513,087 research outputs found
VolumeEVM: A new surface/volume integrated model
Volume visualization is a very active research area in the field of scien-tific
visualization. The Extreme Vertices Model (EVM) has proven to be
a complete intermediate model to visualize and manipulate volume data
using a surface rendering approach. However, the ability to integrate the
advantages of surface rendering approach with the superiority in visual exploration
of the volume rendering would actually produce a very complete
visualization and edition system for volume data. Therefore, we decided
to define an enhanced EVM-based model which incorporates the volumetric
information required to achieved a nearly direct volume visualization
technique. Thus, VolumeEVM was designed maintaining the same EVM-based
data structure plus a sorted list of density values corresponding to
the EVM-based VoIs interior voxels. A function which relates interior
voxels of the EVM with the set of densities was mandatory to be defined.
This report presents the definition of this new surface/volume integrated
model based on the well known EVM encoding and propose implementations
of the main software-based direct volume rendering techniques
through the proposed model.Postprint (published version
Interactive Visualization of the Largest Radioastronomy Cubes
3D visualization is an important data analysis and knowledge discovery tool,
however, interactive visualization of large 3D astronomical datasets poses a
challenge for many existing data visualization packages. We present a solution
to interactively visualize larger-than-memory 3D astronomical data cubes by
utilizing a heterogeneous cluster of CPUs and GPUs. The system partitions the
data volume into smaller sub-volumes that are distributed over the rendering
workstations. A GPU-based ray casting volume rendering is performed to generate
images for each sub-volume, which are composited to generate the whole volume
output, and returned to the user. Datasets including the HI Parkes All Sky
Survey (HIPASS - 12 GB) southern sky and the Galactic All Sky Survey (GASS - 26
GB) data cubes were used to demonstrate our framework's performance. The
framework can render the GASS data cube with a maximum render time < 0.3 second
with 1024 x 1024 pixels output resolution using 3 rendering workstations and 8
GPUs. Our framework will scale to visualize larger datasets, even of Terabyte
order, if proper hardware infrastructure is available.Comment: 15 pages, 12 figures, Accepted New Astronomy July 201
Fast parallel volume visualization on cuda technology
In the medical diagnosis and treatment planning, radiologists and surgeons rely
heavily on the slices produced by medical imaging scanners. Unfortunately, most of
these scanners can only produce two dimensional images because the machines that
can produce three dimensional are very expensive. The two dimensional images from
these devices are difficult to interpret because they only show cross-sectional views
of the human structure. Consequently, such circumstances require highly qualified
doctors to use their expertise in the interpretation of the possible location, size or
shape of the abnormalities especially for large datasets of enormous amount of slices.
Previously, the concept of reconstructing two dimensional images to three
dimensional was introduced. However, such reconstruction model requires high
performance computation, may either be time-consuming or costly. Furthermore,
detecting the internal features of human anatomical structure, such as the imaging of
the blood vessels, is still an open topic in the computer-aided diagnosis of disorders
and pathologies. This study proposed, designed and implemented a visualization
framework named SurLens with high performance computing using Compute
Unified Device Architecture (CUDA), augmenting the widely proven ray casting
technique in terms of superior qualities of images but with slow speed. Considering
the rapid development of technology in the medical community, our framework is
implemented on Microsoft .NET environment for easy interoperability with other
emerging revolutionary tools. The Visualization System was evaluated with brain
datasets from the department of Surgery, University of North Carolina, United
States, containing 109 datasets of MRA, T1-FLASH, T2-Weighted, DTI and
T1-MPRAGE. Significantly, at a reasonably cheaper cost, SurLens Visualization
System achieves immediate reconstruction and obvious mappings of the internal
features of the human brain, reliable enough for instantaneously locate possible
blockages in the brain blood vessels without any prior segmentation of the datasets
De-aliasing Undersampled Volume Images for Visualization
We present and illustrate a new technique, Image Correlation Supersampling (ICS), for resampling volume data that are undersampled in one dimension. The resulting data satisfies the sampling theorem, and, therefore, many visualization algorithms that assume the theorem is satisfied can be applied to the data. Without the supersampling the visualization algorithms create artifacts due to aliasing. The assumptions made in developing the algorithm are often satisfied by data that is undersampled temporally. Through this supersampling we can completely characterize phenomena with measurements at a coarser temporal sampling rate than would otherwise be necessary. This can save acquisition time and storage space, permit the study of faster phenomena, and allow their study without introducing aliasing artifacts. The resampling technique relies on a priori knowledge of the measured phenomenon, and applies, in particular, to scalar concentration measurements of fluid flow. Because of the characteristics of fluid flow, an image deformation that takes each slice image to the next can be used to calculate intermediate slice images at arbitrarily fine spacing. We determine the deformation with an automatic, multi-resolution algorithm
Dynamic 3D Network Data Visualization
Monitoring network traffic has always been an arduous and tedious task because of the complexity and sheer volume of network data that is being consistently generated. In addition, network growth and new technologies are rapidly increasing these levels of complexity and volume. An effective technique in understanding and managing a large dataset, such as network traffic, is data visualization. There are several tools that attempt to turn network traffic into visual stimuli. Many of these do so in 2D space and those that are 3D lack the ability to display network patterns effectively. Existing 3D network visualization tools lack user interaction, dynamic generation, and intuitiveness. This project proposes a user-friendly 3D network visualization application that creates both dynamic and interactive visuals. This application was built using the Bablyon.js graphics framework and uses anonymized data collected from a campus network
Visualization of spectral images
Spectral image sensors provide images with a large number of contiguous spectral channels per pixel. Visualization of these huge data sets is not a straightforward issue. There are three principal ways in which spectral data can be presented; as spectra, as image and in feature space. This paper describes several visualization methods and their suitability in the different steps in the research cycle. Combinations of the three presentation methods and dynamic interaction between them, adds significant to the usability. Examples of some software implementations are given. Also the application of volume visualization methods to display spectral images is shown to be valuabl
- …