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Segmentation and Perceptual Grouping. (Introduction to Computer Vision, 11.1.04). Kaniza. The image of this cube contradicts the optical image. Perceptual Organization. Atomism, reductionism: Perception is a process of decomposing an image into its parts.
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Segmentation and Perceptual Grouping (Introduction to Computer Vision, 11.1.04) Kaniza
Perceptual Organization • Atomism, reductionism: • Perception is a process of decomposing an image into its parts. • The whole is equal to the sum of its parts. • Gestalt (Wertheimer, Köhler, Koffka 1912) • The whole is larger than the sum of its parts.
Proximity Gestalt Principles
Proximity Gestalt Principles • Proximity • Similarity
Proximity Similarity Gestalt Principles • Proximity • Similarity • Continuity
Closure Proximity Similarity Continuity Gestalt Principles
Proximity Similarity Continuity Closure Gestalt Principles • Closure • Common Fate
Proximity Similarity Continuity Gestalt Principles • Closure • Common Fate • Simplicity • Closure • Common Fate
Smooth Completion • Isotropic • Smoothness • Minimal curvature • Extensibility Elastica:
Elastica • Scale invariant (Weiss, Bruckstein & Netravali) • Approximation (Sharon, Brandt & Basri)
Saliency Network (Shashua & Ullman) Encourage • Length • Low curvature • Closure
Saliency Network (Shashua & Ullman)
Tensor Voting (Guy & Medioni) • Every edge element votes to all its circular edge completions • Vote attenuates with distance: e-αd • Vote attenuates with curvature: e-βk • Determine salience at every point using principal moments
Tensor Voting (Guy & Medioni)
Stochastic Completion Field (Mumford; Williams & Jacobs) • Random walk: • In addition, a particle may die with probability:
Stochastic Completion Fields (Mumford; Williams & Jacobs) • Most probable path: with
Stochastic Completion Fields (Mumford; Williams & Jacobs)
Stochastic Completion Fields (Mumford; Williams & Jacobs)
Stochastic Completion Fields (Mumford; Williams & Jacobs)
Shortest Path (Hu, Sakoda & Pavlidis)
Snakes (Kass, Witkin & Terzopolous) • Given a curve Г(s)=(x(s),y(s)), define:
Thresholding 125 156 99