Abstract
BackgroundSurface lightness perception is affected by scene interpretation. There is some experimental evidence that perceived lightness under bi-ocular viewing conditions is different from perceived lightness in actual scenes but there are also reports that viewing conditions have little or no effect on perceived color. We investigated how mixes of depth cues affect perception of lightness in three-dimensional rendered scenes containing strong gradients of illumination in depth.Methodology/Principal FindingsObservers viewed a virtual room (4 m width×5 m height×17.5 m depth) with checkerboard walls and floor. In four conditions, the room was presented with or without binocular disparity (BD) depth cues and with or without motion parallax (MP) depth cues. In all conditions, observers were asked to adjust the luminance of a comparison surface to match the lightness of test surfaces placed at seven different depths (8.5–17.5 m) in the scene. We estimated lightness versus depth profiles in all four depth cue conditions. Even when observers had only pictorial depth cues (no MP, no BD), they partially but significantly discounted the illumination gradient in judging lightness. Adding either MP or BD led to significantly greater discounting and both cues together produced the greatest discounting. The effects of MP and BD were approximately additive. BD had greater influence at near distances than far.Conclusions/SignificanceThese results suggest the surface lightness perception is modulated by three-dimensional perception/interpretation using pictorial, binocular-disparity, and motion-parallax cues additively. We propose a two-stage (2D and 3D) processing model for lightness perception.
Highlights
Much previous research concerning lightness perception makes use of stimuli that are effectively pictures of scenes, but viewed with both eyes
We assume that (1) the comparison patch is perceived as a surface of adjustable albedo aC under a constant but unknown illumination E C and (2) the test patch is perceived as a surface of albedo aT under an illumination E T that varies with depth
In three-dimensional scenes composed of neutral light sources and achromatic surfaces, the luminance of a matte surface depends on both its surface albedo and its location and orientation with respect to the light field across the scene
Summary
Much previous research concerning lightness perception makes use of stimuli that are effectively pictures of scenes, but viewed with both eyes. There is some experimental evidence that perceived lightness under bi-ocular viewing conditions is different from perceived lightness in actual scenes We review the literature concerning lightness perception in three-dimensional scenes and examine what role specific depth cues play in experimental design. We report an experiment contrasting bi-ocular perception of three-dimensional scenes with viewing of identical scenes with binocular disparity and/or motion parallax cues to depth available. There is some experimental evidence that perceived lightness under bi-ocular viewing conditions is different from perceived lightness in actual scenes but there are reports that viewing conditions have little or no effect on perceived color. We investigated how mixes of depth cues affect perception of lightness in three-dimensional rendered scenes containing strong gradients of illumination in depth
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
