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We investigated processes that determine the depth localization of monocular points which have no unambiguous depth. It is known that horizontally adjacent binocular objects are used in depth localization and for a distance of 25-40 min arc monocular points localize to the leading edge of a depth constraint zone, which is an area defined by the visibility lines between which the points in the r...

BACKGROUND /aims: Paediatric squint surgery appears to be declining. This study aims to identify if this is so and, if so, why. METHODS Retrospective review of (1) episodes of paediatric squint surgery in Scotland and Tayside, 1986-2001, (2) presentations to orthoptists (Tayside) during 1986 and 1996. RESULTS (1) Overall, a 58% fall in surgery in Scotland and 59% in Tayside. For esotropia, ...

Does human vision show the contrast invariance expected of an ideal stereoscopic system for computing depth from disparity? We used random-dot stereograms to investigate the luminance contrast effect on perceived depth from disparity. The perceived depth of disparity corrugations was measured by adjusting the length of a horizontal line to match the perceived depth of the corrugations at variou...

I develop a model of R&D cooperation with uncertain research outcomes. In this model asymmetric outcomes of R&D competition emerge naturally. Therefore ex-ante and ex-post R&D cooperation can be studied as alternatives for firms. Using this model I compare welfare losses under ex-ante and ex-post R&D cooperation as the degree of product market competition varies. It emerges that the relative si...

The visual system uses a variety of cues for form perception, including motion, color, binocular disparity, texture, and luminance. Physiological evidence suggests that these cues are processed by different neural mechanisms. Do the cues processed by some mechanisms convey any advantage for form perception when compared to cues processed by another? In response to this question we assessed the ...

Autostereograms can be perceived in different well-defined spatial levels. Therefore they are an excellent tool with which to examine spatiotemporal processes of multistable three-dimensional perception. We study properties of spatial ambiguity such as phase transitions between different spatial levels and hysteresis in perception with and without noise. We show that the perception of physical ...

This paper performs the first investigation into depth for large-scale human action recognition in video where the depth cues are estimated from the videos themselves. We develop a new framework called depth2action and experiment thoroughly into how best to incorporate the depth information. We introduce spatio-temporal depth normalization (STDN) to enforce temporal consistency in our estimated...

In the laboratory, thresholds for stereoscopic depth perception are usually determined by asking observers to discriminate between a stimulus with a given depth offset and its mirror image. Threshold is most often defined as the disparity difference that yields 75% or 83% correct responses. Disparities used for clinical tests of stereopsis are much higher. Here it is argued that, among other fa...