Compact Sets Spline Subdivision Schemes Metric Average Minkowski Sum
Issue Date:
2002
Publisher:
Institute of Mathematics and Informatics Bulgarian Academy of Sciences
Citation:
Serdica Mathematical Journal, Vol. 28, No 4, (2002), 349p-360p
Abstract:
Attempts at extending spline subdivision schemes to operate
on compact sets are reviewed. The aim is to develop a procedure for
approximating a set-valued function with compact images from a finite set of
its samples. This is motivated by the problem of reconstructing a 3D object
from a finite set of its parallel cross sections. The first attempt is limited to
the case of convex sets, where the Minkowski sum of sets is successfully applied
to replace addition of scalars. Since for nonconvex sets the Minkowski
sum is too big and there is no approximation result as in the case of convex
sets, a binary operation, called metric average, is used instead. With the
metric average, spline subdivision schemes constitute approximating operators
for set-valued functions which are Lipschitz continuous in the Hausdorff
metric. Yet this result is not completely satisfactory, since 3D objects are
not continuous in the Hausdorff metric near points of change of topology,
and a special treatment near such points has yet to be designed.
Description:
Dedicated to the memory of our colleague Vasil Popov January 14, 1942 – May 31, 1990
* Partially supported by ISF-Center of Excellence, and by The Hermann Minkowski Center for Geometry at Tel Aviv University, Israel