AN VISUALIZATION MODEL OF GLOBAL IMAGES BASED ON QTM

摘要

Constructing interactive visualization model of global image data is one of the hot research topics in Geo-spatial information sciences. Conventionally, global image data is used as texture in visualization models. Those methods aim to get excellent visualization effect and more attention is paid on improving the speed of image visualization. However, interactive operations, which are the bridge between user and visualization systems, are neglected and this leads to difficulty of spatial analysis in visualization circumstance. To overcome those deficiencies, a new interactive visualization model of global image data based on QTM (Quaternary Triangular Mesh) is presented in this paper. Our approaches star with QTM partition on the spherical surface and visibility culling for improving the speed of image data visualization is described. Then, interactive operations and the implement details of this model are presented. In the end, the experiment is made to test the algorithms and methods approached in this paper by using of Wsiearth. Tif data with 256 gray levels in ArcGIS. The results illustrate that:1) the methods and algorithms approached in this paper are correct and effective; 2) the QTM number and calculating amount for finding QTM in visible frustum are nearly invariable in visualization with the technology of visibility culling.