Flashcards in Object recognition II Deck (8)
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1
Biedermann model
Proposed that we recognize objects by components, goons (geometric shapes)
critics are: how is it possible to distinguish between objects of similar shape
what are the brains mechanisms and where are the goons located?
2
Biederman on viewpoint dependent recognition
object recognition is affected by viewpoint, research shows that objects seen in less familiar viewpoints are less recognized
3
Ullmans model
explains how images/objects are segmented and how they are categorized based on visual representations (hierarchically organized)
4
Basic features of the model
highly informative pictorial fragments that are hierarchal organized
a feature is informative when it reduces uncertainty of the objects category.
informative features: need distinction and frequency
5
feature hierarchies
help to generalize objects
atomic fragments: lines, edges, corners
bottom up: incomplete information about the object
top-down segmentation: groups together different fragments and then classify it as a certain object.
6
Summary of Ullmans model
A hierarchy of abstract features continuously extracted from examples. they are usually very class-specific, non generic, and learned based on usefulness.
pros: can extract known facts of object
cons: takes a huge amount of extracting fragments
7
IT neurons
respond to pictorial objects preferentially but are not highly selective. Size and color can change.
8