Gestalts
1. Find component parts
Separate from background
Figure from ground
What part of the image becomes the figure:
bounded (closed) area
symmetric area
brighter area
smaller area
convex area
meaningful
identified
near
2. Group according to built-in rules
Deciding which parts go with what objects
10 Gestalt Principles
Figure & Ground
Similarity
Angle
Form
Brightness
Proximity
Closure
Pragnanz
Good Continuation
Symmetry & Convex
Set & Context
Common Fate
Wertheimer’sPhi Phenomenon
THE THEORY
Perception is the formation of “Gestalts”
Doesn’t translate easily to English
configuration, form, holistic, structure, and pattern
Concerned with how phenomena become organized into whole meaningful figures
Visual perception is an active creation
not merely the adding up of lines and movement
3 Gestalt assumptions
1. Perceptions are formed by automatic processes
2. Perception based on wholes
3. Perceptions are integrated wholes
Problems with Gestalt theory
Gestalts are difficult to describe objectively
Gestalt formation is difficult to predict
No idea how Gestalt formation occurs
eg, built in, learned, incremental, parallel, sequential
ILLUSIONS
• False perceptions
– People don’t perceive length, area, angle, brightness they way they “should”
– Systematic perceptual errors
• Brightness contrast
Grey square on white background
• Delboeuf Illusion
Compare outer to inner
• Estimation
Height of 4-story building overestimated by 25%
Horizontal-Vertical Illusion
Impossible Objects
