基于链码的肿瘤CT图象层间轮廓线最佳点匹配技术的研究

The Study on Intermediate Contour Matching in CT Tumour Image by Means of Chain Code

本文利用链码理论对已获取的肿瘤层间轮廓线进行编码,将二维轮廓线转化为包含轮廓形状信息的一维链码;采用一种基于链码的匹配技术来完成相邻层轮廓线点匹配,从而建立起其间的对应关系并用于后期的三维重建。本文首先对模式识别中链码的串匹配算法作了一个简要的介绍,并详细分析了应用链码技术获取相邻轮廓间点对应关系的关键难点,使其能够适用于本文的工作。该方法的计算复杂度近似于M*N(M和N分别为相邻轮廓线顶点的数目)。并用实际的肿瘤图象进行实验,结果表明了该方法的有效性。

A method aimed at the formation of optimal matching points between the intermediate contours is reported, which is based on chain code matching technique. Firstly, the two-dimensional contour is coded into one-dimensional string obtaining the shape information of the contour; then the conrespondence between points of two contours is found for further three-dimensional surface reconstruction. After a brief review of string matching technique, some key elements involved in applying string matching technique to find correspendce between points of two contours previous extrated from CT slices are proposed and analyzed. The performance of the method is validated on CT tumor data. The time complexity is proportional to M ＊ N（M and N being the number of vertices of each feature respectively in each slice）.