Highlight disparity contributes to the authenticity and strength of perceived glossiness

Abstract

The disparity of highlights on specular reflecting surfaces usually differs from the disparity of the surface points. A. Kirschmann (1895) proposed that this fact may be used as a binocular cue for gloss perception. This was confirmed by A. Blake and H. Bülthoff (1990) who found that subjects judged the glossiness of convex ellipsoidal surfaces as most realistic if the disparity of the highlights was close to the physical correct one. Extending on this finding, we investigate more closely whether the effect of highlight disparity depends on the sharpness of the highlight and the relative amount of diffuse and specular reflection. We measured the effect of highlight disparity on both perceived strength and perceived authenticity of gloss. We used complex, three-dimensional curved surfaces that were stereoscopically presented on a CRT. The reflection characteristics were varied using the Phong lighting model. Highlights were presented either with or without highlight disparity. In a rating experiment, subjects were asked to judge the strength and the authenticity of the perceived surface glossiness. The presence of highlight disparity lead to an enhancement of both the authenticity and the strength of perceived glossiness. The latter finding was confirmed in an additional matching experiment.

Highlight microdisparity for improved gloss depiction

“…Doing so, we avoid conflicts, however highlights seem to be painted onto the surface. This is a significant shortcoming, as it is known, that highlight disparity is a strong factor for the perception of gloss [Blake and Bülthoff 1990;Hurlbert et al 1991;Sakano and Ando 2010] and material authenticity [Wendt et al 2008]. Nevertheless on-surface highlights are quite common, presumably for three main reasons: Because artists consider them to be more pleasant to watch; because of performance (e. g., in games that can not afford to shade twice [Sousa et al 2012]); and because the necessary information is missing (e. g., in 2D-to-3D conversion).…”

The perception of gloss: A review

“…Viewing surfaces 931 of reduced bumpiness, but at closer viewing distances, might mean 932 that observers are better able to perceive a finer scale of texture,known about this potential factor, but it is undeniably an imporEven before any detailed study of the perception of gloss began, 938 binocular disparity had already been identified as a potentially 939 invaluable source of information. Kirschmann (1895, as cited inWendt, Faul, & Mausfeld, 2008) proposed that the disparity of 941 highlights on specularly reflecting surfaces usually differs from 942 the disparity produced by points on the surface itself. Czepluch 943(1984( , as cited in Sève, 1993 also emphasised the importance of 944 binocular disparity.…”

Improved gloss depiction using the empirical highlight un-distortion method for 3D image-warping-based stereo rendering

“…Therefore, it is necessary to depict gloss more carefully in stereoscopic rendering when scenes with highly glossy objects are considered. Wendt et al [16] indicated that highlight disparity can improve material authenticity and the strength of gloss by using several visual stimuli tests with the Phong lighting model. In computer graphics, Vangorp et al [17] performed a psychophysical experiment related to material discrimination by rendering synthetic images with a global illumination technique under natural environment lighting.…”