基于物质分类的频域体绘制算法

FREQUENCY DOMAIN VOLUME RENDERING BASED ON CLASSIFICATION

本文提出了一种新的频域体绘制算法．与以前的频域体绘制（ＦＶＲ—ＦｒｅｑｕｅｎｃｙｄｏｍａｉｎＶｏｌｕｍｅＲｅｎｄｅｒｉｎｓ）算法不同的是，该算法借鉴并引入了传统空域绘制算法中普遍采用的分类过程，从而使得生成的图象更加接近于空域方法的结果．在此算法的基础上，文中又提出了一种在图象效果上类似于传统空域面绘制（ＳｕｒｆａｃｅＲｅｎｄｅｒｉｎｇ）算法的方法．该方法通过在频域重采样过程中运用Ｌａｐｌａｃｅ算子，使得数据场的三维物质边界面得到突出．为了减少传统的二维、三维快速傅里叶变换（ＦＦＴ）的空间代价，引入了多维快速哈特利变换（ＦＨＴ）．最后在时间效果上与空域方法做了对比，并给出了几个生成图象的实例，对应地与空域绘制算法的结果进行了比较．

A new improved frequency domain volume rendering algorithm is presented in this paper. In this algorithm, the classification of function values is intro duced into the fundamental frequency domain volume rendering. Besides, takingadvantage of the Laplace's operator, a method for sharpening the 3D boundaries be tween any two different substances is designed. In order to reduce both time andspace cost, the 3D Fast Hartley Transform (FHT) is implemented. Some imagesproduced by this algorithm are given.