publications:
- title: "Regularized Pel-Recursive Motion Estimation Using Generalized Cross-Validation and Spatial Adaptation"
  author:
  - name: "Vania Vieira Estrela"
    link: "http://academic.research.microsoft.com/Publication/584912/regularized-pel-recursive-motion-estimation-using-generalized-cross-validation-and-spatial"
  - name: "Luís Antonio Rivera"
    link: "http://academic.research.microsoft.com/Author/1161431/luis-a-rivera"
  - name: "Paulo Cesar Beggio"
    link: "http://lattes.cnpq.br/8170237658770465"
  - name: "Ricardo Tadeu Lopes"
    link: "http://academic.research.microsoft.com/Author/4751306/ricardo-tadeu-lopes"
  - name: "Vania Vieira Estrela"
    link: "http://academic.research.microsoft.com/Publication/584912/regularized-pel-recursive-motion-estimation-using-generalized-cross-validation-and-spatial"
  - name: "Ricardo Tadeu Lopes"
    link: "http://academic.research.microsoft.com/Author/4751306/ricardo-tadeu-lopes"
  - name: "Vania Vieira Estrela"
    link: "https://www.researchgate.net/profile/Vania_Estrela?ev=hdr_xprf&_sg=l2it7UJUf2g4wSUGGVaee_gK6wbXK75hN_Rt6P_99NMr2_HObKqAkOwo4ujJMZp7"
  - name: "Vania Vieira Estrela"
    link: "http://academic.research.microsoft.com/Publication/584912/regularized-pel-recursive-motion-estimation-using-generalized-cross-validation-and-spatial"
  - name: "Vania Vieira Estrela"
    link: "https://www.researchgate.net/profile/Vania_Estrela?ev=hdr_xprf&_sg=l2it7UJUf2g4wSUGGVaee_gK6wbXK75hN_Rt6P_99NMr2_HObKqAkOwo4ujJMZp7"
  - name: "Vania Vieira Estrela"
    link: "http://academic.research.microsoft.com/Author/3361386/vania-v-estrela"
  year: "2003"
  doi: "http://csdl.computer.org/comp/proceedings/sibgrapi/2003/2032/00/20320331abs.htm"
  abstract: "The computation of 2-D optical flow by means of regularized pel-recursive algorithms raises a host of issues, which include the treatment of outliers, motion discontinuities and occlusion among other problems. We propose a new approach which allows us to deal with these issues within a common framework. Our approach is based on the use of a technique called Generalized Cross-Validation to estimate the best regularization scheme for a given pixel. In our model, the regularization parameter is a matrix whose entries can account for diverse sources of error. The estimation of the motion vectors takes into consideration local properties of the image following a spatially adaptive approach where each moving pixel is supposed to have its own regularization matrix. Preliminary experiments indicate that this approach provides robust estimates of the optical flow."
  links:
    doi: "http://csdl.computer.org/comp/proceedings/sibgrapi/2003/2032/00/20320331abs.htm"
  tags:
  - " spatial adaptation"
  - " image motion estimation "
  - "2D optical flow "
  - "source-to-source"
  - "C++"
  - " generalized cross-validation technique "
  - " occlusion "
  - " regularization matrix "
  - " regularized pel-recursive algorithms "
  - "systematic-approach"
  researchr: "https://researchr.org/publication/EstrelaRBL03"
  cites: 10
  citedby: 5
  pages: "331-338"
  booktitle: "16th Brazilian Symposium on Computer Graphics and Image Processing (SIBGRAPI 2003), 12-15 October 2003, Sao Carlos, Brazil"
  publisher: "IEEE Computer Society"
  isbn: "0-7695-2032-4"
  kind: "inproceedings"
  key: "EstrelaRBL03"
- title: "Oriented Bounding Boxes Using Multiresolution Contours for Fast Interference Detection of Arbitrary Geometric Objects"
  author:
  - name: "Luís Antonio Rivera"
    link: "http://academic.research.microsoft.com/Author/1161431/luis-a-rivera"
  - name: "Vania Vieira Estrela"
    link: "http://academic.research.microsoft.com/Publication/584912/regularized-pel-recursive-motion-estimation-using-generalized-cross-validation-and-spatial"
  - name: "Paulo Cezar P. Carvalho"
    link: "http://academic.research.microsoft.com/Author/264069/paulo-cezar-pinto-carvalho"
  - name: "Vania Vieira Estrela"
    link: "http://academic.research.microsoft.com/Publication/584912/regularized-pel-recursive-motion-estimation-using-generalized-cross-validation-and-spatial"
  - name: "Vania Vieira Estrela"
    link: "https://www.researchgate.net/profile/Vania_Estrela?ev=hdr_xprf&_sg=l2it7UJUf2g4wSUGGVaee_gK6wbXK75hN_Rt6P_99NMr2_HObKqAkOwo4ujJMZp7"
  - name: "Vania Vieira Estrela"
    link: "http://academic.research.microsoft.com/Publication/584912/regularized-pel-recursive-motion-estimation-using-generalized-cross-validation-and-spatial"
  - name: "Luis Antonio Rivera"
    link: "http://academic.research.microsoft.com/Author/19802137/luis-a-river"
  year: "2004"
  abstract: "Interference detection of arbitrary geometric objects is not a trivial task due to the heavy computational load imposed by implementation issues. The hierarchically structured bounding boxes help us to quickly isolate the contour of segments in interference. In this paper, a new approach is introduced to treat the interference detection problem involving the representation of arbitrary shaped objects. Our proposed method relies upon searching for the best possible way to represent contours by means of hierarchically structured rectangular oriented bounding boxes. This technique handles 2D objects boundaries defined by closed B-spline curves with roughness details. Each oriented box is adapted and fitted to the segments of the contour using second order statistical indicators from some elements of the segments of the object contour in a multiresolution framework. Our method is efficient and robust when it comes to 2D animations in real time. It can deal with smooth curves and polygonal approximations as well results are present to illustrate the performance of the new method."
  tags:
  - "Interference Detection"
  - " Collision Detection"
  - "C++"
  - "Computação gráfica"
  - " Oriented Box"
  - "Oriented bounding box"
  - " Multiresolution Representation"
  - "systematic-approach"
  - " Bounding Box"
  researchr: "https://researchr.org/publication/RiveraEC04"
  cites: 0
  citedby: 5
  pages: "219"
  booktitle: "WSCG (Short Papers)"
  kind: "inproceedings"
  key: "RiveraEC04"
- title: "Pel-Recursive Motion Estimation Using the Expectation-Maximization Technique and Spatial Adaptation"
  author:
  - name: "Vania Vieira Estrela"
    link: "http://academic.research.microsoft.com/Publication/584912/regularized-pel-recursive-motion-estimation-using-generalized-cross-validation-and-spatial"
  - name: "Luís Antonio Rivera"
    link: "http://academic.research.microsoft.com/Author/1161431/luis-a-rivera"
  - name: "Marcos Henrique da Silva Bassani"
    link: "http://academic.research.microsoft.com/Author/42688555/m-h-da-silva-bassani"
  - name: "Vania Vieira Estrela"
    link: "http://academic.research.microsoft.com/Publication/584912/regularized-pel-recursive-motion-estimation-using-generalized-cross-validation-and-spatial"
  - name: "Vania Vieira Estrela"
    link: "http://academic.research.microsoft.com/Publication/584912/regularized-pel-recursive-motion-estimation-using-generalized-cross-validation-and-spatial"
  - name: "Marcos Henrique da Silva Bassani"
    link: "http://academic.research.microsoft.com/Author/10661924/marcos-h-s-bassani"
  - name: "Vânia Estrela"
    link: "http://br.linkedin.com/pub/vania-v-estrela/29/9bb/96b/"
  - name: "Vânia Vieira Estrela"
    link: "http://scholar.google.com/citations?hl=en&user=-ZbglqgAAAAJ&view_op=list_works&pagesize=100"
  - name: "Vania Vieira Estrela"
    link: "https://www.researchgate.net/profile/Vania_Estrela?ev=hdr_xprf&_sg=l2it7UJUf2g4wSUGGVaee_gK6wbXK75hN_Rt6P_99NMr2_HObKqAkOwo4ujJMZp7"
  - name: "Luis Antonio Rivera"
    link: "http://academic.research.microsoft.com/Author/19802137/luis-a-river"
  - name: "Luis Antonio Rivera Escriba"
    link: "http://lattes.cnpq.br/6277334830315068"
  - name: "Vania Vieira Estrela"
    link: "http://buscatextual.cnpq.br/buscatextual/visualizacv.jsp?id=K4793789Y3&mostrarNroCitacoesISI=true&mostrarNroCitacoesScopus=true&mostrarNroCitacoesScielo=true"
  - name: "Vania Vieira Estrela"
    link: "https://www.researchgate.net/profile/Vania_Estrela?ev=hdr_xprf&_sg=l2it7UJUf2g4wSUGGVaee_gK6wbXK75hN_Rt6P_99NMr2_HObKqAkOwo4ujJMZp7"
  year: "2004"
  abstract: "Pel-recursive motion estimation is a well-established approach. However, in the presence of noise, it becomes an ill-posed problem that requires regularization. In this paper, motion vectors are estimated in an iterative fashion by means of the Expectation-Maximization (EM) algorithm and a Gaussian data model. Our proposed algorithm also utilizes the local image properties of the scene to improve the motion vector estimates following a spatially adaptive approach. Numerical experiments are presented that demonstrate the merits of our methods."
  researchr: "https://researchr.org/publication/EstrelaRB04"
  cites: 9
  citedby: 0
  pages: "47-54"
  booktitle: "WSCG (Posters)"
  kind: "inproceedings"
  key: "EstrelaRB04"