Purchase this article with an account.
James Todd, Farley Norman; The perceptual identification of glass. Journal of Vision 2019;19(10):244a. doi: https://doi.org/10.1167/19.10.244a.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
This research was designed to examine a variety of stimulus factors that can influence the perceptual identification of glass. The stimuli included 40 images of solid and hollow glass objects with varying structural complexity and patterns of illumination. They also included another 40 images of objects composed of other non-glass materials to serve as controls. Nine naïve observers rated each stimulus by adjusting four sliders to indicate their confidence that the depicted material was metal, shiny black, glass, or something else, and these adjustments were constrained so that the sum of all four settings was always 100%. The results reveal that confidence ratings for glass categorizations are strongly influenced by the pattern of illumination, and are generally higher for hollow objects than for solid ones. Specular reflections have surprisingly little influence on the identification of glass. When they are presented in isolation, the materials are categorized as shiny black with high confidence. Conversely, when the transmitted light is presented in isolation, the confidence ratings of glass categorizations are comparable to those obtained when reflected and transmitted light are presented in combination. We also included several stimuli that were created by extracting the edges from images of glass and shiny black objects, and we presented them as white lines against a black background. The extracted edges from the glass objects were categorized as glass with much higher confidence than the edges from shiny black objects. This finding suggests that contour structure is an important source of information for the perceptual identification of glass. The informative aspects of that structure include contours that are formed at the interface between hollow and solid regions, and local eddies of light flow that occur in internally concave regions of the surface boundary.
This PDF is available to Subscribers Only