Shape Reconstruction - Application to Geology

Several methods based on the use of Voronoi diagrams, are proposed for the 3D and 2D reconstruction of natural objects. The main application domain is geology. A first algorithm enables volumes to be constructed starting from the combined use of geological maps, cross-sections and drill-lines. Input data have associated colors (object characteristics), but may be sparse and heterogeneous, and do not need to be organized in any special way. The method is based on Voronoi diagrams and produces volumes. Attributing colors to data allows to reconstruct simultaneously objects that are known to be distinct. Our reconstruction method is based on "proximity" and therefore uses Voronoi diagrams. For simplicity, the heterogeneous data set S (points, lines, surfaces) is discretized into a set of colored points Sd. The "colored" Voronoi diagram of Sd. gives a partition of the space into regions R, which approximates the scene. In Addition, we smooth the boundaries of the regions of R, in such a way that the topology of the Voronoi regions is preserved, i.e. each new deformed region contains the same set of points as initially. Specific methods are added to allow the insertion of faults in the reconstruction process. We propose an other way for representing reconstructed objects, using the combination of implicit functions, Voronoi diagrams and nearest neighbor interpolation. The goal of the method is to define a continuous and smooth function f, so that f=0 approximates the expected shape. We define local functions in the neighborhood of the initial data, and the final shape results in interpolating those functions.

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Additional Info

Field Value
Source https://theses.hal.science/tel-00832483
Author Nullans, Stéphane
Maintainer CCSD
Last Updated May 10, 2026, 19:01 (UTC)
Created May 10, 2026, 19:01 (UTC)
Identifier tel-00832483
Language fr
Rights https://about.hal.science/hal-authorisation-v1/
contributor Geometry, Algorithms and Robotics (PRISME) ; Centre Inria d'Université Côte d'Azur ; Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)
creator Nullans, Stéphane
date 1998-12-14T00:00:00
harvest_object_id aec762f8-98c2-4e12-b285-fe1e8a9973b9
harvest_source_id 3374d638-d20b-4672-ba96-a23232d55657
harvest_source_title test moissonnage SELUNE
metadata_modified 2025-08-26T00:00:00
set_spec type:THESE