This study investigates the colour appearance for unrelated colours with two sizes (0.5° and 10°) under photopic and mesopic vision. The same test colours with different field sizes were assessed under four different luminance levels with reference white ranging from 60 to 0.1cd/m2. Eight phases of psychophysical experiments were conducted to obtain visual data assessed by a panel of 9 observers. The results showed that brightness and colourfulness increased with luminance level. For photopic vision, brightness and colourfulness were relatively increased for large stimuli size. For the mesopic level (0.1 cd/m2), the results were about 50% brighter and 60% more colourful for 10° stimuli than for 0.5° stimuli. The results were used to test two colour appearance models: CAM97u and CIECAM02. The latter model was revised for predicting unrelated colours. It was found that CAM97u predicted brightness visual results more accurately than CIECAM02 and opposite was found for predicting colourfulness visual results. For predicting hue visual results, CAM97u and CIECAM02 gave satisfactory predictions.
Chenyang Fu, Changjun Li, M. Ronnier Luo, R. W. G. Hunt, Michael R. Pointer, "Quantifying Colour Appearance for Unrelated Colour under Photopic and Mesopic Vision" in Proc. IS&T 15th Color and Imaging Conf., 2007, pp 319 - 324, https://doi.org/10.2352/CIC.2007.15.1.art00060