The optimal spectral profiles of lighting for naturalness, individual preference, and chromatic diversity were estimated with psychophysical experiments in which observers selected illuminants from a set of metamers of D65 to render outdoor and indoor scenes. For naturalness, the illuminant selected was more spectrally structured than daylight and had a low color rendering index. For preference...

In this paper, we present a method to estimate ambient illuminants using no-flash/flash image pairs. Accurate estimation of the ambient illuminant is useful for imaging applications. In most applications, however, this task is difficult because of the complicated combination of illuminants, surfaces, and camera characteristics during the imaging process. To estimate the scene illumination, a ve...

In constancy experiments, humans report very small changes in appearance with substantial illumination changes. Hermann von Helmholtz introduced the term “discounting the illuminant” to describe 19th century thinking about underlying mechanisms of constancy. It uses an indirect approach. Since observers see objects as constant, observers “must” be able to detect the spatial and spectral changes...

Chromatic Adaptation is the ability of the human visual system to approximately preserve the appearance of an object color, no matter which light “color” illuminates a particular scene. We perceive a white piece of paper as white, regardless whether viewed under a bluish daylight or yellowish tungsten light source. Similar effects can be observed with other color hues. Figure 1 illustrates this...

New descriptors for lightness and chroma are presented that are based on properties of a wraparound Gaussian metameric to the given XYZ tristimulus coordinates. For the 1600 samples of the Munsell glossy set, both descriptors are found to correlate to Munsell value and chroma at least as well as the corresponding CIECAM02 descriptors when the Munsell samples are under the CIE C illuminant. Howe...

Shepard's analysis of how shape, motion, and color are perceptually represented can be generalized. Apparent motion and shape may be associated with a group of spatial transformations, accounting for rigid and plastic motion, and perceived object color may be associated with a group of illuminant transformations, accounting for the discriminability of surface-reflectance changes and illuminant ...