A Frequency-Sensitive Point Hierarchy for Images and Volumes

This paper introduces a method for converting an image or volume sampled on a regular grid into a space-efficient irregular point hierarchy. The conversion process retains the original frequency characteristics of the dataset by matching the spatial distribution of sample points with the required frequency. To achieve good blending, the spherical points commonly used in volume rendering are generalized to ellipsoidal point primitives. A family of multiresolution, oriented Gabor wavelets provide the frequency-space analysis of the dataset. The outcome of this frequency analysis is the reduced set of points, in which the sampling rate is decreased in originally oversampled areas. During rendering, the traversal of the hierarchy can be controlled by any suitable error metric or quality criteria. The local level of refinement is also sensitive to the transfer function. Areas with density ranges mapped to high transfer function variability are rendered at higher point resolution than other...

• Type: Conference
• Year: 2003
• Where: VISUALIZATION
• Authors: Tomihisa Welsh, Klaus Mueller
• Keywords: Irregular Point Hierarchy, Point Hierarchy, Transfer Function, Visualization, VISUALIZATION 2003