Browsing by Author "Gomes, Abel J.P."

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    Part‐Based Mesh Segmentation: A Survey
    (© 2018 The Eurographics Association and John Wiley & Sons Ltd., 2018) Rodrigues, Rui S. V.; Morgado, José F. M.; Gomes, Abel J. P.; Chen, Min and Benes, Bedrich
    This paper surveys mesh segmentation techniques and algorithms, with a focus on part‐based segmentation, that is, segmentation that divides a mesh (featuring a 3D object) into meaningful parts. Part‐based segmentation applies to a single object and also to a family of objects (i.e. co‐segmentation). However, we shall not address here chart‐based segmentation, though some mesh co‐segmentation methods employ such chart‐based segmentation in the initial step of their pipeline. Finally, the taxonomy proposed in this paper is new in the sense that one classifies each segmentation algorithm regarding the dimension (i.e. 1D, 2D and 3D) of the representation of object parts. The leading idea behind this survey is to identify the properties and limitations of the state‐of‐the‐art algorithms to shed light on the challenges for future work.This paper surveys mesh segmentation techniques and algorithms, with a focus on part‐based segmentation, that is, segmentation that divides a mesh (featuring a 3D object) into meaningful parts. Part‐based segmentation applies to a single object and also to a family of objects (i.e. co‐segmentation). However, we shall not address here chart‐based segmentation, though some mesh co‐segmentation methods employ such chart‐based segmentation in the initial step of their pipeline. Finally, the taxonomy proposed in this paper is new in the sense that one classifies each segmentation algorithm regarding the dimension (i.e. 1D, 2D and 3D) of the representation of object parts. The leading idea behind this survey is to identify the properties and limitations of the state‐of‐the‐art algorithms to shed light on the challenges for future work.
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    Segmentação de Malhas Triangulares baseada em Convexidade Relaxada
    (The Eurographics Association, 2020) Rodrigues, Rui Sérgio; Morgado, José Francisco; Gomes, Abel J. P.; Goncalves, Alexandrino and Fernandes, Antonio Ramires and Rodrigues, Nuno
    Este artigo introduz uma nova técnica de segmentação de malhas triangulares, designada por segmentação de montes e vales (MeV), que combina técnicas de segmentação baseadas na fronteira e no interior de regiões. O algoritmo MeV usa uma função altura com sinal com o objectivo de distinguir entre montes (+) e vales (-) e zonas planares (0). Cada região é construída á volta de extremos locais (i.e., máximos e mínimos) da malha. Um monte é construído a partir de um máximo e um vale a partir de um mínimo. No entanto, é possível ás fronteiras dos montes invadirem parcialmente os vales e vice-versa. Consequentemente, vamos ter montes que formam regiões convexas relaxadas e vales que formam regiões cˆoncavas relaxadas. Ao contrário do actual estado da arte da segmentação de malhas, a existência destas regiões relaxadas torna o algoritmo eficaz na segmentação de diferentes tipos de objectos (de forma livre ou não).