Título: | AN ALGORITHM FOR CURVE RECONSTRUCTION FROM SPARSE POINTS | ||||||||||||||||||||||||||||||||||||||||
Autor: |
CRISTIANE AZEVEDO FERREIRA |
||||||||||||||||||||||||||||||||||||||||
Colaborador(es): |
HELIO CORTES VIEIRA LOPES - Orientador |
||||||||||||||||||||||||||||||||||||||||
Catalogação: | 23/JAN/2004 | Língua(s): | PORTUGUESE - BRAZIL |
||||||||||||||||||||||||||||||||||||||
Tipo: | TEXT | Subtipo: | THESIS | ||||||||||||||||||||||||||||||||||||||
Notas: |
[pt] Todos os dados constantes dos documentos são de inteira responsabilidade de seus autores. Os dados utilizados nas descrições dos documentos estão em conformidade com os sistemas da administração da PUC-Rio. [en] All data contained in the documents are the sole responsibility of the authors. The data used in the descriptions of the documents are in conformity with the systems of the administration of PUC-Rio. |
||||||||||||||||||||||||||||||||||||||||
Referência(s): |
[pt] https://www.maxwell.vrac.puc-rio.br/projetosEspeciais/ETDs/consultas/conteudo.php?strSecao=resultado&nrSeq=4430&idi=1 [en] https://www.maxwell.vrac.puc-rio.br/projetosEspeciais/ETDs/consultas/conteudo.php?strSecao=resultado&nrSeq=4430&idi=2 |
||||||||||||||||||||||||||||||||||||||||
DOI: | https://doi.org/10.17771/PUCRio.acad.4430 | ||||||||||||||||||||||||||||||||||||||||
Resumo: | |||||||||||||||||||||||||||||||||||||||||
Curve and surface reconstruction from sparse data has been
recognized as an important problem in computer graphics.
Non structured data points (i.e., a set of points with no
knowledge of connectivity and proximity) together with
the existence of noise make this problem quite difficult.
In order to solve it, several techniques have been
proposed, such as, some of them are based on Delaunay
triangulation, other are based on implicit surface
reconstruction or on the advancing front techniques. Our
algorithm consists basically in four steps. In the first
step, a clustering procedure is performed in order to group
the sample points according to their spatial location. This
procedure obtains an spatial structure for the points by
subdividing uniformly the plane in rectangular cells, and
classifying them into two categories: empty (when the cell
contains no point inside) or not empty (otherwise). At this
stage, a data structure is built in such way that it is
possible to query the set of sample points that belong to a
given rectangular cell. The second step processes the point
through the Moving Least Squares method. Its objective
is not only to reduce the noise on the data, but also to
adapt the number of point to the desired level, by adding
or removing points from the initial set. The third step
builds the skeleton of the set of cells that have sample
point on its interior. Such skeleton is in fact a digital
approximation for the curve that will be reconstructed. It
is obtained by the use of a topological thinning algorithm,
and its implementation is done in such a way that the
number of points in each cell is considered, for example,
the cells with less number of points are not considered for
the thinning. In the last step, the curve is finally
reconstructed To do so, the skeleton obtained in the third
step is used to construct a piecewise-linear approximation
for the curve, where each vertex is obtained from the MLS
projection on the middle point of the skeleton rectangular
cell.
|
|||||||||||||||||||||||||||||||||||||||||
|