非等分辨率光线跟踪体绘制方法及其在超声CT三维成像中的应用

光线跟踪绘制是获得广泛应用的三维标量场数据的计算机可视化方法之一,它所处理的数据量之大要求数据压缩存放.本文推导了非等分辨率条件下数据压缩存贮时直角坐标系中的广义的射线方程及链式关系,研究了它在基于CT切片的超声三维成像中的应用.实例表明,该方法能够真实反映原始数据特征,即,对于大尺度物体(相对于换能器声场分辨率),该方法能够得到清晰的图像,而对于小尺度物体,由于原数据分辨率不够导致图像模糊,但是该方法仍然能够定性表明缺陷的存在.

Non-isotropic resolution ray tracing for volume rendering alogrithm and its application in 3D ultrasonic imaging based on CT

Ray tracing for volume rendering (RTVR) is one of the most efficient ways to visualize 3D scalar data,and has been widely used.The large amount of data needs an economical storage scheme.In this paper,we deduce the ray-tracing equation and chain-relations of non-isotropic resolution data field under Cartesiane-coordinate system.We also study its application in 3-dimensional ultrasonic imaging based on series CT slices data from NDT.Examples show that the method used by us can reflect the original data really and be used to classify different kinds of materials.The resulted image is quite good with BIG objects,though blur with SMALL ones due to the lower resolution of the original data.