Blur and Contrast as Pictorial Depth Cues

O’Shea, Robert P; Govan, Donovan G.; Sekuler, Robert

doi:10.1068/p260599

Cited by 47 publications

(20 citation statements)

References 23 publications

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“…Some of these cues result from binocularity such as ocular vergence angle (Collewijn & Erkelens, 1990;Mon-Williams, Tresilian, & Roberts, 2000;Richard & Miller, 1969;Ritter, 1977;Viguier, Clement, & Trotter, 2001) and retinal disparity (Bishop, 1989;Mayhew & Longuet-Higgins, 1982), whilst monocular cues such as retinal blurring (Mather, 1997;O'Shea, Govan, & Sekuler, 1997), ocular accommodation (MonWilliams & Tresilian, 1999, 2000, as well as the surface texture, contrast and shading of fixated objects are also influential (Gonzalez & Perez, 1998;Johnston, 1991;Johnston, Cumming, & Parker, 1993;O'Shea, Blackburn, & Ono, 1994). …”

Section: General Introductionmentioning

confidence: 99%

Looming motion primes the visuomotor system.

Skarratt¹,

Gellatly²,

Cole³

et al. 2014

Journal of Experimental Psychology: Human Perception and Perfor

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A wealth of evidence now shows that human and animal observers display greater sensitivity to objects that move toward them than to objects that remain static or move away. Increased sensitivity in humans is often evidenced by reaction times that increase in rank order from looming, to receding, to static targets. However, it is not clear whether the processing advantage enjoyed by looming motion is mediated by the attention system or the motor system. The present study investigated this by first examining whether sensitivity is to looming motion per se or to certain monocular or binocular cues that constitute stereoscopic motion in depth. None of the cues accounted for the looming advantage. A perceptual measure was then used to examine performance with minimal involvement of the motor system. Results showed that looming and receding motion were equivalent in attracting attention, suggesting that the looming advantage is indeed mediated by the motor system. These findings suggest that although motion itself is sufficient for attentional capture, motion direction can prime motor responses.

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Section: General Introductionmentioning

confidence: 99%

Looming motion primes the visuomotor system.

Skarratt¹,

Gellatly²,

Cole³

et al. 2014

Journal of Experimental Psychology: Human Perception and Perfor

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show abstract

“…Pentland (1987) identified image blur as a more general source of depth information both in machine vision and in human vision. However, only recently has blur-mediated depth perception become a matter for investigation in psychophysical studies (Marshall et al 1996;Mather 1996Mather , 1997O'Shea et al 1997;Mather and Smith 2000). Owing to the depth-of-focus limitations of the eye's optics, retinal images of objects nearer or farther than the plane of fixation are blurred by an amount that depends on their relative distance from the fixation plane.…”

Section: Introductionmentioning

confidence: 99%

Blur Discrimination and its Relation to Blur-Mediated Depth Perception

Mather

Smith

2002

Perception

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Abstract. Retinal images of three-dimensional scenes often contain regions that are spatially blurred by different amounts, owing to depth variation in the scene and depth-of-focus limitations in the eye. Variations in blur between regions in the retinal image therefore offer a cue to their relative physical depths. In the first experiment we investigated apparent depth ordering in images containing two regions of random texture separated by a vertical sinusoidal border. The texture was sharp on one side of the border, and blurred on the other side. In some presentations the border itself was also blurred. Results showed that blur variation alone is sufficient to determine the apparent depth ordering. A subsequent series of experiments measured blur-discrimination thresholds with stimuli similar to those used in the depth-ordering experiment. Weber fractions for blur discrimination ranged from 0.28 to 0.56. It is concluded that the utility of blur variation as a depth cue is constrained by the relatively mediocre ability of observers to discriminate different levels of blur. Blur is best viewed as a relatively coarse, qualitative depth cue.

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“…By considering the gamma function of the monitor (calibration curve), these two parameters are determinant features for tasks related to the perception of intensity profiles [23]. We have not considered other contrast definitions such as root mean square (RMS), since they depend on the relation between contrast and blur [24]. In consequence, they are not suitable definitions for our experiment, since we are looking for separated dependencies on these two parameters.…”

Section: Definitionsmentioning

confidence: 98%