 10 Status: Enquiry Draft Technical Note (ED/TN) was circulated on Jan 09, 2018 for BA and D1 commenting. Document with compilation of comments was received Feb 12, 2018. March 12, 2018: Responses to the comments have been drafted and provided to D1 management. April 27, 2018: Meeting with D1 management how to proceed Based on the comments received, it was decided to simplify the document and publish the TN in support of the Excel calculation tool that can replace the old CIE DOS-based tool. It is well-known that fidelity alone is not enough to characterize differences in colour appearance between white-light sources. Therefore, as long as Ra is still in use, a colour gamut index, colour shift graphic and objective information on the direction of the colour shifts for the individual TCS can provide useful information to the user, in addition to Ra. A new ED/TN will be circulated for BA and D1 commenting. R1.69 Applicability of Metrics for Evaluating Reflected Glare on Displays (Shao-Tang Hung, TW) No report at this meeting.

Research Forum

Research Forum 3 (Kees Teunissen, NL)

Established during the D1 meeting in Jeju: October 2017 Convener Teunissen reported: First meeting in Jeju on October 27, 2017 1. 12 attendees (9 countries) expressed their interest in becoming a member of the RF 2. Waiting for CIE Membership Form and collaboration space to invite CIE members to participate in the RF 3. Available on the CIE website under Research Fora 4. RF-03 was allocated to this Research Forum Meeting in Taipei on Saturday April 28 discussed the scope. 31 participants and 30 would like to participate in the RF.

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Proposal: 1. Change old approved title: “Identifying and carrying-out research needed for specifying perceptually relevant, colour-related, aspects of white-light sources” to “Matters relating to specifying colour rendition of white-light sources” 2. Refine scope, with D1 director, to provide a better (more concise) description of the intended aims of the RF, as previously agreed, to be published on the CIE Website. A vote was taken to change the title into “Matters relating to…” with the result of 15 in favour. 10. PROPOSALS OF NEW TECHNICAL COMMITTEES 1) From Minchen (Tommy) Wei Title: The Validity of the Chromatic Adaptation Transforms under

White Light – (if approved this TC would be in the Colour Section) a. Scope: Recent experimental work revealed the incomplete chromatic adaptation under

white light, especially those with low CCT and off-Planckian chromaticities, which are important to the performance of chromatic adaptation transforms. This was not considered in existing chromatic adaptation transforms (CATs). The TC will review the existing CATs and propose modifications by including a two-step transform to take the effect of white light chromaticity on degree of chromatic adaptation into consideration.

b. Initial Members (from at least five different countries): Fairchild, Mark (US); Li, Changjun (CN); Liu, Qiang (CN); Luo, Ronnier (GB); Royer, Michael (US; Sekulovski, Dragan (NL); Smet, Kevin (BE); Wei, Minchen (HK)and Yaguchi, Hirohisa (JP)

2) From JanHenrik Wold – Revision and Update of CIE 170 – (if approved this TC would be in the

Vision section) At the meeting Wold offered 3 options: 1) just revise CIE 170 report to have part 1 be consistent with part 2 and both be consistent with programed material; 2) also include extension of data from 360nm to 380 in printed tables, and from 30-830 in accompanying tables; 3) deal with the concavity of the spectral locus. Carter spoke in favour of adding option 2; someone else also spoke in favour of adding option 3.

3) From Frederick Leloup- Title: Gloss measurement and gloss perception - Definition and

standardization of visual cues to gloss. (if approved this TC would be in the Vision Section) Scope: In vision science, Estimation is the process of identifying and differentiating between similar materials. Estimation therefore tends to deal with metric differences between materials along one or more specific continuous parameters. The key questions for visual estimation of material properties are which these cues are that the visual system relies on, and how the visual system computes the material property from these identified cues.

a. With respect to surface gloss, it has been hypothesised that the human brain seems to rely on a set of properties of the proximal stimulus and on how these change for representing the typical appearance, irrespective of the physical basis. Typical examples are the number of highlights, their size, contrast and distinctness, etc.

b. From a metrological point of view the new scientific discoveries offer interesting opportunities. While a global description of visual gloss appraisal by aid of just one quantity seems questionable and might even be impossible, separate quantitative scales of established visual cues (such as the brightness of the specular highlight, the distinctness of the highlight, and its contrast) could be derived for dedicated sets of gloss artefacts, as they are psychophysically experienced under typical circumstances. For each scale, inter-observer variations could be evaluated (and minimised) in relation to the

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used assessment conditions (illumination and viewing conditions, but also assessment protocol). Which are the dedicated sets of specimens and the appropriate assessment conditions (type of illumination, illuminance level, viewing distance, etc.) to be used for the development of such new psychophysical scales, has to be investigated.

c. This TC has the purpose to publish a technical report; i. describing recommendations for standardised visual assessment conditions of

separate, established cues to surface gloss, ii. defining a standard gloss observer for each separate diagnostic cue,

iii. based on i and ii, suggesting optical methods and metrics for describing surface gloss in correlation with the separate, established gloss cues.

d. Publication Type: Technical Report. 11. PROPOSAL OF NEW RESEARCH FORUM

A new Research Forum entitled “Revisiting Correlated Colour Temperature” (Youngshin Kwak, KR) with the Scope described below was approved by Division 1 to establish, with the following ballot results:

Against: 1 Abstention: 3 In favour: 22

Scope: The correlated colour temperature (CCT) has been used as the main descriptor for the colour of white light sources. However, there are issues around CCT. Firstly, CCT is calculated using the obsolete chromaticity coordinates (u, v), and there have been questions why it is the case and whether the current official chromaticity coordinates (u’, v’) provide better correlation with perception. Secondly, CCT does not indicate the visual resemblance between the light sources as originally intended. Research is needed to answer these questions and determine which descriptors can correlate better with perception of the colour of white light, in lighting as well as display applications, since there is not much existing research on this topic. This RF will provide a discussion and information- and data-sharing platform for new descriptors for the colour of white light sources. The ideas for new descriptors (for example CCT calculated in u’v’ space, CCT + Duv, CCT using CIE 2015 colorimetry etc.) will be collected and results of various psychophysical experiments will be exchanged to evaluate the new proposals. As the final output of this RF, new TC proposal will be prepared if the research results show the necessity of new descriptors.

12. PROPOSAL OF NEW LIAISON

Appointment of a new liaison officer, Michael Royer, for liaison from Division 1 to IES (Color Committee), was approved, with the following ballot results: Against: 1 Abstention: 3 In favour: 15

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13. NEXT MEETINGS

• In 2019 the Division 1 Meeting will be held as part of the CIE 29th Session 2019 to be held in Washington DC, USA, 17-22 June 2019.

14. ANY OTHER BUSINESS

None.

15. CLOSE OF MEETING

The Director thanked everyone for attending and declared the meeting closed.

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Appendix – Agenda of the Division Meeting in Taipei

CIE DIVISION 1 VISION AND COLOUR 3rd Meeting of the Kwak Term 28 April 2018 Taipei, Taiwan

AGENDA Division Meeting: 28th April 2018

Opening Session

14:00 – 14:20 1. Opening and welcome by Director, Youngshin Kwak

2. Apologies for absence

3. Membership

4. Attendance

5. Approval of agenda

6. Approval of minutes of Jeju meeting

7. Matters arising from those minutes

8. Report from the Director: Youngshin Kwak

9. Report from the Editor: Peter Hanselaer (absent)

10. Report from the Secretary: Li-Chen Ou

Business Session

14:20 – 14:50 Vision Section: Report – Nana Itoh 14:50 – 15:00 Vision Section: New work items 15:00 – 16:00 Colour Section: Report – Ellen Carter 16:00 – 16:40 Colour Section: New work items 16:40 – 17:00 Any other business: next meetings 17:00 Close of meeting

All times are flexible - there will be a break for coffee/tea during the session.

Li-Chen Ou

Division Secretary