Reassembling fractured objects by geometric matching

International Journal of Computer Vision, 2008

We propose a novel and efficient surface matching approach for reassembling broken solids as well as for matching assembly components using cluster trees of oriented points. The method rapidly scans through the space of all possible contact poses of the fragments to be (re)assembled using a tree search strategy, which neither relies on any surface features nor requires an initial solution. The new method first decomposes each point set into a binary tree structure using a hierarchical clustering algorithm. Subsequently the fragments are matched pairwise by descending the cluster trees simultaneously in a depth-first fashion. In contrast to the reassemblage of pottery and thin walled artifacts, this paper addresses the problem of matching broken 3D solids on the basis of their 2.5D fracture surfaces, which are assumed to be reasonable large. Our proposed contact area maximization is a powerful common basis for most surface matching tasks, which can be adapted to numerous special applications. The suggested approach is very robust and offers an outstanding efficiency.

Lecture Notes in Computer Science, 2004

This paper proposes an efficient pairwise surface matching approach for the automatic assembly of 3d fragments or industrial components. The method rapidly scans through the space of all possible solutions by a special kind of random sample consensus (RANSAC) scheme. By using surface normals and optionally simple features like surface curvatures, we can highly constrain the initial 6 degrees of freedom search space of all relative transformations between two fragments. The suggested approach is robust, very time and memory efficient, easy to implement and applicable to all kinds of surface data where surface normals are available (e.g. range images, polygonal object representations, point clouds with neighbor connectivity, etc.).

10th International Conference on Pattern Recognition Systems (ICPRS-2019), 2019

This work presents our results on reassembly of broken objects using a newly developed fragment topology and feature extraction methodology. The reassembly of broken objects is a common problem in different domains including computer-aided bone fracture reduction [1] and reassembly of broken artefacts [2]. The new fragment topology combines information from intact and fractured region boundaries to reduce possible correspondences between the fragments and optimise our iterative matching process. Experiments performed on different multifragment objects show that the proposed topology can be effectively applied, completing the process in a small number of iterations and with average alignment error 0.12mm.

… of Computer Vision, …, 2007

We propose a novel framework for 3D reassembly, the task of assembling a solid object from its broken pieces. The primary challenge in this under-explored problem is to robustly establish compatibility between parts from one object. Feature-based techniques have shown success in domains such as 3D similarity search; unfortunately, the global features typically employed to quantify whole-object similarity are unsuitable for identifying part-level compatibility. Therefore, we propose the use of local features which, in conjunction with robust matching, have become popular for object recognition in 2D images. This paper demonstrates that an analogous framework can be successful for 3D reassembly. Automating part-level compatibility enables the construction of an interactive system for 3D reassembly, where the user can easily assemble a desired object from a large collection of pieces (many of which are irrelevant) by iteratively selecting compatible parts. We evaluate our approach on a simulated database of broken objects and show that it scales well in the presence of noise and extraneous pieces.

2003 Conference on Computer Vision and Pattern Recognition Workshop, 2003

In the recent past, fragment matching has been treated in two different approaches, one using curve matching methods and one that compares whole surfaces or volumes, depending on the nature of the broken artefacts. Presented here is a fast, unified method that combines curve matching techniques with a surface matching algorithm to estimate the positioning and respective matching error for the joining of three-dimensional fragmented objects. Combining both aspects of fragment matching, essentially eliminates most of the ambiguities present in each one of the matching problem categories and helps provide more accurate results with low computational cost.

IEEE Transactions on Pattern Analysis and Machine Intelligence, 2002

The problem of reassembling an object from its parts or fragments has never been addressed with a unified computational approach, which depends on the pure geometric form of the parts and not application-specific features. We propose a method for the automatic reconstruction of a model based on the geometry of its parts, which may be computer-generated models or range-scanned models. The matching process can benefit from any other external constraint imposed by the specific application.

2017

Virtual reassembly problems are often encountered in the cultural heritage domain. The reassembly or "puzzling" problem is typically described as the process for the identification of corresponding pieces within a part collection, followed by the clustering and pose estimation of multiple parts that result in a virtual representation of assembled objects. This work addresses this problem with an efficient, user-guided computational approach. The proposed approach augments the typical reassembly pipeline with a smart culling step, where geometrically incompatible fragment combinations can be quickly rejected. After splitting each fragment into potentially fractured and intact facets, each intact facet is examined for prominent linear or curved structures and a heuristic test is employed to evaluate the plausibility of facet pairs, by comparing the number of feature curves associated with each facet, as well as the geometric texture of associated intact surfaces. This test excludes many pairwise combinations from the remaining part of the reassembly process, significantly reducing overall time cost. For all facet pairs that pass the initial plausibility test, pairwise registration driven by enhanced simulated annealing is applied, followed by multipart registration. The proposed reassembly approach is evaluated on real scanned data and our experiments demonstrate an increase in efficiency that ranges from 30% to more than 500% in some cases, depending on the number of culled combinations. CCS Concepts •Computing methodologies → Shape analysis; •Applied computing → Arts and humanities;

British Machine Vision Conference, 2000

We describe here an efficient algorithm for re-assembling one or more un- known objects that have been broken or torn into a large number of ir- regular fragments—a problem that often arises in achaeology, art restora- tion, forensics, and other disciplines. The algorithm compares the curvature- encoded fragment outlines, using a modified dynamic programming sequence- matching algorithm, at progressively increasing

IEEE Transactions on Pattern Analysis and Machine Intelligence, 2002

AbstractÐWe describe here an efficient procedure for reassembling unknown two-dimensional objects that have been broken or torn into a large number of irregular fragmentsÐa problem that often arises in archaeology, art restoration, forensics, and other disciplines. The procedure compares the curvature-encoded fragment outlines, at progressively increasing scales of resolution, using an incremental dynamic programming sequence-matching algorithm. The total cost gets reduced by a factor proportional to the mean number of samples per segment, which makes the method viable for problems of practical size (thousands of fragments). The performance of our method is illustrated with an artificial but realistic example.

1997

The problem of reconstruction of broken surface objects embedded in 3-D space is handled. A coordinate independent representation for the crack curves is developed. A new robust matching algorithm is proposed which serves for nding matching pieces even when some brittle pieces are missing.