Catalogue of Artificial Intelligence Techniques
Author(s): H.W. Hughes
Superquadrics are a set of parameterised volumetric shapes used for computer vision applications. They are useful because a wide range of solid shapes can be generated by use of only a few parameters. Surface patches can be defined by the surface of a superquadric volume. Additionally, more complex objects can be defined by combinations of simpler volumes using union, intersection and complement. Any superquadric may be expressed by the equation:
where and , , and are the length, width and breadth respectively. and are the parameters which specify the shape of the superquadric. is the squareness parameter in the north-south direction. is the squareness parameter in the east-west direction. The advantage of this representation is that the normal vectors are given by:
enabling the shape parameters to be recovered via surface normal information from image intensity, contour shape and the like. These mathematical solids are a subset of the more general family of Generalised Cylinders.
- Barr, A.H., Superquadrics and angle-preserving transformations IEEE Computer Graphics and Applications 1, 1--20.