Chapter 5: Perceiving Objects and Scenes Flashcards
object recognition
the process of detecting objects in an image and matching those objects to existing, stored representations of what those objects are
inverse projection problem
the task of determining the object responsible for a particular image on the retina involves starting with the retinal image and extending rays out of the eye
viewpoint invariance
the ability to recognize an object seen from different viewpoints
why is it difficult to design a perceiving machine?
The stimulus on the receptors is ambiguous
Objects can be hidden or blurred
Objects look different from different viewpoints
perceptual organization
The process by which elements in a person’s visual field become perceptually grouped and segregated to create a perception
grouping
the process by which elements are put together into coherent units
segregation
the process of separating one area or object from another
Gestalt psychologists
psychologists in the early 1900s who stated that perception is the result of perceptual organization. “the whole differs from the sum of its parts”
structuralism
a school of thought proposed by Wilhelm Wundt in 1879 that distinguished between sensations and perceptions
apparent movement
the illusion of movement
illusionary contours
contour that is perceived even though it is not present in the physical stimulus
gestalt principles
A set of principles that determine how elements in a scene become grouped together
principle of good continuation
points that when connected, result in straight or smoothly curving lines are seen as belonging together, and the lines tend to be seen in such a way as to follow the smoothest path
principle of Pragnanz (good figure)
every stimulus pattern is seen in such a way that the resulting structure is as simple as possible
principle of similarity
similar things appear to be grouped together
principle of proximity
things that are near each other appear to be grouped together
principle of common fate
things that are moving in the same direction appear to be grouped together
principle of common region
elements that are within the same region of space appear to be grouped together
principle of uniform connectedness
a connected region of the same visual properties is perceived as a single unit
what principles overpower proximity?
common region & uniform connectedness
figure-ground segregation
The division of a scene into a figure and a ground
figure
the object that stands out
ground
its background
reversible-figure-ground
a pattern that can be perceived alternatively as either a figure or a ground