Comment on 'Angle illusion on a picture's surface' by Hammad et al. (2008)

Maniatis, Lydia Maria

doi:10.1163/156856809789822952

Cited by 3 publications

(2 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…When an observer sees a perpendicular angle in a 3D scene on the basis of a non-perpendicular angle in a frontoparallel plane, perception of the angle in the frontoparallel plane is biased toward being perpendicular more than when the angle in the scene is perceived to be non-perpendicular , see also Maniatis, 2009;Kennedy & Hammad, 2010). This effect was observed by using a square that was slanted from the frontoparallel plane in the scene.…”

Section: Perception Of a Perpendicular Anglementioning

confidence: 99%

A role of rectangularity in perceiving a 3D shape of an object

Dvoeglazova,

Sawada

2024

Preprint

View full text Add to dashboard Cite

Rectangularity and perpendicularity of contours are important properties of 3D shape for thevisual system and the visual system can use them as a priori constraints for perceiving shape veridically.The present article provides a comprehensive review of prior studies of the perception of rectangularityand perpendicularity and it discusses their effects on 3D shape perception from both theoretical andempirical approaches. It has been shown that the visual system is biased to perceive a rectangular 3Dshape from a 2D image. We thought that this bias might be attributable to the likelihood of arectangular interpretation but this hypothesis is not supported by the results of our psychophysicalexperiment. Note that the perception of a rectangular shape cannot be explained solely on the basis ofgeometry. A rectangular shape is perceived from an image that is inconsistent with a rectangularinterpretation. To address this issue, we developed a computational model that can recover arectangular shape from an image of a parallelopiped. The model allows the recovered shape to beslightly inconsistent so that the recovered shape satisfies the a priori constraints of maximumcompactness and minimal surface area. This model captures some of the phenomena associatedwith the perception of the rectangular shape that were reported in prior studies. This finding suggeststhat rectangularity works for shape perception by incorporating it with some additional constraints.

show abstract

Section: Perception Of a Perpendicular Anglementioning

confidence: 99%

A role of rectangularity in perceiving a 3D shape of an object

Dvoeglazova,

Sawada

2024

Preprint

View full text Add to dashboard Cite

show abstract

“…We tested the crosstalk prediction about the major axis's size with pictures of a tilted opaque cylinder. Following suggestions made by Maniatis (2009aManiatis ( , 2009b, the cylinder was drawn in parallel perspective, which results in the sides of the cylinder being represented by parallel lines, and simplifies perspective calculations about the ellipse, which is projected similarly in parallel and linear perspective. Further, as Kubovy (1986) and others have noted, for stimuli subtending angles of less than 5°, parallel perspective is used by vision as if it was linear perspective.…”

Section: Introductionmentioning

confidence: 99%

Picture Surface Illusion: Small Effects on a Major Axis

2014

View full text Add to dashboard Cite

Perception of 2-D ellipses on a picture surface is inaccurate-if the ellipses depict circles that are tilted in 3-D, receding from the viewer (Hammad, Kennedy, Juricevic, & Rajani, 2008a, Perception, 37, 504-510). Notably, the minor axis of the ellipse is seen as larger than is true. This illusory effect could be due to the simultaneous presence of optical information for the 2-D ellipse and optical information for the 3-D tilted circle. The optical information for the circle may bias vision's use of the optical information for the ellipse. This theory predicts that illusory effects should occur on the major axis as well as the minor axis; but, we argue, the major axis effect should be smaller than the minor axis effect. We confirm the prediction. Observers looked at target ellipses depicting tops of tilted cylinders. In one experiment observers chose a match for the target from choice sets of seven 2-D ellipses. In the second, observers used the method of adjustment. Both axes were overestimated, the minor axis more than the major, as the theory suggested. We point out that the relative size of the effects matters to the theory, and so the small effect counts for a lot.

show abstract