随着数据采集尤其是3维激光扫描技术的发展,对地物目标建立的表面模型越来越精细,由于其不仅导致数据存储量急剧增大,也降低了图形实时交互显示的速度,因此必须对表面模型数据进行压缩处理。为了对原始扫描构模表面模型进行合理、有效的压缩处理,在Garland提出的表面模型压缩算法的基础上,提出了一种新的基于边收缩的表面模型数据压缩算法。该算法首先依据二次误差度量准则计算边收缩的代价,同时确定各边收缩的顺序,然后利用半空间测试方法判断边收缩的合法性,以实现表面模型的边界区域与内部区域的同步压缩。实践表明,该算法不仅在高压缩比的情况下仍能保留原始模型的几何特征,而且能有效地保证压缩模型的质量。

With the rapid development of data acquisition techniques,especially 3D laser scanning,surface models of any object constructed by modeling approaches become more and more elaborated,which result in great amount of data to be stored,and decreasing the speed of processing models.It is necessary to reasonably and effectively compress or simplify the surface model constructed from the original scanned point clouds.Based on the data compression algorithm proposed by Garland,a new algorithm for 3D surface model compression with edge contraction is put forward in this paper.The algorithm uses the rule of quadric error to calculate contraction cost of each edge and control the sequence of edges to be contracted.Half space testing is introduced to judge the validity of edge contraction.With this new algorithm,both the triangular faces at the boundary and in the interior of the surface model are compressed synchronously.Experimental results show that the algorithm can preserve the geometric characteristics of the original surface model at high compression ratio,which effectively guarantees the quality of the compressed surface models.