# Gift-Wrapping based Preimage Computation Algorithm

2 M2DisCo - Geometry Processing and Constrained Optimization
LIRIS - Laboratoire d'InfoRmatique en Image et Systèmes d'information
Abstract : Based on a classical convex hull algorithm called Gift-Wrapping, the purpose of the paper is to provide a new algorithm for computing the vertices of a polytope called preimage - roughly the set of naive digital planes containing a finite subset $S$ of $\mathbb{Z}^3$. The vertices of the upper hemisphere, the ones of the lower hemisphere and at last the equatorial vertices are computed independently. The principle of the algorithm is based on duality and especially on the fact that the vertices of the preimage correspond to faces of the input set $S$ or of its chords set $S\ominus S \cup \{(0,0,1)\}$. It allows to go from one vertex to another by gift-wrapping until the whole region of interest has been explored.
Document type :
Journal articles
Domain :

https://hal.archives-ouvertes.fr/hal-01437609
Contributor : Équipe Gestionnaire Des Publications Si Liris <>
Submitted on : Tuesday, January 17, 2017 - 1:52:43 PM
Last modification on : Wednesday, July 8, 2020 - 12:43:33 PM

### Identifiers

• HAL Id : hal-01437609, version 1

### Citation

Yan Gerard, David Coeurjolly, F Feschet. Gift-Wrapping based Preimage Computation Algorithm. Pattern Recognition, Elsevier, 2009, 10, 42, pp.2255-2264. ⟨hal-01437609⟩

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