The digital images are composed of griddling with fixed space between each other , so the simplest chain codes is following the verge and give the direction-value to the linked line of every two adjacent pixels .
数字图像一般是按固定间距的网格采集的，所以最简单的链码是跟踪边界并赋给每2个相邻像素的连线1个方向值。
griddling