Biological and Computer Vision

Gabriel Kreiman

Cambridge University Press. 2021. ISBN 9781108649995 

Additional Materials

Chapter III: The phenomenology of seeing

Marr and Poggio defined three fundamental levels of analyses to understand vision: the system's behavior, the computations, and implementation at the neuronal level. The exciting field of psychophysics quantifies behavior through measurements of reaction times, performance, and eye movements. For example, Gestalt laws describe how visual features tend to be grouped to segment objects in an image. Visual recognition is fast: in approximately 200 milliseconds, observers get a glimpse of their surroundings and identify specific objects in a transformation-invariant manner. The recognition process can solve complex problems like inference from partial information due to occlusion, incorporate spatial contextual information, and integrate information over time. Although intuition might suggest that vision is a veridic testament to what is out there in the world, many visual signals are not captured by the brain, and the brain also makes up stuff that does not exist. Visual perception is a construct where brains build an interpretation of the surrounding world based on incoming information and internal rumination. A plethora of visual illusions provide clues about this interpretation process and thus constrain the mechanistic understanding of visual processing.

[1] Figures in powerpoint format for teaching

[2] Further reading

[3] Visual illusions

[4] Gestalt Rules

[5] Holistic Processing

[6] Anorthoscopic Perception

[7] Johansson Experiment

[8] Recognizing Line Drawings

[9] Contextual Effects

[10] Visual Adaptation

[11] The Value of Experience

[12] Visual search

 


Visual Illusions

Michael Bach's compendium of visual illusions

 Best Illustion of the Year Contest


Gestalt Rules

Gestalt rules

Multiple nice examples in Scholarpedia

 


Holistic face processing

Thatcher illusion
ThatcherIllusion

The composite face illusion (image from Psychonomic Bulletin and Review 2017)
CompositeFaceIllusion

The parts-whole illusion
PartsWholeFaces


Anorthoscopic Perception

YouTube Video: Anorthoscope [1:56 duration]

YouTube Video: Zoetrope [1:15 duration]

YouTube Video: Phenakistoscope [3:36 duration]


Inferring motion from light sources experiment (Johansson)

YouTube Video: The Johansson Experiment [3:49 duration]


Recognizing line drawings

A fun computational algorithm trying to recognize line drawings

You Tube Video: Patrick Winston's lecture about interpreting line drawings [49:12 duration]


Contextual Effects

The presidential illusion (Sinha/Poggio)
PresidentialIllusionSinha


Visual Adaptation

YouTube video: The waterfall illusion [1:44 duration]

YouTube video: Another motion aftereffect demo [1:35 duration]


The Value of Experience

The Dalmatian Dog
DalmatianDog

YouTube Video: The hollow mask illusion [1:06 duration]

Stunning 3D street art

3D art from the right and wrong angle
WrongAngle_3DArt

YouTube Video: Making of The Crevasse, 3D art [2:15 duration]


Visual search

What are you searching for? ... And how do you do it? (lecture by Jeremy Wolfe, Aug 16, 2018) [1:06:00 duration]


 
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