visual perception principles Flashcards
what are visual perception principles?
Rules applied to visual information to assist our organisation and interpretation of it
How would you describe Gestalt principles?
how we organise the features of a visual scene by grouping them to perceive a complete form
What is figure-ground organisation?
dividing a visual scene into a ‘figure’ which stands out from the surroundings, the ‘ground’
An example of figure-ground organisation
In a stop sign, the white ‘STOP’ is the figure, and the red surroundings are the ground.
What is closure?
mentally closing, or ignoring gaps in a visual image to perceive incomplete objects as complete
An example of closure
The IBM logo features the letter ‘IBM’ separated with several gaps. We use closure to perceive the letters as complete
What is similarity?
Parts of a visual image with similar features (such as size or shape) are grouped together as they appear to belong as a unit.
An example of similarity
We perceive people wearing the same school uniform as attending the same school
What is proximity?
Parts of a visual image which are positioned close together are perceived to belong in a group
An example of proximity
A series of letters located physically close together may be grouped and perceived as a word
What is depth perception?
the ability to accurately estimate the distance of objects and hence perceive the world in 3D
What are depth cues?
Sources of information from the environment or from within our body that help us to perceive depth
Binocular depth cues require?
The use of both eyes
What is convergence?
The closer an object, the greater tension in the eye muscles, as your eyes turn inward to focus on closer objects. This allows the brain to interpret length
What is retinal disparity?
The slight difference in the location of the visual images on the retina. The two different retinal images combine in the brain, and any difference between the two images provide depth information.
Are binocular depth cues best for long or short distances?
Short. Therefore, if our vision becomes limited to one eye, it is relatively difficult to focus on detail over short distances.
What do monocular depth cues require?
The use of only one eye
What is accommodation?
Automatic adjustment of the shape of the lens to focus an object depending on how far it is.
How does the lens change in accommodation?
The lens bulges when an object is close, to focus the light rays reflected from the object.
The lens flattens when the objects are further away.
The lens is controlled by the ciliary muscles.
What are pictorial cues?
Monocular depth cues used by artists to create depth and distance on 2D surfaces (paper)
What is linear perspective?
The apparent convergence of parallel lines as they recede into the distance
What is interposition?
When one object partially blocks another, the object in front is perceived as closer
What is texture gradient?
The gradual reduction of detail in a surface as it recedes into the distance
What is relative size?
The tendency to visually perceive the object that produces the largest image on the retina as being closer.
