Generation of Multi-Resolution Geometric Models and Progressive Graphic Display of 2D/3D Objects Using Chain Code Representations
| Autor: | I-Pin Chen, 陳一斌 |
|---|---|
| Rok vydání: | 2001 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 89 In computer applications such as computer—aided part manufacturing, object collision detection, object classification, and object browsing on the network, the geometric shape of objects must be mathematically represented and graphically rendered. In this dissertation we deal with the generation of multi-resolution geometric models and progressive graphic display of 2D/3D objects using chain code representation. We are concerned with object browsing and matching with a capability of multi-resolution representation of the object on computers, especially in a network environment. The consideration factors of the research are mainly the processing time including the network data transmission and the graphic display, the availability of different levels of detail for display, and the last and less important factor of memory storage size. In the first part of this dissertation, we present a recursive representation and progressive display of binary objects for efficient network browsing. We describe the representation and display of a convex and/or a concave polygonal object. Also, the object model modification under rotation, scaling, and translation variations is described. Our method is generally better than many existing methods in terms of data transmission rate, progressive display capability, and view modification under R/S/T variations. Simulation results are provided to illustrate the performance of our method. In the second part, we present a simple recursive method for converting a chain code into a quadtree with a lookup table. The table lookup method for generating the quadtree black nodes and the new chain code elements is designed to speed up the conversion process. The result indicates that our method is conceptually simpler and runs faster. In the third part, a recursive method for converting a set of chain codes into an octree is proposed. We describe the generation of the flags when tracing the chain codes, and the flag propagation for the generation of octree black nodes. Our conversion method runs faster than other method in terms of the total execution time of major operations, as indicated by the lemmas. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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