title: Zen Mountains: An Illusion of Perceptual Transparency.
abstract: The human visual system is usually very successful in segmenting complex natural scenes. During a trip to the Nepalese Himalayas, we observed an impossible example of Nature's beauty: "transparent" mountains. The scene is captured in a photograph in which a pair of mountain peaks viewed in the far distance appear to be transparent. This illusion results from a fortuitous combination of lighting and scene conditions, which induce an erroneous integration of multiple segmentation cues. The illusion unites three classic principles of visual perception: Metelli's constraints for perceptual transparency, the Gestalt principle of good continuation, and depth from contrast and atmospheric scattering. This real-world "failure" of scene segmentation reinforces how ingeniously the human visual system typically integrates complex sources of perceptual information using heuristics based on likelihood as shortcuts to veridical perception.
authors.affiliation: Department of Cognitive Science and ARC Centre for Cognition and its Disorders, Macquarie University, Sydney, Australia.
authors.forename: Susan G
authors.initials: SG
authors.lastname: Wardle
authors.affiliation: Department of Cognitive Science and ARC Centre for Cognition and its Disorders, Macquarie University, Sydney, Australia.
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Carlson
keywords: Gestalt principle of good continuation; depth perception; image segmentation; nonreversing X-junction; perceptual grouping; transparency; visual illusion