3DOR 16

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https://diglib.eg.org/handle/10.2312/15070

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Browsing 3DOR 16 by Subject "and object representations"

Now showing 1 - 4 of 4
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    A Descriptor for Voxel Shapes Based on the Skeleton Cut Space
    (The Eurographics Association, 2016) Feng, Cong; Jalba, Andrei C.; Telea, Alexandru C.; A. Ferreira and A. Giachetti and D. Giorgi
    Two-dimensional medial axes and three-dimensional curve skeletons have been long used for shape retrieval tasks. In contrast, and despite their ability to fully capture shape geometry and topology, three-dimensional surface skeletons have seen much less usage in this context. We present here a framework for shape matching and retrieval based on such surface skeletons. To this end, we construct a space of cuts generated by the surface skeleton, which has desirable invariance properties with respect to shape size, rotation, translation, pose, and noise. Next, we extract a histogram-based descriptor from this cut space, and discuss three different metrics to compare such histograms for shape retrieval. We illustrate our proposal by showing our descriptor's effectiveness in shape retrieval using a known shape-database benchmark.
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    An Edit Distance for Reeb Graphs
    (The Eurographics Association, 2016) Bauer, Ulrich; Fabio, Barbara Di; Landi, Claudia; A. Ferreira and A. Giachetti and D. Giorgi
    We consider the problem of assessing the similarity of 3D shapes using Reeb graphs from the standpoint of robustness under perturbations. For this purpose, 3D objects are viewed as spaces endowed with real-valued functions, while the similarity between the resulting Reeb graphs is addressed through a graph edit distance. The cases of smooth functions on manifolds and piecewise linear functions on polyhedra stand out as the most interesting ones. The main contribution of this paper is the introduction of a general edit distance suitable for comparing Reeb graphs in these settings. This edit distance promises to be useful for applications in 3D object retrieval because of its stability properties in the presence of noise.
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    An Experimental Shape Matching Approach for Protein Docking
    (The Eurographics Association, 2016) Fernandes, Francisco; Ferreira, Alfredo; A. Ferreira and A. Giachetti and D. Giorgi
    Proteins play a vital role in biological processes, with their function being largely determined by their structure. It is important to know what a protein binds, where it binds, how it binds, and what is its final conformation. Several methodologies have been applied to solve this complex protein-protein docking problem, but the number of degrees of freedom renders this a very slow and computationally heavy challenge. To handle this problem, we propose a multi-level space partition approach to describe the three-dimensional shape of the protein. By combining two proteins in the same data structure we are able to easily detect the shape-complementary regions. Moreover, by directly integrating bio-energetic information, we can drive the algorithm by both parameters and provide a fast and efficient way to overcome some of the limitations of previous approaches.
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    Towards an Observer-oriented Theory of Shape Comparison
    (The Eurographics Association, 2016) Frosini, Patrizio; A. Ferreira and A. Giachetti and D. Giorgi
    In this position paper we suggest a possible metric approach to shape comparison that is based on a mathematical formalization of the concept of observer, seen as a collection of suitable operators acting on a metric space of functions. These functions represent the set of data that are accessible to the observer, while the operators describe the way the observer elaborates the data and enclose the invariance that he/she associates with them. We expose this model and illustrate some theoretical reasons that justify its possible use for shape comparison.