Image-A : Applicable Mathematics in Image Engineering - 2013 - Vol. III, Nº 6

URI permanente para esta colecciónhttps://hdl.handle.net/11441/2595

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  • Miniatura
    Acceso AbiertoArtículo
    Interactive display of 2D and 3D discrete quadrics with controlled topology
    (Universidad de Sevilla, 2013) Andres, Eric; Toutant, Jean-Luc
    In this demonstration, we are going to propose an interactive animation of analytically defined discrete conics (quadrics in 2D) and discrete quadrics in 3D. The digitization is performed on the 2D quadratic equation: Ax2 + Bxy + Cy2 + Dx + Ey + F = 0 and the 3D quadric equation Ax2 + By2 + Cz2 + Dxy + Exz + F yz + Gx + Hy + Iz + J = 0.We propose 4 and 8-connected discrete 2D conics (naive and standard discrete conics) defined analytically where the user can see the resulting discrete conic while interacting with the parameters A, B, C, D, E and F. In the same way, we propose 6-separating and tunnel free 3D quadrics (naive and standard 3D quadrics) defined analytically where the user can can interactively modify the parameters A, B, C, D, E, F, G, H, I and J.
  • Miniatura
    Acceso AbiertoArtículo
    Distributed boundary tracking using alpha and Delaunay-Cech shapes
    (Universidad de Sevilla, 2013) Chintakunta, Harish; Krim, Hamid
    We demonstrate real time tracking of systematic failures in sensor networks, using distributed computation of the α−shape derived from the network. More generally, our work may be applied to tracking the boundary of any time varying object, whose data is captured in the form of a point cloud. We also demonstrate the use of a new geometric object called the Delaunay-Cech shape, which is geometrically more appropriate than an ˇ α−shape for some cases. For a given point set S in a plane, we develop a distributed algorithm to compute the α−shape of S. α−shapes are well known geometric objects which generalize the idea of a convex hull, and provide a good definition for the shape of S. We assume that the distances between pairs of points which are closer than a certain distance r > 0 are provided, and we show constructively that this information is sufficient to compute the alpha shapes for a range of parameters, where the range depends on r.
  • Miniatura
    Acceso AbiertoArtículo
    Bioinspired parallel 2D or 3D skeletonization
    (Universidad de Sevilla, 2013) Reina Molina, Raúl; Díaz Pernil, Daniel; Universidad de Sevilla. Departamento de Matemática Aplicada I
    Algebraic Topology has been proved to be an useful tool to be used in image processing. In this case we will borrow some elements from Algebraic Topology in order to show a parallel algorithm for thinning a binary 3D image respecting its shape information. The parallelization of the thinning algorithm is based on Membrane Computing. This research area has already been proved to be useful in the development of parallel image processing algorithms. We present here the main guidelines of the algorithms along with a slight introduction about some basic required knowledge about Algebraic Topology and Membrane Computing.
  • Miniatura
    Acceso AbiertoArtículo
    Software tool for contrast enhancement and segmentation of melanoma images based on human perception
    (Universidad de Sevilla, 2013) Fondón García, Irene; Abbas, Qaisar; Celebi, M. Emre; Ahmad, Waqar; Mushtaq, Qaisar; Universidad de Sevilla. Departamento de Teoría de la Señal y Comunicaciones
    In this paper we present a software tool for melanoma border detection (MBD). It has been designed to be incorporated in any Computer Aided Diagnosis Tool (CAD) for early detection of melanoma in mass screening programs. The tool is completely automatic, posses a user-friendly interface and does not require any specific hardware. The main steps followed by the implemented algorithm are: uneven illumination correction, color contrast improvement and color image segmentation. All of them are performed in the uniform color space CIE L * a * b * in order to achieve a complete adaptation to human color perception. The program is able to provide not only the final obtained segmentation result but also intermediate graphical outcomes, guiding the user in the process of melanoma detection. This simple, friendly but powerful interface can serve as a support for the medical personnel in the melanoma diagnostic process. The MBD software and some samples of the dermoscopy images used can be downloaded at http://cs.ntu. edu.pk/research.php.
  • Miniatura
    Acceso AbiertoArtículo
    An application for gait recognition using persistent homology
    (Universidad de Sevilla, 2013) Lamar León, Javier; García Reyes, Edel; González Díaz, Rocío; Alonso Baryolo, Raúl; Universidad de Sevilla. Departamento de Matemática Aplicada I
    This Demo presents an application for gait recognition using persistent homology. Using a background subtraction approach, a silhouette sequence is obtained from a camera in a controlled environment. A border simplicial complex is built stacking silhouettes aligned by their gravity center. A multifiltration is applied on the border simplicial complex which captures relations among the parts of the human body when walking. Finally, the topological gait signature is extracted from the persistence barcode according to each filtration. The measure cosine is used to give a similarity value between topological signatures. The input of this Demo are videos with resolution 320x240 to 25f ps. The videos in CASIA-B database are used to prove the efficacy and efficiency. A computer with 2Gb of RAM memory and a DualCore processor was used to test the implementation of the proposed algorithm. In this Demo all related tasks have been programmed by the authors in the C++ programming language. OpenCV library has been used for the image processing part.