VisSym03: Joint Eurographics - IEEE TCVG Symposium on Visualizationhttps://diglib.eg.org:443/handle/10.2312/4022024-03-28T22:46:39Z2024-03-28T22:46:39ZHierarchical Isosurface Segmentation Based on Discrete CurvatureVivodtzev, FabienLinsen, LarsBonneau, Georges-PierreHamann, BerndJoy, Kenneth I.Olshausen, Bruno A.https://diglib.eg.org:443/handle/10.2312/VisSym.VisSym03.249-2582022-03-28T08:35:13Z2003-01-01T00:00:00ZHierarchical Isosurface Segmentation Based on Discrete Curvature
Vivodtzev, Fabien; Linsen, Lars; Bonneau, Georges-Pierre; Hamann, Bernd; Joy, Kenneth I.; Olshausen, Bruno A.
G.-P. Bonneau and S. Hahmann and C. D. Hansen
A high-level approach to describe the characteristics of a surface is to segment it into regions of uniform curvature behavior and construct an abstract representation given by a (topology) graph. We propose a surface segmentation method based on discrete mean and Gaussian curvature estimates. The surfaces are obtained from three-dimensional imaging data sets by isosurface extraction after data presmoothing and postprocessing the isosurfaces by a surface-growing algorithm. We generate a hierarchical multiresolution representation of the isosurface. Segmentation and graph generation algorithms can be performed at various levels of detail. At a coarse level of detail, the algorithm detects the main features of the surface. This low-resolution description is used to determine constraints for the segmentation and graph generation at the higher resolutions. We have applied our methods to MRI data sets of human brains. The hierarchical segmentation framework can be used for brainmapping purposes.
2003-01-01T00:00:00ZHardware-assisted View-dependent Isosurface Extraction using Spherical PartitionGao, JinzhuShen, Han-Weihttps://diglib.eg.org:443/handle/10.2312/VisSym.VisSym03.267-2762022-03-28T08:35:28Z2003-01-01T00:00:00ZHardware-assisted View-dependent Isosurface Extraction using Spherical Partition
Gao, Jinzhu; Shen, Han-Wei
G.-P. Bonneau and S. Hahmann and C. D. Hansen
Extracting only the visible portion of an isosurface can improve both the computation efficiency and the rendering speed. However, the visibility test overhead can be quite high for large scale data sets. In this paper, we present a view-dependent isosurface extraction algorithm utilizing occlusion query hardware to accelerate visible isosurface extraction. A spherical partition scheme is proposed to traverse the data blocks in a layered front-to-back order. Such traversal order helps our algorithm to identify the visible isosurface blocks more quickly with fewer visibility queries. Our algorithm can compute a more complete isosurface in a smaller amount of time, and thus is suitable for time-critical visualization applications.
2003-01-01T00:00:00ZISOSLIDER: A System for Interactive Exploration of IsosurfacesChhugani, JatinVishwanath, SudhirCohen, JonathanKumar, Subodhhttps://diglib.eg.org:443/handle/10.2312/VisSym.VisSym03.259-2662022-03-28T08:35:19Z2003-01-01T00:00:00ZISOSLIDER: A System for Interactive Exploration of Isosurfaces
Chhugani, Jatin; Vishwanath, Sudhir; Cohen, Jonathan; Kumar, Subodh
G.-P. Bonneau and S. Hahmann and C. D. Hansen
We present ISOSLIDER, a system for interactive exploration of isosurfaces of a scalar field. Our algorithm focuses on fast update of isosurfaces for interactive display as a user makes small changes to the isovalue of the desired surface. We exploit the coherence of this update. Larger changes are supported as well. The update to the isosurface is made at a correct level of detail so that not too many operations need be performed nor too many triangles need be rendered. ISOSLIDER does not need to retain the entire volume in the main memory and stores most data out of core. The central idea of the ISOSLIDER algorithm is to determine salient isovalues where surface topology changes and pre-encode these changes so as to facilitate fast updates to the triangulation.
2003-01-01T00:00:00ZSmart Hardware-Accelerated Volume RenderingRoettger1, StefanGuthe, StefanWeiskopf, DanielErtl, ThomasStrasser, Wolfganghttps://diglib.eg.org:443/handle/10.2312/VisSym.VisSym03.231-2382022-03-28T08:35:21Z2003-01-01T00:00:00ZSmart Hardware-Accelerated Volume Rendering
Roettger1, Stefan; Guthe, Stefan; Weiskopf, Daniel; Ertl, Thomas; Strasser, Wolfgang
G.-P. Bonneau and S. Hahmann and C. D. Hansen
For volume rendering of regular grids the display of view-plane aligned slices has proven to yield both good quality and performance. In this paper we demonstrate how to merge the most important extensions of the original 3D slicing approach, namely the pre-integration technique, volumetric clipping, and advanced lighting. Our approach allows the suppression of clipping artifacts and achieves high quality while offering the flexibility to explore volume data sets interactively with arbitrary clip objects. We also outline how to utilize the proposed volumetric clipping approach for the display of segmented data sets. Moreover, we increase the rendering quality by implementing effi cient over-sampling with the pixel shader of consumer graphics accelerators. We give prove that at least 4- times over-sampling is needed to reconstruct the ray integral with sufficient accuracy even with pre-integration. As an alternative to this brute-force over-sampling approach we propose a hardware-accelerated ray caster which is able to perform over-sampling only where needed and which is able to gain additional speed by early ray termination and space leaping.
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