Use este identificador para citar ou linkar para este item:
http://www.repositorio.ufop.br/jspui/handle/123456789/1265
Título: | Comparing curvature estimation techniques. |
Autor(es): | Estrozi, Leandro Farias Bianchi, Andrea Gomes Campos Rios Filho, Luiz Gonzaga César Júnior, Roberto Marcondes Costa, Luciano da Fontoura |
Palavras-chave: | Performance evaluation Fourier transform Differential geometry Numerical techniques Cuvature estimation |
Data do documento: | 1999 |
Referência: | ESTROZI, L. F. et al. Comparing curvature estimation techniques. In: SBAI - Simpósio Brasileiro de Automação Inteligente, 1999, São Paulo, p.1-6. Disponível em: <http://www.ime.usp.br/~cesar/publications/sbai99/sbai99.pdf>. Acesso em: 08 ago. 2012. |
Resumo: | This article presents a careful comparative evaluation of two techniques for numerical curvature estimation of 2D closed contours (more specifically closed, regular and simple parametric curves). The considered methods are: (a) a 1-D Fourier-based approach; and (b) a 2-D Fourier-based approach involving the embedding of the contour into a 2-D regular surface (presented for the first time in this article). Both these techniques employ Gaussian smoothing as a regularizing condition in order to estimate the first and second derivatives needed for curvature estimation. These methods are considered according to a multiresolution approach, where the standard deviation of the Gaussians are used as scale parameters. The methods are applied to a standard set of curves whose analytical curvatures are known in order to estimate and compare the errors of the numerical approaches. Three kinds of parametric curves are considered: (i) curves with analytical description; (ii) curves synthesized in terms of Fourier components of curvature; and (iii) curves obtained by splines. A precise comparison methodology is devised which includes the adoption of a common spatial quantization approach (namely square box quantization) and the explicit consideration of the influence of the related smoothing parameters. The obtained results indicate that the 1- D approach is not only faster, but also more accurate. However, the 2-D approach is still interesting and reasonably accurate for applications in situations where the curvature along the whole 2-D domains is needed. |
URI: | http://www.repositorio.ufop.br/handle/123456789/1265 |
Aparece nas coleções: | DEFIS - Trabalhos apresentados em eventos |
Arquivos associados a este item:
Arquivo | Descrição | Tamanho | Formato | |
---|---|---|---|---|
EVENTO_ComparingCurvatureEstimation.pdf | 728,05 kB | Adobe PDF | Visualizar/Abrir |
Os itens no repositório estão protegidos por copyright, com todos os direitos reservados, salvo quando é indicado o contrário.