2018-02-05 Depth Perception

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# 2018-02-05 Depth Perception
## PSY 525.001 • Vision Science • 2018 Spring
### Rick Gilmore
### 2018-02-05 14:23:53

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# Today's topics

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## Discuss project proposal

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## Depth perception

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## Discuss Leopold & Logothetis, N. K. (1996).

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## Term project

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<http://psu-psychology.github.io/psy-525-vision-spring-2018/project-proposal.html>

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# Perceiving surfaces orientation (spatial layout)

## Slant, tilt, distance

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## Marr's 2.5 D sketch

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# Depth perception

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>*"For those of a creationist bent, one could note that God must have loved depth cues, for He made so many of them"*

Yonas & Granrud, 1985, p. 45

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## Kinetic

## Binocular

## Static (pictoral)

## Sensorimotor

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## Monocular (kinetic, static, some sensorimotor) vs. binocular cues

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## Kinetic cues to depth

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## [Kinetic depth effect (KDE)](https://en.wikipedia.org/wiki/Kinetic_depth_effect)

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<p><a href="https://commons.wikimedia.org/wiki/File:Spinning_Dancer.gif#/media/File:Spinning_Dancer.gif"><img src="https://upload.wikimedia.org/wikipedia/commons/2/21/Spinning_Dancer.gif" alt="Spinning Dancer.gif"></a><br>By <a rel="nofollow" class="external text" href="http://procreo.jp/about.html">Nobuyuki Kayahara</a> - <a rel="nofollow" class="external text" href="http://procreo.jp/labo/labo13.html">Procreo Flash Design Laboratory</a>, <a href="https://creativecommons.org/licenses/by-sa/3.0" title="Creative Commons Attribution-Share Alike 3.0">CC BY-SA 3.0</a>, <a href="https://commons.wikimedia.org/w/index.php?curid=3526328">Link</a></p>

This one is also bistable

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## Kinetic depth effect

3D structure perceived from temporal sequence of 2D (outline-only) views.

Reported in Wallach, H., & O’Connell, D. N. (1953). The Kinetic Depth Effect. *Journal of Experimental Psychology*, *45*(4), 205.

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## Structure from motion

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## Motion parallax

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## The geometry of motion parallax

Where is fixation? What is the direction of motion?

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## Texture accretion & deletion

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## Texture accretion & deletion

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# Optic flow

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## Optic flow and autonomous flight

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## Binocular cues to depth

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## Stereopsis

Perception of depth and 3D structure from stimulation of both eyes

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## Horopter

a line or surface containing all those points in space whose images fall on corresponding points of the retinas of the two eyes.

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## Retinal disparity

Retinal image positions are "disparate" or different

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## [Random-dot stereograms](https://en.wikipedia.org/wiki/Random_dot_stereogram)

Invented by [Béla Julesz](https://en.wikipedia.org/wiki/B%C3%A9la_Julesz)

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```r
library(imager)
n_pts <- 100
left_img <- array(round(runif(n=n_pts^2),0), dim = c(n_pts, n_pts))
plot(as.cimg(left_img), axes=FALSE)
```

![](2018-02-05-depth-perception_files/figure-html/rds-1.png)

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```r
right_img <- left_img
square_pix <- 20
center_square <- right_img[floor(n_pts/2-square_pix/2):floor(n_pts/2+square_pix/2),floor(n_pts/2-square_pix/2):floor(n_pts/2+square_pix/2)]
plot(as.cimg(center_square), axes=FALSE)
```

![](2018-02-05-depth-perception_files/figure-html/rds_2-1.png)

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## Auto-stereogram

Can't really fuse these from *projected* image. Why?

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## The "correspondence" problem

How do retinal image points/edges correspond to object points/edges?

Why can it take time to "fuse" stereograms?

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## Marr-Poggio algorithm for solving

Use: surface opacity & surface continuity heuristics

Iterate until a best-fitting solution is found

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## Da Vinci stereopsis

Different eyes see different portions of surfaces

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## Geometry of self-motion, object-motion, and disparity

Durgin, F. H., Proffitt, D. R., Olson, T. J., & Reinke, K. S. (1995). Comparing depth from motion with depth from binocular disparity. Journal of experimental psychology. Human perception and performance, 21(3), 679–699. psycnet.apa.org. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/7790841

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## Static (pictoral) cues to depth

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## Linear Perspective

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<p><a href="https://commons.wikimedia.org/wiki/File:Ponzo_illusion.gif#/media/File:Ponzo_illusion.gif"><img src="https://upload.wikimedia.org/wikipedia/commons/0/02/Ponzo_illusion.gif" alt="Ponzo illusion.gif"></a><br>Public Domain, <a href="https://commons.wikimedia.org/w/index.php?curid=1211098">Link</a></p>

## Linear perspective + elevation over horizon = [Ponzo illusion](https://en.wikipedia.org/wiki/Ponzo_illusion)

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## Relative size

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## [Ames room](https://en.wikipedia.org/wiki/Ames_room)

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<https://en.wikipedia.org/wiki/Ames_room>

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## [Aerial perspective](https://en.wikipedia.org/wiki/Aerial_perspective)
## Defocus blur

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<p><a href="https://commons.wikimedia.org/wiki/File:SerraEstrela-MAR2007-5.jpg#/media/File:SerraEstrela-MAR2007-5.jpg"><img src="https://upload.wikimedia.org/wikipedia/commons/thumb/1/10/SerraEstrela-MAR2007-5.jpg/1200px-SerraEstrela-MAR2007-5.jpg" alt="SerraEstrela-MAR2007-5.jpg" height=450px></a><br>By <a href="//commons.wikimedia.org/wiki/User:Alvesgaspar" title="User:Alvesgaspar">Joaquim Alves Gaspar</a> - <span class="int-own-work" lang="en">Own work</span>, <a href="https://creativecommons.org/licenses/by-sa/2.5" title="Creative Commons Attribution-Share Alike 2.5">CC BY-SA 2.5</a>, <a href="https://commons.wikimedia.org/w/index.php?curid=1869570">Link</a></p>

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## Interposition, occultation

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## Texture gradients

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<p><a href="https://commons.wikimedia.org/wiki/File:Gustave_Caillebotte_-_Paris_Street;_Rainy_Day_-_Google_Art_Project.jpg#/media/File:Gustave_Caillebotte_-_Paris_Street;_Rainy_Day_-_Google_Art_Project.jpg"><img src="https://upload.wikimedia.org/wikipedia/commons/thumb/1/17/Gustave_Caillebotte_-_Paris_Street%3B_Rainy_Day_-_Google_Art_Project.jpg/1200px-Gustave_Caillebotte_-_Paris_Street%3B_Rainy_Day_-_Google_Art_Project.jpg" alt="Gustave Caillebotte - Paris Street; Rainy Day - Google Art Project.jpg"></a><br>By <a href="https://en.wikipedia.org/wiki/en:Gustave_Caillebotte" class="extiw" title="w:en:Gustave Caillebotte">Gustave Caillebotte</a> - <a rel="nofollow" class="external text" href="//www.google.com/culturalinstitute/asset-viewer/5wEUCOlEf-EaVQ">5wEUCOlEf-EaVQ at Google Cultural Institute</a> maximum zoom level, Public Domain, <a href="https://commons.wikimedia.org/w/index.php?curid=21909139">Link</a></p>

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<http://psychsciencenotes.blogspot.com/2011/08/mirrors-are-literally-windows-to.html>

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## Lighting, shading, & shadow cues

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# Sensorimotor cues to depth

## Palmer's "ocular" cues

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## Vergence

Eyes (typically) *converge* on a 3D point. Angle of vergence related to 3D geometry.

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## Accommodation

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<<iframe width="560" height="315" src="https://www.youtube.com/embed/IsoHFoY5q7o?rel=0" frameborder="0" allow="autoplay; encrypted-media" allowfullscreen></iframe>

## Vergence, pupil diameter change, + accommodation

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## Vestibular system detects head rotation, translation

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## Vestibular signals speed, direction of rotation, translation

## More motion parallax with head translation than rotation

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## Comparing the cues

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## Integrating the cues

Welchman, A. E. (2016). The human brain in depth: how we see in 3D. *Annual Review of Vision Science*. annualreviews.org. Retrieved from http://www.annualreviews.org/doi/abs/10.1146/annurev-vision-111815-114605

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# Heuristics

## About world, illumination conditions

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>*"Only in the vision scientist's laboratory or under other conditions designed specifically to deceive the visual system do we regularly fail to apprehend the actual distance to environmental surfaces."*

Palmer, 1999, p. 202

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<p><a href="https://commons.wikimedia.org/wiki/File:Vertical%E2%80%93horizontal_illusion.png#/media/File:Vertical%E2%80%93horizontal_illusion.png"><img src="https://upload.wikimedia.org/wikipedia/commons/3/30/Vertical%E2%80%93horizontal_illusion.png" alt="Vertical–horizontal illusion.png"></a><br>By <a href="//commons.wikimedia.org/w/index.php?title=User:S-kay&amp;action=edit&amp;redlink=1" class="new" title="User:S-kay (page does not exist)">S-kay</a> - <span class="int-own-work" lang="en">Own work</span>, Public Domain, <a href="https://commons.wikimedia.org/w/index.php?curid=8845534">Link</a></p>

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## Vertical lines seem longer than horizontal ones

Vertical-horizontal illusion

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## Reflects statistics of visual experience?

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Howe, C. Q., & Purves, D. (2002). Range image statistics can explain the anomalous perception of length. Proceedings of the National Academy of Sciences of the United States of America, 99(20), 13184–13188. Retrieved from http://dx.doi.org/10.1073/pnas.162474299

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Geisler, W. S. (2008). Visual Perception and the Statistical Properties of Natural Scenes. *Annual Review of Psychology*, *59*(1), 167–192. Retrieved April 17, 2012, from http://www.annualreviews.org/doi/abs/10.1146/annurev.psych.58.110405.085632

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Potetz, B., & Lee, T. S. (2003). Statistical correlations between two-dimensional images and three-dimensional structures in natural scenes. *Journal of the Optical Society of America. A, Optics, image science, and vision*, *20*(7), 1292–1303. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/12868635

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# Break time

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# Leopold & Logothetis, N. K. (1996)

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# Core phenomena

- Binocular rivalry
- Neural basis of binocular rivalry
- Neural basis of "conscious" visual experience

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# Next time...

## Perceptual organization

## Size, shape, orientation, & position

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Slides created via the R package [**xaringan**](https://github.com/yihui/xaringan). Rendered HTML and supporting files are pushed to GitHub where GitHub's 'pages' feature is used to host and serve the course website.