Object, world and scene representations

A part of the CVonline computer vision resource summarizing the different object, world and scene representations commonly encountered in computer vision and image processing.

1. Full object representations

   1. Flat

   2. Hierarchical, by parts, structural decomposition, subcomponent representation

   3. 3D object representations

2. Functional representations

3. Geometric representation of model features

• 1. CAD representations

  2. Curve representations

     1. Chain codes

     2. Circles

     3. Conics

     4. Methods of contour integration

     5. Crack codes

     6. Curvature primal sketch

     7. Curvature scale space

     8. Cross section functions

     9. Edgelet, Contourlet

     10. Ellipse representations

     11. Intrinsic equations

     12. Line representations

     13. Line moments

     14. Phi-S curves, tangent angle functions

     15. Polyline, Polycurves, Polygonal approximations

     16. Radius vector functions

     17. Signatures

     18. Active contour models/Snakes

         1. Gradient Flow Vector (GFV) snakes

         2. Ziplock snakes

     19. Spline Representation

     20. Superellipse representations

     21. Supershapes

     22. Support functions

     23. Torsion of a curve

     24. Torsion scale space

     25. Wavelet descriptors

     26. Width functions

  3. Geometric representation of model features/Points

• • 1. Symplectic geometry

    2. Local scale descriptions

    3. Point distribution models

    4. Non-linear point distributions

    5. Surflet

• 4. Region representations

• • 1. Convex hull

    2. Region cross section functions

    3. Delaunay triangulation/Voronoi diagrams

    4. Grey-level distribution models

    5. Moments

    6. Occupancy grids

    7. Polygon mesh

    8. Trees

       1. Octrees

       2. Quadtrees

• 5. Surface representations

• • 1. Algebraic point set surfaces

    2. Conformal mapping

    3. Local point/patch representations

    4. Mean and Gaussian curvature

    5. Rubbersheeting

    6. Thin plate splines

       1. Algebraic topology

    7. Planar patches/faces, Edges, Vertices, Boundary representations

    8. Principal curvature sign classes

    9. Bézier surface

    10. Sparse grid

    11. Spherical images

    12. Subdivision surface

    13. B-spline

    14. Surface triangulation, Surface meshes

• 6. Object centered representations

• • 1. Generalized cones

    2. Geon structural description

• 7. Objects/Volume representations

• • 1. 3D skeletons

    2. Aspect graph matching

    3. Balloons

    4. Constructive solid geometry

    5. Set-theoretic modeling

    6. Spheres

       1. Surfaces of constant Gaussian curvature

       2. Schwarzschild coordinates

    7. Extended Gaussian Images

    8. Generalized cylinders

    9. Cones

    10. Medial surfaces

    11. Quadrics

    12. Hyperquadrics

    13. Superquadrics

    14. Shape histogram

• • • 1. Local Energy-based Shape Histogram (LESH)

• • 15. Spin images

• • • 1. Spherical spin images

• • 16. Spherical harmonics

    17. Supershapes

    18. Boundary representation

    19. Tetrahedral representations

    20. Volumetric frequency

    21. Voxels, Octrees

    22. Wire-frame representations

4. Logical and symbolic representations

• 1. Frames

  2. Knowledge representation

     1. Description logic

     2. KRL

  3. Predicate calculus

• • 1. Predicate logic

    2. First-order logic

• 4. Relational model

  5. Semantic nets

5. Multi-scale representation approaches

• 1. Fractals

  2. Scale space

  3. Wavelets

6. Non-rigid model representations

• 1. Active appearance models

  2. Active shape models

  3. Implicit shape models

  4. Point distribution models

  5. Deformable shapes

     1. Active contour models

     2. Deformable surfaces

     3. Deformable volumes

  6. Structural rigidity

  7. Time-varying meshes

7. Non-symbolic representations

• 1. Eigenspace representations

  2. Interest points

  3. Intrinsic images

  4. Light fields, Image-based modeling and rendering

8. Procedural representations

• 1. Production rule representations

  2. Visual routines

9. Shape classes/Shape families

10. Temporal representations

• 1. Short-term activity representations

     1. Motion history/Energy models

     2. Volume motion templates

  2. Long-term activity representations

• • 1. Global representations

       1. Hidden Markov models/Finite state models

       2. Target trajectory models

11. Types of models

• 1. Active appearance models

  2. Color appearance models

  3. Geometric models

  4. Graph models

     1. Exponential random graph models

  5. Relational models

12. Viewer centered representations, Viewpoint-dependent representations

• 1. Iconic image models

  2. Aspects/characteristic views

  3. Tesselated viewsphere approximations

     1. Geodesic domes