Abstract
When a shiny surface is viewed binocularly, the specular highlights have different disparities than points on the surface. This study tested whether conflicting highlight disparities contribute to perception of surface shape when other shape cues are available. A recent study by Muryy et al (2013) found that perceived shape followed highlight disparities for mirrored surfaces, but not for surfaces with texture or shading. Is stereo information from highlights overridden by additional surface information, or is there still an influence on quantitative perceived shape? To test this, I varied the depth of specular highlights relative to a surface and measured the effect on perceived extent in depth. Subjects viewed stereo images of elliptical bumps with a flat frontal rim, with varied height and curvature, and estimated height of the bump. Surfaces had smooth shading with and without highlights, and highlights were either accurate or shifted in depth. Simulated illumination was a grid of light fixtures, which was translated and scaled to control the image position of highlights. Surfaces had either high contrast texture or very low contrast texture to vary the quality of surface disparity information. With high contrast texture, highlight disparities did not influence depth estimates. The presence of highlights produced an overall increase in perceived depth, but varying the depth of highlights had no effect. With low contrast texture, depth estimates were strongly influenced by highlight disparities. The presence of highlights improved accuracy, and varying the depth of highlights produced corresponding changes in depth estimates. The effect was the same whether the highlights were consistent or inconsistent with smooth shading. The results demonstrate that binocular highlights can influence perceived shape when other surface information is available but weak. This suggests that highlight disparities are perceptually integrated despite providing conflicting information
Meeting abstract presented at VSS 2017