A New Contour Tracing Algorithm in Eight-Connected Binary Images

A new contour tracing algorithm in eight-connected binary images is presented in this paper. The algorithm adopts a unique contour labeling method using automaton. Connectivity information is preserved and inner and outer contours can be distinguished. Furthermore, it only labels west side of the outer contour and east side of the inner contour while traversing the image simultaneously. And it is also capable of generating all three types of chain code after tracing the contours. It is demonstrated that it increases the coding efficiency for binary image effectively and outperforms the algorithms which compute chain code from run-length code.