Object Completion using k-Sparse Optimization

Pavlos Mavridis1       Ivan Sipiran2       Anthousis Andreadis1       Georgios Papaioannou1
1 Department of Informatics, Athens University of Economics and Business
2 Sección Ingeniería Informática, Pontificia Universidad Católica del Perú PUCP
Computer Graphics Forum (Proceedings of Pacific Graphics 2015), Volume 34, Number 7, October 2015

automatic completion results
Figure 1. Completion of various partial objects using our method. The insets show the partial input shapes.


We present a new method for the completion of partial globally-symmetric 3D objects, based on the detection of partial and approximate symmetries in the incomplete input dataset. In our approach, symmetry detection is formulated as a constrained sparsity maximization problem, which is solved efficiently using a robust RANSAC-based optimizer. The detected partial symmetries are then reused iteratively, in order to complete the missing parts of the object. A global error relaxation method minimizes the accumulated alignment errors and a non-rigid registration approach applies local deformations in order to properly handle approximate symmetry. Unlike previous approaches, our method does not rely on the computation of features, it uniformly handles translational, rotational and reflectional symmetries and can provide plausible object completion results, even on challenging cases, where more than half of the target object is missing. We demonstrate our algorithm in the completion of 3D scans with varying levels of partiality and we show the applicability of our approach in the repair and completion of heavily eroded or incomplete cultural heritage objects.

Supplemental Images

automatic completion results
Figure 2. Our method successfully detects the underlying discrete rotational symmetry of this cultural heritage object and iteratively completes the missing parts.


This work has received funding from the European Union's Seventh Framework Programme for research, technological development and demonstration under grant agreement No. 600533.


@article {Mavridis:2015d,
author = {Mavridis, P. and Sipiran, I. and Andreadis, A. and Papaioannou, G.},
title = {Object Completion using k-Sparse Optimization},
journal = {Computer Graphics Forum},
volume = {34},
number = {7},
issn = {1467-8659},
doi = {10.1111/cgf.12741},
pages = {13--21},
year = {2015},