Contributions of monocular and binocular cues to distance discrimination in natural scenes

Abstract

Little is known about distance discrimination in real scenes, especially at long distances. This is not surprising given the logistical difficulties of making such measurements. To circumvent these difficulties, we collected 81 stereo images of outdoor scenes, together with precisely registered range images that provided the ground-truth distance at each pixel location. We then presented the stereo images in the correct viewing geometry and measured the ability of human subjects to discriminate the distance between locations in the scene, as a function of absolute distance (3 m to 30 m) and the angular spacing between the locations being compared (2°, 5°, and 10°). Measurements were made for binocular and monocular viewing. Thresholds for binocular viewing were quite small at all distances (Weber fractions less than 1% at 2° spacing and less than 4% at 10° spacing). Thresholds for monocular viewing were higher than those for binocular viewing out to distances of 15–20 m, beyond which they were the same. Using standard cue-combination analysis, we also estimated what the thresholds would be based on binocular-stereo cues alone. With two exceptions, we show that the entire pattern of results is consistent with what one would expect from classical studies of binocular disparity thresholds and separation/size discrimination thresholds measured with simple laboratory stimuli. The first exception is some deviation from the expected pattern at close distances (especially for monocular viewing). The second exception is that thresholds in natural scenes are lower, presumably because of the rich figural cues contained in natural images.

Factors affecting depth perception and comparison of depth perception measured by the three-rods test in monocular and binocular vision

“…[ 21 ] compared monocular and binocular performance on depth-interval estimation and discrimination tasks, at distances of 4.5, 9.0, and 18.0 m and found that binocular vision can significantly improve the accuracy and precision of depth estimation up to 18.0 m. McCann et al. [ 22 ] reported that thresholds for binocular viewing were small at all distances and those for monocular viewing were higher than those for binocular viewing at distances of between 15.0 and 20.0 m, beyond which they were similar, while Palmisano et al. [ 23 ] reported larger binocular estimates of depth with a lit foreground than in darkness, and further increases as the observation distance increased from 20.0 to 40.0 m. Those studies were conducted for static objects.…”

“…McKee and Taylor [16] measured binocular and monocular depth thresholds for separating a pair of metal rods presented at 1.22 m and concluded that binocular thresholds were markedly superior to the monocular thresholds in the isolated setting of the target objects. Allison et al [21] compared monocular and binocular performance on depth-interval estimation and discrimination tasks, at distances of 4.5, 9.0, and 18.0 m and found that binocular vision can significantly improve the accuracy and precision of depth estimation up to 18.0 m. McCann et al [22] reported that thresholds for binocular viewing were small at all distances and those for monocular viewing were higher than those for binocular viewing at distances of between 15.0 and 20.0 m, beyond which they were similar, while Palmisano et al [23] reported larger binocular estimates of depth with a lit foreground than in darkness, and further increases as the observation distance increased from 20.0 to 40.0 m. Those studies were conducted for static objects. The three-rods test used in this study has been reported to examine a kind of dynamic stereopsis in response to a moving rod and also to analyse the speed of response by eye-hand coordination to push a button to stop the moving rod.…”

Binocular vision supports the development of scene segmentation capabilities: Evidence from a deep learning model

“…Heesy, 2009). Although benefits of binocular viewing have been demonstrated in laboratory situations for a number of tasks, including color constancy (Yang & Shevell, 2002), object tracking and visual search (Dunser & Mancero, 2009;Nakayama & Silverman, 1986;Vishwanathan & Mingolla, 2002), and the perception of shape, depth, distance and heading direction (Brenner & van Damme, 1999;McCann, Hayhoe, & Geisler, 2018;Macuga, Loomis, Beall, & Kelly, 2006;Scarfe & Hibbard, 2006;van den Berg & Brenner, 1994), a number of factors suggest that its benefits may be more limited in natural environments. One commonly raised issue is that deficits in binocular vision are relatively commonplace.…”

Cerebellar projections to the macaque midbrain tegmentum: Possible near response connections

“…Estimating target distance requires a complex analysis of a variety of cues, including visual disparity, vergence angle, blur, ocular accommodation, target size, and perspective (Leigh & Zee, 2015;McCann et al, 2018). The capabilities of the cerebellum would seem well suited to ensuring precision in such a task.…”