Material and shape perception based on two types of intensity gradient information

Masataka Sawayama, Shin'ya Nishida

Abstract: Author summary Objects in our visual world contain a variety of material information. Although such information enables us to experience rich material impressions, it can be a distraction for the estimation of other physical properties such as shapes, albedos, and illuminations. The coupled estimation of these properties we humans perform in daily situations is one of the fundamental mysteries in visual neuroscience. Here, we show that material and shape perception depend on two different types of intensity gradient information. Specifically, our image analyses and psychophysical experiments show that a human’s material perception relies mainly on the intensity gradient magnitude information, while shape perception relies mainly on the intensity gradient order information. In addition, we show that the intensity order information can be utilized for discriminating albedo changes on an object surface from other physical properties including specular highlights.