Topology-Guided Downsampling

We present a new downsampling method for structured volume grids, which preserves much more of the topology of a scalar field than existing downsampling methods by preferably selecting scalar values of critical points. In particular, many critical points can be preserved which are lost by traditional downsampling methods. Our method is named “topology-guided downsampling” as topology-preserving downsampling is impossible in general. However, we show that even an approximate preservation of topology is highly desirable if isosurfaces are extracted from the downsampled volume grid, e.g. for interactive previewing, because many topological features of the isosurfaces, e.g. the number of components, tunnels, and holes, are preserved. We illustrate the benefits of our method with examples from medical and technical applications of volume visualization.