Simulating color appearance change due to interreflections in a spherical concavity under two illuminants

Abstract

Color appearance of an object depends on its spectral reflectance and the illuminant spectral emission. It is also affected by shape and viewing geometry. The color signal reflected from a surface changes considerably if the surface is non-planar due to shadowing and interreflections. If more than one lightsource is illuminating the object, the color appearance should change with the relative positions of the light sources to one another. To verify this, the color appearance of a spherical concavity of high lightness under hvo illuminants with different emissions was simulated. Interreflections within the concavity was modeled using ray optics. It was seen that the object's lightness, chroma and hue changes perceptively with varying concavity depth, as well as with varying source locations.