Contour Nest: A Two-dimensional Representation for Three-dimensional Isosurfaces

Abstract

Visualization of the topological structure of isosurfaces such as exclusion and inclusion plays an important role in analyzing three-dimensional (3D) scalar data like medical images, especially in selecting isosurfaces to observe. Under certain conditions, all isosurfaces in a 3D scalar field are closed surfaces having nest structure. Our purpose here is to translate closed isosurfaces in 3D space as a nest structure. Contour Tree (CT) can describe the nest structure among isosurfaces by tree structure, but it is difficult for users to understand the nest structure by direct observation of the tree shape. In this report, we propose a two-dimensional (2D) representation procedure named Contour Nest (CN) for intuitive display of the nest structure of isosurfaces. In the proposed method, nest structure of 3D isosurfaces extracted by Contour Tree is represented as 2D nest of rectangles. We have evaluated the effectiveness of the proposed method in selecting 3D isosurfaces.