3) Perception III

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is a significant challenge in designing a perceiving machine related to visual input?

Visual input provides consistent information about 3D structures.

All objects in a scene are uniformly illuminated.

2D retinal images can result from multiple 3D configurations. (correct)

Computers can easily differentiate between distinct objects.

How does image complexity affect machine perception?

It complicates the differentiation of distinct objects. (correct)

It reduces the ambiguity of visual input.

It simplifies the process of organizing visual scenes.

It enhances the resolution of detected edges.

What is one approach to understanding perceptual organization mentioned?

Cognitive Mapping

Functionalism

Gestalt Theory (correct)

Structural Analysis

What is a learning objective related to perceiving depth?

Understanding how 3-dimensional space is perceived from 2-dimensional images. Signup and view all the answers

What role do ambiguous visual inputs play in our perception?

They pose difficulties in depth perception for machines. Signup and view all the answers

What type of disparity occurs when objects are closer than the horopter?

Crossed disparity Signup and view all the answers

Which depth cue relies primarily on the visual information provided by a single eye?

Monocular cues Signup and view all the answers

Who were the central figures in the development of the Gestalt school of thought?

Köhler, Koffka, Wertheimer Signup and view all the answers

What is the main argument of the Gestalt school regarding perception?

The whole is greater than the sum of its parts. Signup and view all the answers

What depth cue involves changes in object size perceived with distance?

Relative object height Signup and view all the answers

What is the process of extracting depth information from binocular disparities called?

Stereopsis Signup and view all the answers

What role does prior knowledge play in depth perception?

It aids in top-down processing. Signup and view all the answers

What describes the position of images from the perspective of the right eye for uncrossed disparity?

Further to the left from the right eye’s viewpoint Signup and view all the answers

What is the primary focus of the Gestalt principles of perceptual organization?

Grouping elements to form larger objects Signup and view all the answers

Which principle states that elements that are close together tend to be perceived as belonging together?

Proximity Signup and view all the answers

What does the Law of Prägnanz suggest about perceptual organization?

The simplest and most stable shape will be perceived Signup and view all the answers

Which Gestalt principle allows individuals to perceive a complete figure even when it is incomplete?

Closure Signup and view all the answers

What does the principle of common fate indicate?

Objects that change together are perceived as a single unit Signup and view all the answers

Which principle emphasizes the importance of continuity in perception?

Good continuation Signup and view all the answers

Which principle is suggested to play a role in balancing and symmetry in perception?

Symmetry Signup and view all the answers

What is one criticism of the Gestalt principles mentioned?

There is no clear definition of a 'good' or 'simple' shape Signup and view all the answers

Which aspect of perception does the principle of similarity address?

The basic characteristics of elements Signup and view all the answers

What is a commonality observed in the Gestalt principles?

They all suggest a holistic approach to perception Signup and view all the answers

What function does relative height serve in depth perception?

It indicates how far an object is based on its position relative to the horizon. Signup and view all the answers

Which monocular cue involves objects blocking the view of other objects?

Occlusion Signup and view all the answers

What is the primary difference between monocular cues and binocular cues?

Monocular cues operate with one eye, while binocular cues require both eyes. Signup and view all the answers

What happens to parallel lines as they extend into the distance, according to linear perspective?

They appear to converge. Signup and view all the answers

How does motion parallax contribute to depth perception?

It indicates that distant objects move slower across our field of view than near objects. Signup and view all the answers

What is meant by binocular disparity?

The slight difference in the image location of an object viewed by each eye. Signup and view all the answers

What is foreshortening in the context of depth perception?

It describes the flattening of circles into ovals when tilted away. Signup and view all the answers

What factors contribute to the perception of depth through shadows?

Brightness and orientation with respect to a light source. Signup and view all the answers

What are horopter points in the context of binocular vision?

They are points in space that project to corresponding positions on the retinas. Signup and view all the answers

What is texture gradient and how does it contribute to depth perception?

It involves how objects become smaller and denser in texture with distance. Signup and view all the answers

Study Notes

Cognitive Psychology 1 - Perception III: Depth and Visual Scene Analysis

Course: PSGY1010
Lecturer: Dr Chung Kai Li
Institution: University of Nottingham (UK, China, Malaysia)

Visual Scene Analysis

Visual input provides ambiguous information about 3D world structure.
The same 2D retinal image can correspond to an infinite number of 3D objects.
This ambiguity is exploited by artists in anamorphic street art.
Image complexity makes computer scene analysis difficult.
Computers struggle to organise visual scenes into distinct objects.

How Do We Perceive Depth?

Humans use various image information sources to infer depth.
Monocular Cues (using one eye):
- Relative height
- Relative size
- Occlusion
- Linear perspective
- Texture gradient
- Motion parallax
- Shadows
- Shading
Binocular Cues (using both eyes):
- Disparity

Relative Height and Size

Objects below the horizon with higher bases are perceived as more distant.
If two objects are of equal physical size, the more distant one appears smaller in the visual field.

Occlusion

Closer objects block the view of further objects.

Linear Perspective and Texture Gradient

Parallel lines appear to converge in the distance.
Texture elements become smaller and denser with distance.
Fore-shortening (circles becoming ovals) occurs when a tilted surface recedes away.

Motion Parallax

As we move, more distant objects appear to move past more slowly than closer objects.

Shadows and Shading

Brightness of a surface depends on its orientation relative to the light source.
Cast shadows contribute to depth perception.

Binocular Disparity

Our two eyes receive slightly different images of the world.
This difference in image location (disparity) provides depth information.
The greater the disparity, the closer the object.
Horopter: The set of points in space that project to corresponding points on the two retinas (zero disparity).

How Do We Perceive Objects?

Structuralism:
- Wilhelm Wundt pioneered this approach, popular in the mid-to-late 19th century.
- Proposed that perceptions are the sum of basic sensory elements.
Gestalt Psychology:
- Reaction against structuralism.
- Key figures: Wertheimer, Köhler, and Koffka.
- Argued that the whole is greater than the sum of its parts.
- Emphasized perceptual organisation principles.

Gestalt Principles of Perceptual Organisation

Proximity: Things close together are grouped together.
Similarity: Similar things are grouped together.
Common Fate: Things moving together are grouped together.
Good Continuation: Elements are grouped to form smooth lines, avoiding abrupt changes.
Closure: Incomplete figures are perceived as complete.
Symmetry: Balanced or symmetrical elements are grouped together.

Summary

Key objective: Analyze how we determine depth from 2-D images, and compare and discuss the Structuralist and Gestalt approaches.
Both monocular and binocular cues are significant for perceiving depth.
Perception of depth involves a combination of bottom-up and top-down processes. Depth cues combine to produce our perception.
Both structuralism and Gestalt principles have contributed to our understanding of perceptual organization and object grouping, but are distinct.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Explore the complexities of visual scene analysis and depth perception in this quiz. Learn about monocular and binocular cues that help us interpret our 3D world from 2D images. This content is crucial for understanding human cognition and perception processes.