This paper discusses region-based representations useful to create connected operators. The filtering approach involves three steps: first, a region tree representation of the input image is constructed. Second, the simplification is obtained by pruning the tree and third, and output image is constructed from the pruned tree. The paper focuses in particular on the pruning strategies that can be...

This paper discusses region-based representations useful to create connected operators. The filtering approach involves three steps: first, a region tree representation of the input image is constructed. Second, the simplification is obtained by pruning the tree and third, and output image is constructed from the pruned tree. The paper focuses in particular on several pruning strategies that ca...

We consider the descriptive complexity of some subsets of the infinite permutation group S∞ which arise naturally from the classical series rearrangement theorems of Riemann, Levy, and Steinitz. In particular, given some fixed conditionally convergent series of vectors in Euclidean space Rd, we study the set of permutations which make the series diverge, as well as the set of permutations which...