一种基于距离的PM滤波等值面CT数据折射体绘制方法

折射效果可以增强体绘制图像的真实感,但是数据集中的噪声严重影响了绘制质量。在本文中,我们提出了一种基于等值面的折射体绘制方法。首先提取出要绘制的等值面,计算数据集中各点到等值面的最小距离,生成一个水平面集。然后用偏微分的方法对这个新的数据集进行滤波。最后用改进的光线投射算法进行折射绘制:在原数据集中进行颜色和不透明度的累积,但在新数据集的折射面位置,光线前进方向按Shell定理发生改变。结果显示绘制质量得到了显著的提高。

Refractive Volume Rendering of CT Data Iso-surfaces with a Distance PM Filter

Refractive effects in volume rendering can enhance the realism of volume graphics,but the quality of resultant images is highly sensitive to noises of the dataset.In this paper,we present a refractive volume rendering method for iso-surfaces.Firstly,a level set based on the minimal distance from each sample point to the iso-surface is generated.Then the level set is smoothed by PDE equation.At last,regular ray casting is performed at iso-surfaces.The color and opacity is accumulated in the original dataset,but the ray direction is changed according to Snell＇s law at the refractive surface in the level set.Experiments show that the quality of resultant images is enhanced.