The directional chain code is used to record the contour information data according to the trend of the contour, and this will be very convenient for the smoothing process later on.

采用方向链码记录轮廓信息，它依据轮廓走向的顺序来记录数据，这对以后的光顺处理工作将是十分方便的。

youdao

Material and Method: in this paper, we try to describe and store the image using a data structure, interval list, which was based on the Freeman Chain Code of the image's boundary.

材料和方法：用基于边界点链码的数据结构(线段表)来描述和存储二维图像。

youdao