Keiji Uchikawa

Human color constancy in cast shadows

The paper investigates human color constancy in cast shadows, finding that color perception remains stable despite changes in lighting conditions and shadow recognition.

Invariant categorical color regions across illuminant change coincide with focal colors

The paper investigates color categories' invariance across illuminant changes and finds that focal colors are more stable than non-focal colors.

Luminosity thresholds of colored surfaces are determined by their upper-limit luminances empirically internalized in the visual system

This study investigates how the visual system determines luminosity thresholds by comparing empirical data with theoretical upper-limit luminances under different illuminants.

Color constancy based on the geometry of color distribution

The paper tests a model for color constancy using psychophysical experiments and finds it outperforms conventional models in estimating illuminant chromaticity.

Explaining #TheShoe based on the optimal color hypothesis: The role of chromaticity vs. luminance distribution in ambiguous image

The paper investigates the #theShoe color perception ambiguity using the optimal color hypothesis, showing that illuminant intensity assumptions affect color appearance and support the hypothesis.