Geometric Tomography with Topological Guarantees

We consider the problem of reconstructing a compact 3-manifold (with boundary) embedded in ℝ³ from its cross-sections S with a given set of cutting planes P having arbitrary orientations. In this paper, we analyse a very natural reconstruction strategy: a point x ∈ ℝ³ belongs to the reconstructed object if (at least one of) its nearest point(s) in P belongs to S. We prove that under appropriate sampling conditions, the output of such an algorithm preserves the homotopy type of the original object. Using the homotopy equivalence, we also show that the reconstructed object is homeomorphic (and isotopic) to the original object. This is the first time that 3-dimensional shape reconstruction from cross-sections comes with theoretical guarantees.