Visual Perception - Principles Flashcards
What are the four Gestalt principles?
Figure ground, closure, proximity and similarity
Define: gestalt principles
Processes in which we organise parts of a scene by grouping them to perceive a whole, complete picture
What is figure ground and provide an example of it?
Organising an image into a figure (foreground) which stands out from the ground (background)
Eg. Stop sign, the white writing is the figure and the red is the ground
How do we separate figure and ground and what does this thing belong to the figure or the ground?
Contour - separation between figure and ground
Belongs to the figure
What can form when the contour can’t be easily defined/belongs to both figure and ground?
Camouflage, ambiguous/ reversible figured
Define: closure,
Provide an example
Tendency to close up gaps in a visual image to perceive them as a whole.
Eg stencils, IBM logo
Define: similarity and provide an example
Tendency to perceive similar parts of an image as being grouped together.
Eg. Uniforms, ishihara tests for colourblindness
Define: proximity and provide an example
Tendency to perceive parts of an image that are close together as being grouped together.
Eg. Constellations, where people stand at recess
Define: depth perception
Ability to use depth cues to estimate the distance of objects and to perceive the world as 3d
Define: depth cues
Cues which allow us to predict an objects location in space.
Name the monocular (state which are pictorial cues) and binocular depth cues
Binocular: convergence, retinal disparity
Monocular: accommodation, pictorial ➡️ linear perspective, interposition, texture gradient, relative size, height in the visual field
Define: pictorial cues
Visual perception cues which can be presented 2 dimensionally
Convergence: define, what do changes in tension mean, only necessary within how many metres? Example
Judging an objects location in space from the amount the eyes turn inwards.
Greater tension: closer the object, less tension: further away
Only works within 6m
Eg. If you move a pen close to your face your eyes will turn in
Define: retinal disparity, example
The slight difference between the two visual images on the two retinae (because of the 6-7cm distance between the eyes); objects location predicted by how difficult it is to combine the two images
Eg. Hold a pen in front of you closely using one eye at a time, see how much it moves
Define: accommodation,
What happens to lens when it is being viewed from closer and from far away?
The automatic adjustment of lenses to accommodate an image on the retina. allows us to estimate where an object is located in space by how much the lens bulges or elongates
Closer ➡️ bulges
Far away ➡️ lens elongates