基于多尺度等值面设计传递函数  

Transfer Function Based on Multi-scale Iso-Surface

作　　者：周芳芳[1] 樊晓平[1] 叶榛[2] 

机构地区：[1]中南大学信息科学与工程学院自动化工程研究中心,湖南长沙410075 [2]清华大学智能技术与系统国家重点实验室,北京100084

出　　处：《小型微型计算机系统》2007年第1期144-147,共4页Journal of Chinese Computer Systems

基　　金：国家自然科学基金项目(69975003)资助.

摘　　要：在体绘制中传递函数将体数据转换成光学参数,因此体绘制的效果直接由传递函数决定.本文提出了基于多尺度等值面设计传递函数的高效方法.该方法通过梯度阈值提取边界体元来简化数据场,然后将提取等值面的目标函数的计算化简为累加的拉普拉斯加权的直方图极值的计算.最后对直方图进行多尺度平滑,利用提取出的多尺度等值面来设计高斯型传递函数,提高了等值面的准确度和传递函数的设计效率.Direct volume rendering of scalar fields uses a transfer function to map the measured data to the colors and opacities. This paper advocates the use of multi-scale boundary information in transfer functions with a methodology for computing highquality boundary measurements. A new multi-scale approach for the extraction of boundary from volume datasets is described. First, the boundary voxels are defined with gradient magnitude threshold to refine the dataset. Then the boundaries are detected as the maxima in cumulative Laplacian-weighted gray value histograms with a computationally efficient method roquiring only a single pass through the boundary volume. Multi-scale smoothing of the cumulative Laplacian-weighted gray value histogram using Gaussian filters of various sizes allows the iso-surfaces to be defined hierarchically over a scale space map. Finally the Gaussian transfer function is designed by the boundaries for the high-quality rendering.

关 键 词：体绘制 传递函数 多尺度 等值面 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]