为了克服传统二值图像边界跟踪速度慢和边界漏跟踪等问题,基于Freeman 链码提出一种通用性强的多起点分段二值图像边界跟踪与边界链码获取算法。在借鉴前人对传统Freeman 链码搜索算法的改进,将平均搜索方向减少为2.5就可以找到新边界点的基础上,进一步将复杂的边界分段处理,令前一边界链的起点作为待跟踪边界链搜索的起点,同时把跟踪后的边界点填充,这样自上而下自左而右的对图像扫描,只需一次即可跟踪完所有的边界,并通过设定阈值消除了单像素冗余点。实验论证结果表明,本文算法能够对复杂网状边界、内部孔洞进行有效地跟踪,同时具有抗噪去除冗余点的能力和较快的速度。

In order to overcome the shortcomings of the traditional binary image boundary tracking, including slow speed and leakage tracking, an algorithm of binary image boundary tracking and boundary chain code acquisition with strong generality is proposed based on the Freeman chain code. Based on the improvement of traditional Freeman chain code search algorithm, the average search direction is reduced to 2.5 when a new boundary point is found. Further the complex boundary segment is processed, and the starting point of the previous boundary chain is used as the starting point for the following boundary chain search, and fills the following boundary points, so that the image scanning from top to down and left to right is only one time to track all the boundaries, and eliminates the single pixel redundancy by setting the thresholds. The experimental results show that the proposed algorithm can effectively track the complex mesh boundary and internal holes, and it has the ability to remove the redundant points with anti-noise and faster speed.