Accession Number : ADA193649

Title :   Rendering of Surfaces from Volume Data,

Corporate Author : NORTH CAROLINA UNIV AT CHAPEL HILL DEPT OF COMPUTER SCIENCE

Personal Author(s) : Levoy, Marc

PDF Url : ADA193649

Report Date : Feb 1988

Pagination or Media Count : 15

Abstract : The application of volume rendering techniques to the display of surfaces from sampled scalar functions of three spatial dimensions is explored. Fitting of geometric primitives to the sampled data is not required. Images are formed by directly shading each sample and projecting it onto the picture plane. Surface shading calculations are performed at every voxel with local gradient vectors serving as surface normals. In a separate step, surface classification operators are applied to obtain a partial opacity for every voxel. Operators that detect isovalue contour surfaces and region boundary surfaces are presented. Independence of shading and classification calculations insures and undistorted visualization of 3-D shape. Non-binary classification operators insure that small or poorly defined features are not lost. The resulting colors and opacities are composited from back to front along viewing rays to form an image. The technique is simple and fast, yet displays surfaces exhibiting smooth silhouettes and few other aliasing artifacts. The use of selective blurring and super-sampling to further improve image quality is also described. Examples from two applications are given: molecular graphics and medical imaging.

Descriptors :   *IMAGE PROCESSING, *COMPUTER GRAPHICS, *MEDICAL COMPUTER APPLICATIONS, BOUNDARIES, CLASSIFICATION, COLORS, DISPLAY SYSTEMS, GRAPHICS, IMAGES, MOLECULES, OPACITY, PICTURES, QUALITY, RADIOGRAPHY, REGIONS, SAMPLING, SCALAR FUNCTIONS, SHADOWS, SILHOUETTES, SPATIAL DISTRIBUTION, SURFACES, VIEWERS, VOLUME, X RAYS, THREE DIMENSIONAL, TOMOGRAPHY, ELECTRON DENSITY, MAPS

Subject Categories : Computer Systems
      Medicine and Medical Research

Distribution Statement : APPROVED FOR PUBLIC RELEASE