Partial Exclusion of the Local Effect from the Assessment of Recognized Illuminant Using Depth Separation II: Influence of Depth Separation under Chromatic Illumination

In the previous work we investigated the influence of depth separation on exclusion of the local effect from the assessment of the recognized illuminant. Under whitish illumination, only a portion of the local effect was excluded, while this study, we extended the range of illumination from whitish to chromatic illuminant. We evaluated how the depth separation influences the amount of local effect under the chromatic illumination. Subjects did perceptual achromatic setting under various combinations of local surround and illumination conditions. We found that under chromatic illumination, depth separation is more effective to exclude the local effect even though the local effect was smaller than under whitish chromatic illumination.     

Modeling color preference for different color appearance modes based on perceived color attributes

In our previous study, we found that the color appearance mode affects color preference. Hence, in this study, we propose three color preference models based on the perceived color attributes for different color appearance modes. In the first model, which was used for color preference in the object color mode, the color preference could be predicted from the perceived blackness and the combination of the perceived chromaticness and perceived hue. The second and third models were developed for color preferences in the unnatural object color mode and light source color mode, respectively. In these two models, the color preference could be explained on the basis of the perceived whiteness, perceived chromaticness, and perceived hue.     

Partial Exclusion of the Local Effect from the Assessment of Recognized Illuminant Using Depth Separation

Perceptual achromatic setting has been claimed to be a method of assessing the recognition of illumination in an environment. The result, however, is not spatially valid because of some effect of an immediate area of the test (local effect). We considered a method for excluding this local effect from the assessment. We hypothesized base on the co-planar theory and the recognized visual space of illumination theory that a depth separation between the test and its immediate area would be an effective way. In the first experiment, the perceptual achromatic setting was conducted in a natural scene, with several test luminance levels. The perceptual achromatic locus from two conditions was compared. One condition is the test pasted on a chromatic surround. The other is the test fronto-parallelly separated from the surround. In the second experiment, the perceptual achromatic setting was conducted at the several depth separations. We found that the depth separation decreases the local effect but it was not completely excluded.