Abstract
Topological simplification techniques and topology preserving compression approaches for 2D vector fields have been developed quite independently of each other. In this paper we propose a combination of both approaches: a vector field should be compressed in such a way that its important topological features (both critical points and separatrices) are preserved while its unimportant features are allowed to collapse and disappear. To do so, a number of new solutions and modi.cations of pre-existing algorithms are presented. We apply the approach to a flow data set which, is both large and topologically complex, and achieve significant compression ratios there.