Image-A : Applicable Mathematics in Image Engineering - 2010 - Vol. I, Nº 3
URI permanente para esta colecciónhttps://hdl.handle.net/11441/2592
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Artículo Human gait recognition using topological information(Universidad de Sevilla, 2010) Lamar León, Javier; García Reyes, Edel; González Díaz, Rocío; ; Universidad de Sevilla. Departamento de Matemática Aplicada IThis paper shows an image/video application using topological invariants in human gait recognition. The 3D volume of a gait cycle is built stacking silhouettes extracted using a background substraction approach. Ideally, the border cell complex is obtained from the 3D volume with one connected component and one cavity. Then, it is necessary to apply a topological enrichment strategy in order to obtain a robust and discriminative representation for person recognition. Using a sliding cutter plane normal to some direction of view it is possible to divide the border cell complex in different parts. The incremental algorithm is used to compute the homology on each part. A vectorial representation is built ordering the number of connected components and tunnels obtained for each cut. In order to evaluate the robustness of this representation the silhouettes were diminished to a quarter of the original size. At the same time, this is considered a simulation of a human gait captured at long distance. Even, under these difficult conditions it was possible to get a 74% of correct classification rates on CASIA-B database.Artículo Algorithm to Compute a Minimal Length Basis of Representative Cocycles of Cohomology Generators(Universidad de Sevilla, 2010) Iglesias Ham, Mabel; García Reyes, Edel; Kropatsch, Walter G.; González Díaz, Rocío; Universidad de Sevilla. Departamento de Matemática Aplicada IAn algorithm to compute a minimal length basis of representative cocycles of cohomology generators for 2D images is proposed. We based the computations on combinatorial pyramids foreseeing its future extension to 3D objects. In our research we are looking for a more refined topological description of deformable 2D and 3D shapes, than they are the often used Betti numbers. We define contractions on the object edges toward the inner of the object until the boundaries touch each other, building an irregular pyramid with this purpose. We show the possible use of the algorithm seeking the minimal cocycles that connect the convex deficiencies on a human silhouette. We used minimality in the number of cocycle edges in the basis, which is a robust description to rotations and noise.Artículo A fast algorithm to compute cohomology group generators of orientable 2-manifolds(Universidad de Sevilla, 2010) Dlotko, PawelIn this paper a fast algorithm to compute cohomology group generators of cellular decomposition of any orientable closed 2-manifold is presented. The presented algorithm is a dual version of algorithm to compute homology generators presented by David Eppstein [12] and developed by Jeff Erickson and Kim Whittlesey [13].Artículo Computing The Cubical Cohomology Ring (Extended Abstract)(Universidad de Sevilla, 2010) Kaczynski, Tomasz; Dlotko, Pawel; Mrozek, MarianThe goal of this work is to establish a new algorithm for computing the cohomology ring of cubical complexes. The cubical structure enables an explicit recurrence formula for the cup product. We derive this formula and, next, show how to extend the Mrozek and Batko [7] homology coreduction algorithm to the cohomology ring structure. The implementation of the algorithm is a work in progress. This research is aimed at applications in electromagnetism and in image processing, among other fields.Artículo Image Segmentation Inspired by Cellular Models using hardware programming(Universidad de Sevilla, 2010) Carnero Iglesias, Javier; Díaz Pernil, Daniel; Molina Abril, Helena; Real Jurado, Pedro; Universidad de Sevilla. Departamento de Matemática Aplicada ISeveral features of image segmentation make it suitable for bio–inspired techniques. It can be parallelized, locally solved and the input data can be easily encoded using representations inspired by nature. In this paper, we present a new hardware system that follows the Membrane Computing approach, and performs edge–based segmentation, noise removal and thresholding of digital images.Artículo Mereotopological Patterns for Ontology Evolution and Debugging(Universidad de Sevilla, 2010) Aranda Corral, Gonzalo A.; Borrego Díaz, Joaquín; Chávez González, Antonia María; Universidad de Sevilla. Departamento de Ciencias de la Computación e Inteligencia ArtificialIn this paper the foundational principles and the application of a mereotopological theory, the Region Connection Calculus, for controlling the revision of formal ontologies by means of visual arrangements is presented. The visual representation of logical relationships between concepts of an ontology is defined, and it is computed by means of an automated theorem prover. The user can recognize mereotopological patterns in the visual representation, particularly those representing anomalies in the ontology. An intelligent tool called Paella is designed and implemented for this task. Also, the extension to this formalism for managing uncertainty in concept reasoning is described.Artículo Gabor frames and topology-based strategies for astronomical images(Universidad de Sevilla, 2010) Onchis, Darian M.; Real Jurado, Pedro; Gillich, Gilbert-RainerThe topic of this paper is the description of procedures to remove the fringes from complicated astronomical data sets, where the interference pattern is not regular, combining topological and Gabor-based analysis. A first method is given and it involves two successive steps: first we perform an identification of the fringes using Gabor frames and latter we filter the connected components using computational topology methods. This is a new approach trying to get the benefit of filtering the harmonic representation by means of topological methods.