DSpace Komunita:http://hdl.handle.net/11025/12542024-03-28T19:17:34Z2024-03-28T19:17:34ZParametric Curves Variations with Respect to a Given DirectionBayar, AbdelouahadSami, Khalidhttp://hdl.handle.net/11025/154442021-09-22T09:00:00Z2010-01-01T00:00:00ZNázev: Parametric Curves Variations with Respect to a Given Direction
Autoři: Bayar, Abdelouahad; Sami, Khalid
Editoři: Skala, Václav
Abstrakt: Modeling dynamic characters, in observance of calligraphic rules can be done with the help of parametric
curves. The class of Bézier curves is a powerful tool for modeling the outlines of the surface razed by a nib's
calligrapher. Unfortunately, after capturing the character's hand-drawn outlines, the surface delimited
by the outlines doesn't correspond to the space to shade when writing the character. Some of the curves
pieces of the outlines are to be subdivided at some appropriate points. In order to identify these points,
decompositions of the Bézier curves involved, with respect to particular directions, are necessary. This
paper presents a simple and e ective mathematical method for doing such decompositions.The proposed
method helps to determine the points as extrema of certain functions. Then, the method is implemented
and used to design some Arabic dynamical characters. This will help in building dynamic fonts respecting
calligraphic strong rules.2010-01-01T00:00:00ZBayar, AbdelouahadSami, KhalidPartial 3D shape matching using large fat tetrahedronsVergeest, Joris S. M.Kooijman, A.Song, Y.http://hdl.handle.net/11025/12722021-09-22T09:00:00Z2010-01-01T00:00:00ZNázev: Partial 3D shape matching using large fat tetrahedrons
Autoři: Vergeest, Joris S. M.; Kooijman, A.; Song, Y.
Editoři: Skala, Václav
Abstrakt: We present a method of automatic alignment of two partially matching 3D shapes. The algorithm selects large fat
tetrahedrons (LFT) composed of 4 vertices in one shape and exhaustively searches in the other shape for sets of 4
vertices being compatible with the tetrahedron. By selecting such salient tetrahedrons that are relatively wide and
fat, although also being not too unlikely to be contained in the overlap region, the cost of search can be reduced.
The method is relatively insensitive to noise and not depending on the existence of local shape features nor on
feature correspondences. When implemented on a GPU in Cuda, two point sets of 40,000 each can be aligned
within seconds. The method is intended to support interactive 3D scan registration applications.2010-01-01T00:00:00ZVergeest, Joris S. M.Kooijman, A.Song, Y.Simulating real-time cloth with adaptive edge-basedSimnett, T. J. R.Laycock, R. G.Day, A. M.http://hdl.handle.net/11025/12712021-09-22T09:00:00Z2010-01-01T00:00:00ZNázev: Simulating real-time cloth with adaptive edge-based
Autoři: Simnett, T. J. R.; Laycock, R. G.; Day, A. M.
Editoři: Skala, Václav
Abstrakt: We present an approach to simulating detailed cloth in real-time using an adaptive edge-based mesh, by enhancing
its usability and performance. We show how simple seaming can be used to combine multiple adaptive meshes into
garments, accomplished with the use of discontinuous material co-ordinates. Performance is improved by decoupling
the mesh adaption and simulation steps, allowing efficient data structures to be exploited for the simulation
and collision detection. Greater memory efficiency is achieved by pre-allocating a pool of memory to be used by
any mesh at any hierarchical level. The collision detection process is integrated into the edge-based adaption technique,
enabling a garment to be coarsened and refined repeatedly, such that no new vertices are created inside of
the object in collision. Our technique is illustrated for a 67k triangle character wearing a T-shirt adaptively refined
to 6k triangles in real-time.2010-01-01T00:00:00ZSimnett, T. J. R.Laycock, R. G.Day, A. M.A new CBIR approach based on relevance feedback and optimum-path forest classificationda Silva, André TavaresXavier, AlexandreMagalhães, Léo Pinihttp://hdl.handle.net/11025/12702021-09-22T09:00:00Z2010-01-01T00:00:00ZNázev: A new CBIR approach based on relevance feedback and optimum-path forest classification
Autoři: da Silva, André Tavares; Xavier, Alexandre; Magalhães, Léo Pini
Editoři: Skala, Václav
Abstrakt: Recently some CBIR approaches have shown the use of relevance feedback to train a pattern classifier to select relevant images
for retrieval. This paper revisits this strategy by using an optimum-path forest (OPF) classifier. During relevance feedback
iterations, the proposed method uses the OPF classifier to decide which database images are relevant or not. Images classified
as relevant are sorted and presented to the user for a new iteration. Such images are ordered according to the normalized
distance using relevant and irrelevant representative images, computed previously by the OPF classifier. Our experiments show
that the proposed approach requires fewer iterations, being faster and more effective than methods based on SVM.2010-01-01T00:00:00Zda Silva, André TavaresXavier, AlexandreMagalhães, Léo Pini