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XII Brazilian Symposium on Computer Graphics and Image Processing (Cat. No.PR00481)

17-20 Oct. 1999

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  • XII Brazilian Symposium on Computer Graphics and Image Processing (Cat. No.PR00481)

    Publication Year: 1999
    Request permission for commercial reuse | PDF file iconPDF (202 KB)
    Freely Available from IEEE
  • Anno 2010-remembering our future. Challenges and frontiers of visualization for Human-Media Technology as the kernel for Human-Centered Computing

    Publication Year: 1999
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (6 KB)

    Summary form only given. Human-Media-Technology is one of the "technology's top 10 challenges and opportunities" for the year 2010. The subject hereby is: "humans live, science finds out how technology conforms." The goal is to develop environments that allow users to cooperate in the most efficient and natural way. Human-centered systems will have to incorporate people as an explicit design compo... View full abstract»

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  • Characterization of linear and morphological operators

    Publication Year: 1999
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (4 KB)

    Summary form only given, as follows. In image processing, the transformations of an image to another one are obtained through operators. Among the most important operators are the linear operators and the morphological ones (dilations and erosions). We recall the definition of these operators and present an algebraic characterization of them for the case of spatial invariance. The importance of th... View full abstract»

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  • Accurate building structure recovery from aerial imagery

    Publication Year: 1999
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (3 KB)

    Summary form only given, as follows. In this paper, we discuss methods for the detection and reconstruction of buildings from aerial imagery. These methods have been intended for the analysis of urban and suburban areas and have been applied to images of different resolutions (between 1 m and 10 cm per pixel). Various algorithms for image matching have been investigated, including hierarchical pro... View full abstract»

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  • Index of authors

    Publication Year: 1999, Page(s): 357
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    Freely Available from IEEE
  • Using adaptive contraction for fractal image coding based on local fractal dimension

    Publication Year: 1999, Page(s):231 - 239
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (872 KB)

    In automatic fractal image compression, most of the encoding time is spent on finding the best match between each range block and the domain blocks. We propose the use of the local complexity of the image domain blocks to reduce the number of pairs to be tested on this search. Indexing the contracted domain pools according to their local fractal dimension and using multiple contraction factors we ... View full abstract»

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  • Curvature operators in geometric image processing

    Publication Year: 1999, Page(s):223 - 230
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (216 KB)

    We study the problem of reconstructing an image from a perceptual segmentation based on a geometric classification of its points using non-linear curvature filters. We give a mathematical proof that an image can be reconstructed from the regions of non-zero Gaussian curvatures. This result provides the theoretical background for a new theory of non-linear two dimensional signal processing as propo... View full abstract»

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  • Speckle noise MAP filtering based on local adaptive neighborhood statistics

    Publication Year: 1999, Page(s):347 - 354
    Cited by:  Papers (1)  |  Patents (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (196 KB)

    This work proposes the use of an adaptive neighborhood procedure to extract local statistical properties of images in order to improve a speckle noise “Maximum a Posteriori” (MAP) filtering performance. The strategy consists in growing the local statistically homogeneous area near the pixel in order to estimate its MAP filtering parameters. Measures evaluating both the signal-to-noise ... View full abstract»

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  • Parallelizing MPEG video encoding using multiprocessors

    Publication Year: 1999, Page(s):215 - 222
    Cited by:  Papers (7)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (80 KB)

    Many computer applications are currently using digital video. Recent advances in digital imaging and faster networking infrastructure made this technology very popular, not only for entertainment, but also in health and education applications. However, high quality video requires more storage space and communication bandwidth than traditional data. To deal with this problem, most of the digital vi... View full abstract»

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  • A Monte-Carlo study of classical spectral estimation of the backscatter in k-distributed images

    Publication Year: 1999, Page(s):337 - 346
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (536 KB)

    Some estimators for the spectral density of the return in synthetic aperture radar (SAR) images are studied using Monte Carlo experiences. The spectral density is an important quantifier of the texture that, in turn, can be related to biophysical magnitudes and it can be used to establish the kind of target being observed. These images are contaminated by a particular kind of noise, called speckle... View full abstract»

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  • A framework for attention and object categorization using a stereo head robot

    Publication Year: 1999, Page(s):143 - 152
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (152 KB)

    Describes a framework for dealing with attention and categorization using a robot platform consisting of an articulated stereo head with four degrees of freedom (pan, tilt, left verge and right verge). As a practical result of this development, the system can select a region of interest, perform shifts of attention involving saccadic movements, perform efficient feature extraction and object ident... View full abstract»

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  • Deterministic texture analysis and synthesis using tree structure vector quantization

    Publication Year: 1999, Page(s):207 - 213
    Cited by:  Papers (6)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (480 KB)

    Texture analysis and synthesis is very important for computer graphics, vision, and image processing. This paper describes an algorithm which can produce new textures with a matching visual appearance from a given example image. Our algorithm is based on a model that characterizes textures using a nonlinear deterministic function. During analysis, an example texture is summarized into this functio... View full abstract»

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  • Multiple display viewing architecture for virtual environments over heterogeneous networks

    Publication Year: 1999, Page(s):83 - 92
    Cited by:  Papers (4)  |  Patents (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (88 KB)

    Visualization systems that support multiple-display viewing can greatly enhance user perception. The common approach to provide multiple synchronized views uses a powerful centralized processing unit to support the rendering process on all screens. As an alternative approach, we propose a distributed architecture that supports a flexible and reliable visualization system that, while giving the use... View full abstract»

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  • Quasi 4-8 subdivision surfaces

    Publication Year: 1999, Page(s):17 - 26
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (752 KB)

    This paper presents a new scheme for subdivision surfaces that is based on four-directional meshes. It combines geometry-sensitive refinement with convolution smoothing. The scheme has a simple, efficient implementation and generates well-shaped meshes which converge to smooth surfaces View full abstract»

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  • The 𝒢0A distribution as the true model for SAR images

    Publication Year: 1999, Page(s):327 - 336
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (508 KB)

    For many synthetic aperture radar (SAR) sensors, urban areas, forests and pasture areas have a growing degree of homogeneity, and for each one of these region types there is a distribution class that fits the data best. In this paper, the feasibility of using the 𝒢0 A distribution as a general model is studied, and the practical usefulness of this proposal is shown. The ... View full abstract»

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  • Design of statistically optimal stack filters

    Publication Year: 1999, Page(s):265 - 274
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (276 KB)

    Any gray-scale image can be represented as a “stack” of a decreasing sequence of binary images, obtained by thresholding the gray-scale image at each level. Stack filters are a special class of gray-scale image operators whose filtered images can be represented as the stack of binary images resulting from applying an increasing binary operator for each image of the stack. A classical e... View full abstract»

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  • A methodology for 3D registration of range images for object visualization

    Publication Year: 1999, Page(s):133 - 141
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (216 KB)

    This paper describes an image description method in VRML, using a device for 3D image acquisition. The information obtained from the capture of each object face is organized, and a description of the scanned object is made in the VRML format. This paper presents a study of the minimum number of captures that is necessary to obtain a complete description of the object. The paper shows the problems ... View full abstract»

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  • Segmentation-free printed character recognition by relaxed nearest neighbor learning of windowed operator

    Publication Year: 1999, Page(s):195 - 204
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (844 KB)

    Segmentation is considered by many researchers as the key technology for a reliable optical character recognition (OCR) system. To accomplish sound segmentation, many alternative techniques have been recently proposed. This paper presents a new technique to recognize characters without explicit segmentation. It is based on the automatic construction of a windowed operator by relaxed nearest neighb... View full abstract»

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  • Shape preservation in morphological filtering and segmentation

    Publication Year: 1999, Page(s):247 - 256
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (168 KB)

    The paper discusses the behavior of some image filtering and segmentation approaches, focusing on techniques that belong to mathematical morphology. In particular, the article studies some morphological operators and filters that consider connectivity in a special way and that therefore satisfactorily preserve the significant shapes and contours of an input image. Such morphological connected filt... View full abstract»

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  • Efficient visualization of graphical objects

    Publication Year: 1999, Page(s):73 - 81
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (752 KB)

    The use of appropriate data structures for storing sets of graphical objects can lead to great performance improvements in the visualization of large figures, such as maps and CAD drawings. We present a study on the performance of persistent data structures composed of an R-tree and V-trees, for storing and efficiently retrieving 2D graphical objects. Results are shown to demonstrate the efficienc... View full abstract»

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  • Piecewise trilinear deformation of tomographic models

    Publication Year: 1999, Page(s):113 - 122
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (232 KB)

    Introduces an iterative method that deforms brain models built from tomographic images. The deformation is used for normalization purposes: individual models are deformed to match the shape, orientation and internal morphology of a reference model. In this method, the individual and the reference models are each enclosed in a cube which is subdivided to form a rectangular grid. The vertices in the... View full abstract»

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  • An image processing and belief network approach to face detection

    Publication Year: 1999, Page(s):177 - 186
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (204 KB)

    This paper describes an approach to face detection, which is the first stage of any fully automated human face recognition system. We propose several enhancements to a feature-based approach described by K.C. Yow and R. Cipolla (1997) in an attempt to obtain more accurate results: namely, the attentive feature selection and grouping phases are modified in order to deal with incomplete feature dete... View full abstract»

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  • An optimal algorithm to construct all Voronoi diagrams for k nearest neighbor search in T2

    Publication Year: 1999, Page(s):7 - 15
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (192 KB)

    We generalize to the oriented projective plane T2 an algorithm for constructing all order k Voronoi diagrams in the Euclidean plane. We also show that, for fixed k and for a finite set of sites, an order k Voronoi diagram in T2 has an exact number of regions. Furthermore, we show that the order k Voronoi diagram of a set of n sites in T2 is antipodal to its order n... View full abstract»

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  • Visualizing the unseen body. Architectural potentials of data modeling

    Publication Year: 1999, Page(s):61 - 63
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (132 KB)

    The project is a digital architectural visualization of an individual's physiological data in real time. It is both a probing and representational system that brings together science and art through architectural design. Architecture provides the conceptual and visual tools for expressing the complexities of an individual's physiological state. Visualizing the intricate nature of organic life awak... View full abstract»

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  • Simulation of correlated intensity SAR images

    Publication Year: 1999, Page(s):317 - 326
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (720 KB)

    This paper discusses some methods already available for the simulation of correlated heterogeneous targets in synthetic aperture radar (SAR) images, and extends one of these methods. This new technique is based on the use of a correlation mask and Gaussian random variables, in order to obtain spatially dependent Gamma deviates. Its theoretical properties are presented, along with an algorithm. The... View full abstract»

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