CIE TC804 Progress Report

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CIE TC8-04 Progress Report

• Naoya KATOH, TC Chair
• Sony Corporation

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Terms of Reference

• "To investigate the state of adaptation of the
  visual system when comparing soft-copy images on
  self-luminous displays and hard copy images
  viewed under various ambient lighting
  conditions."

Established in 1998
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Past TC Meetings and TC Members

• Meetings
• 1st Meeting (Jul.25/99) Warsaw
• 2nd Meeting (Nov.16/99) Scottsdale
• 3rd Meeting (Nov.9/01) Scottsdale
• 4th Meeting (Nov.12/02) Scottsdale
• 5th Meeting (Nov.04/'03) Scottsdale
• Members
• 7 countries, 17 members
• France (2)- A. Gatt, E. Khoury
• UK (2)- R. Luo, M. Pointer,
• Hungary (4)- P. Bodrogi, I. Kucsera, J. Schanda,
  K. Wenzel
• Japan (2)- N. Katoh TC Chair, N. Ohta
• Sweden (1)- M. Billger
• Thailand (1)- S. Sueeprasan
• USA (5)- P. Alessi, M. Fairchild, D. McDowell,
  T. Newman, E. Pirrotta

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TC Works

• Survey past relevant works (99)http//www.colou
  r.org/tc8-04/Past_survey.html
• Set a standard experimental method (99)
  http//www.colour.org/tc8-04/Experiment_guideline.
  html
• Perform cross-examinations at different
  laboratories and compare the experimental results
  (00-01)
• Sony Corp (JP) N. Katoh, K. Nakabayashi,
  "Applying Mixed Adaptation to Various Chromatic
  Adaptation Transformation (CAT) Models," PICS
  Conf., (2001)
• Univ. Derby (UK) S. Sueeprasan, R. Luo,
  "Incomplete Chromatic Adaptation under Mixed
  Illuminations ," Color Imaging Conf. 9, (2001)
• Both experimental results indicated that mixed
  adaptation is 40-60.
• Coordinate with other CIE works (02-03)
• CIE1592004 A Colour Appearance Model for Colour
  Management Systems CIECAM02
• Used same CAT matrix and Incomplete Adaptation
  Method (D-factor).

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Since the last meeting

• Nov.04/'03 TC8-04 meeting (Tuesday, 700-830pm)
• Dec.15/'03 DRAFT 8 distributed to TC
• Jan.06/'04 DRAFT 9 distributed to TC
• Jan.14/'04 DRAFT 10 for TC balloting
• Feb.14/'04 TC ballot closed - 6 approval/0
  disapproval
• Feb.25/'04      DRAFT 11 sent to CIE/CB
• Mar.22/'04      DRAFT 12 sent to CIE/CB
• Apr.30/'04      NB ballot started.
• Jun.30/'04      NB ballot closed - Div Member
  11 in favor/0 abstention/0 Rejected - BA
  Member 5 in favor/2 abstention/0 Rejected
• Oct.30/'04 Final corrections sent to CIE/CB
• Nov.09/'04 Technical Report Published!

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Recommended Calculation for Mixed Chromatic
Adaptation

• Transformation to cone signals (LMS)
• Used MCAT02 defined in CIECAM02
• Calculation for adapted white point
• Incomplete chromatic adaptation (ICA)
• Mixed chromatic adaptation (MCA)
• Chromatic adaptation transform (CAT)
• Simple von Kries adaptation model

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Calculation for adapted white point

• Incomplete chromatic adaptation (ICA)
• Used D-factor defined in CIECAM02
• Mixed chromatic adaptation (MCA)

Ambient Illumination
Adapted White Point
Softcopy White Point
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Mixed Chromatic Adaptation Ratio

• Mixed chromatic adaptation ratio is around 60
  (40 60).

Result of image-matchingexperiments (Katoh 1998)
Time course of chromatic adaptation (Fairchild
1993)
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Worked Example