Abstract

Most vision research is based on pointwise image formation physics. People, however, require more than such local information and are strikingly insensitive to reflectance function, etc. People depend on large-scale structure to guide their perceptual interpretation; general-purpose vision seems, therefore, to require a representation capable of describing such structure. We present a representation that has proved competent to accurately describe natural and man-made forms in a succinct and psychologically natural manner. Superquadrics, a superset of traditional modeling primitives, are the basic element in this representation. These primitives are then deformed by stretching, bending, or tapering and combined using Boolean operations to recursively form new, complex primitives that may again be deformed and combined. This representation has great power and efficiency: the human body (including face and hands) requires combination of only 40 primitives, fewer than 300 bytes of information. Fractallike forms (e.g., clouds, mountains) may be described in a perceptually natural manner as the recursive sum of primitives of decreasing size. Such descriptions must be recoverable from image data, which is primarily a function of the surface's normal vector. Because the vector function describing a superquadric’s surface shape is dual to that of its surface normal we can, given only the tilt component of a few surface normals, recover the desired shape description.

© 1985 Optical Society of America