小波变换技术在曲面重构中的应用

Application of Wavelet Transform Technology to Surface Reconstruction

逆向工程的核心技术是自由曲面重构。传统的逆向工程曲面重构方法是直接重构,即不对控制顶点进行压缩,直接利用重构数据。因此数据处理能力较弱,重构过程中数据的存储量和计算量非常大。对此提出利用小波变换技术减少准均匀三次B样条曲面控制顶点个数的方法,使得逆向工程中重构曲面的控制顶点个数大大减少,并且使压缩后的曲面与原曲面的形状大致相同。实验结果表明本文方法实现了曲面的分级压缩,简化了数据处理,降低了重构过程代价,符合工程实际需求。

The core technology of reverse engineering is free surfaces reconstruction. Traditionally, surface reconstruction is built directly by using reconstruction data, which control vertexes aren＇t compressed. So it has a relatively weak data processing ability,and the storage and calculation of data in the reconstruction process is tremendous. A method applying wavelet transform technology, which can reduce the amount of controlling vertexes of cubic quasi-uniform B-spline surfaces, was presented. The amount of control vertexes to reconstruct curved surfaces decreases greatly. The curved surface with its data compressed approximates the original surface shape. Experiment results show that the method implements surfaces＂ hierarchical compressing, simplifies data processing and reduces the cost of reconstruction and accords with engineering demand.