Title:
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Quantifying the colour appearance of displays
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The LUTCHI data are the main colour appearance data used as the basis of many
colour appearance models including CIECAM97s. It was shown in the LUTCHI data
that projected colours are very different from reflective colours however there are
relatively fewer data for projected colours than for reflective colours. In this study, it
is intended to expand the colour appearance data of projected and self-luminous
colours. The additional colours would then help investigate the performance of
existing colour appearance models and, if necessary, enable the derivation of a new
model to improve performance for projected and self-luminous colours.
Before the colour appearance study, firstly the performances of the instruments and
the displays used in the study were investigated. It was found that LCD displays
perform very differently from CRT monitors. Two mathematical characterisation
models for LCD displays were developed named S-Curve Model I and S-Curve
Model II.
The new colour appearance data set, CII-Kwak, was accumulated by a series of
psychophysical experiments. The magnitude estimation technique was applied with
the same experimental set-up as for LUTCHI experiments. The CII-Kwak data set has
20 phases with a total of 28,608 estimations covering various displays, luminance of a
reference white, background luminance factors, surround conditions and stimulus
sizes.
Based on the CII-Kwak and the LUTCHI data set, the colour appearance phenomena
were analysed. It was found that there are systematic colour appearance changes by
the viewing factors investigated. Also eight colour appearance models were tested
using the CII-Kwak and LUTCHI data sets. CIECAM97s-based models performed
similarly well, but all models tested failed to predict several colour appearance
changes, especially under dark surround conditions, which lead to suggest a new
colour appearance model to have a better performance for colour appearance
predictions. The Kwak03 model was derived from the CIECAM02 with several major
modifications such as the cone signal ratios and the omission of the dynamic function.
The Kwak03 model was shown to outperform all the other colour appearance models
tested and also to be capable of predicting all colour appearance phenomena found in
this study with good accuracy.
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