Object recognition Flashcards
Main sense used in research? And how much? (neurons)
Visual - 50% of neurons in cortex
List some sensory receptors (thermal…)
thermal - chemical - photo - mechanical
Using top-down, how is perception created by our own experiences?
Our experiences interact with info and make our expectations - perception is created by the brain
How does the visual processing system work for perception? (sensory input…)
Brain receives sensory input - perceives the object
Picture comes through lens - lens inverts it - back of retina
What happens to each eye? (vf/h…)
Each eye is split into different visual fields - which are processed using different hemispheres
What are the three stages of object recognition?
- local features
- shape representation
- object representation
Definitions of each stage?
- local features - detecting edge/contrast
- shape representation - gestalt principles
- object representation - stored knowledge
Gestalt principles - what does image organisation refer to?
Components of an image based on visual properties are grouped together
List some organisation laws that help ‘illusory contours’ (similarity…)
similarity, proximity, closure, good continuation
What are illusory contours?
Eg. with good continuation - seeing ‘curves’ in a visual illusory task that aren’t actually there - the way the image has been made tricks you into seeing things
Marr… shape perception (ps…)?
Marr - bottom-up sketches produce a primal sketch
Primitives
edges/lengths/colours etc…
What’s template matching?
Mental images - internal representation of object recognition/visual input - used with computers
What’s feature analysis?
Observing characteristics of everything (people, patterns) - usually low level ones first - 3D
Biederman 1987 - what are geons?
3D shapes/views allow object recognition - removing colours and termination points of shapes makes this harder
