What is a (visual) feature?

''What is a Feature? A Fast and Frugal Approach to the Study of Visual Properties
Perceptual systems, both biological and artificial, are broadly speaking systems that can extract certain features from a sensory array and use these features for categorisation tasks, recognition and motor control. Several characterisations of the notion of ‘feature’ have been proposed so far in specific fields of vision science. Yet, a general account and tentative classification of what counts as a ‘good’ visual feature is still missing.
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The heuristics-based approach is promising in providing a
framework for dealing with cognitive capacities that are relevant for specific environmental settings.
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