A STUDY OF COLOR APPEARANCE MODELS' PERFORMANCE USING SINGLE COLOR STIMULI IN A SIMPLE VIEWING FIELD UNDER AN AVERAGE SURROUNDING

摘要

The goal of this study is the evaluation of various color models for achieving accurate color rendition between a self-luminous reproduced color (softcopy) and a original surface color (hardcopy) in a bright room under an average surrounding. The color models tested were CIELAB, von Kries, ZLAB, LLAB, Hunt and CIECAM97 models. The whole experiment was divided into 4 phases. A set of 36 reflection single stimuli was chosen to be the original colors. A forced-choice paired-comparison experiment was performed. Observers accessed the color-fidelity quality of each reproduced color, processed using a particular model of interest, in a simple field using a 7-point category scale. The laws of both comparative judgement and category judgement were applied to analyze the visual data. Analysis shows that the CIELAB (also CIEXYZ) system is adequate to implement color matches across media for the symmetrical viewing conditions. For asymmetric viewing conditions wherein different chromaticities were used for hardcopy and softcopy reference whites, the CIECAM97's model overall performed better than other models. Moreover, the results obtained using the category ranking method indicate that those good performing models also gave satisfactory color-fidelity quality. Successively, a set of experiments will be carried out to achieve the ultimate goal of establishing a reliable color model, capable of predicting the change of perceived appearance of colors under a wide range of media/viewing conditions.