Automatic detection of meaningful isosurfaces is important for producing informative visualizations of volumedata. especially when no information about the data origin and imaging protocol is available. We propose a ...
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ISBN:
(纸本)078037200X
Automatic detection of meaningful isosurfaces is important for producing informative visualizations of volumedata. especially when no information about the data origin and imaging protocol is available. We propose a computationally efficient method for the automated detection of intensity transitions in volumedata. In this approach, the dominant transitions correspond to clear maxima in cumulative Laplacian-weighted gray value histograms. Only one pass through the datavolume is required to compute the histogram. Several other features which may be useful for exploration of data of unknown origin can be efficiently computed in a similar manner, e., enclosed volume, isosurface area, mean gradient. The detected intensity transitions can be used for setting of visualization parameters for surface rendering. as well as for direct volume rendering of 3-D datasets. When using surface rendering, the detected dominant intensity transition values correspond to the optimal surface isovalues for extraction of boundaries of the objects of interest. In direct volume rendering, such transitions are important for generation of the transfer functions, which are used to assign visualization properties to data voxels and determine the appearance of the rendered image. The proposed method is illustrated by examples with synthetic data as well as real biomedical datasets.
A system to represent and visualize scalar volumedata at multiple resolution is presented. The system is built on a multiresolution model based on tetrahedral meshes with scattered vortices that can be obtained from ...
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A system to represent and visualize scalar volumedata at multiple resolution is presented. The system is built on a multiresolution model based on tetrahedral meshes with scattered vortices that can be obtained from any initial dataset. The model is built off-line through data simplification techniques, and stored in a compact data structure that supports fast on-line access. The system supports interactive visualization of a representation at an arbitrary level of resolution through isosurface and projective methods. The user can interactively adapt the quality of visualization to requirements ct a specific application task and to the performance of a specific hardware platform. Representations at different resolutions can be used together to further enhance interaction and performance through progressive and multiresolution rendering.
A holographic visualization of volumedata based on adjustable ray to optical-wave conversion is *** holograms are generated by emitting multiple rays to sample the volumetric *** interval sampling,object light wave a...
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A holographic visualization of volumedata based on adjustable ray to optical-wave conversion is *** holograms are generated by emitting multiple rays to sample the volumetric *** interval sampling,object light wave adjustment,and information composition are sequentially performed during the march of *** program is accelerated in parallel to reduce the total time,and the reconstructions are dynamically adjusted to express different parts of an *** experiments verify that the proposed method can holographically reconstruct the surface and interior information of objects.
In this paper, we address the problem of the efficient visualization of large irregular volumedata sets by exploiting a multiresolution model based on tetrahedral meshes. Multiresolution models, also called Level-Of-...
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In this paper, we address the problem of the efficient visualization of large irregular volumedata sets by exploiting a multiresolution model based on tetrahedral meshes. Multiresolution models, also called Level-Of-Detail (LOD) models, allow encoding the whole data set at a virtually continuous range of different resolutions. We have identified a set of queries for extracting meshes at variable resolution from a multiresolution model, based on field values, domain location, or opacity of the transfer function. Such queries allow trading off between resolution and speed in visualization. We define a new compact data structure for encoding a multiresolution tetrahedral mesh built through edge collapses to support selective refinement efficiently and show that such a structure has a storage cost from 3 to 5.5 times lower than standard data structures used for tetrahedral meshes. The data structures and variable resolution queries have been implemented together with state-of-the art visualization techniques in a system for the interactive visualization of three-dimensional scalar fields defined on tetrahedral meshes. Experimental results show that selective refinement queries can support interactive visualization of large data sets.
In this paper, we extend our generic ldquoGeoAnalyticsrdquo visualization (GAV) component toolkit, based on the principles behind Visual Analytics (VA), to also support time-oriented, geographically referenced and mul...
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ISBN:
(纸本)9781424423798
In this paper, we extend our generic ldquoGeoAnalyticsrdquo visualization (GAV) component toolkit, based on the principles behind Visual Analytics (VA), to also support time-oriented, geographically referenced and multivariate attribute volumetric data. GAV includes components that support a mixture of technologies from the three datavisualization fields: information visualization (InfoVis), geovisualization (GeoVis) and scientific visualization (SciVis). Our research concentrates on visual user interface (VUI) techniques through dynamic and direct data manipulation that permit the visual analytical process to become more interactive and focused. This paper encourages synergies between well-known information- and volume data visualization methods applied in a multiple-linked and coordinated views interface. We address challenges for improved data interaction techniques with volumetric data and the need for immediate response. Varieties of explorative data analysis (EDA) tasks and the possibility to view the information simultaneously from different perspectives and scenarios are discussed. The effectiveness of our geovisual analytics framework is demonstrated in a tailor-made volumedata explorer (VDE) application that integrates InfoVis, GeoVis and SciVis visualization methods assembled from GAV components. VDE facilitates dynamic exploration and correlation of temporal ocean space temperature and salinity data supplied in a NetCDF format from NOAA. This real-world phenomenon that corresponds to a huge volumetric data set comprises more than 31 million values for a time period of 12 months in 1994.
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