Illustration of the Capability and Limits of Visual Perception - - PowerPoint PPT Presentation

▶

Sep 11, 2022 211 likes •432 views

Illustration of the Capability and Limits of Visual Perception Aude Oliva Brain and Cognitive Sciences MIT Email: oliva@mit.edu Web site: cvcl.mit.edu Demo 1 What do you see at a glance? Fast visual perception & Temporal constraints

SLIDE 1

Illustration of the Capability and Limits

f Visual Perception

Aude Oliva Brain and Cognitive Sciences MIT Email: oliva@mit.edu Web site: cvcl.mit.edu

SLIDE 2

Demo 1 What do you see at a glance? Fast visual perception & Temporal constraints

n visual processing

SLIDE 3

Incorrect: SOA n+1 = SOAn + 10msec Correct: SOA n+1 = SOAn – 30msec Compare psychophysic al thresholds for a variety of tasks

Varying image duration

80 msec mask duration

Temporal image understanding: Measuring perceptual thresholds of various tasks Temporal image understanding: Measuring perceptual thresholds of various tasks

Greene & Oliva (2005)

SLIDE 4

Temporal image understanding: Measuring perceptual thresholds of various tasks

Threshold (in msec) for 75 % correct

Global Scene Properties

bject in cluttered scene

135 msec ~ 21 msec ~ 24 msec

Greene & Oliva (2005, in preparation)

SLIDE 5

Demo 2 What do see when you are looking around? Visual search & Attention

SLIDE 6

SLIDE 7

How much did you miss…

SLIDE 8

Look for a person in the next scene

SLIDE 9

SLIDE 10

SLIDE 11

Where will the eye be drawn?

Distractor INSIDE Context region Distractor OUTSIDE Context region % trials on which eyes drawn to the distractor chance

Saliency * Context

First fixation drawn to the Salient object WITHIN the Contextual region

Kenner, Hidalgo-Sotelo, Oliva (2005)

SLIDE 12

Contextual Guidance Model

Torralba, Oliva et al (2006)

SLIDE 13

Demo 3 Principles of visual perception and perceptual grouping

SLIDE 14

Hybrid Images Hybrid Images

Angry man Neutral woman

Web site: http://cvcl.mit.edu/hybridimage.htm

SLIDE 15

What you see…

Hybrid Images

It’s a woman! I see an angry guy From Far Away Up Close

SLIDE 16

Schyns & Oliva (1997)

SLIDE 17

Hybrid Images Hybrid Images

Oliva, Torralba, Schyns (2006)

SLIDE 18

SLIDE 19

Reorganization of the shadows as a motorcycle

Perceptual Grouping Perceptual Grouping

Oliva, Torralba, Schyns (2006)

SLIDE 20

Changing expression Changing expression

Sad Surprised

Oliva, Torralba, Schyns (2006)

SLIDE 21

Perceptual & Cognitive Hysteresis

Group 1: Walk towards the face Group 2: Walk away from the face

Brady & Oliva (in preparation)