摘要：This paper firstly describes the techniques of six representative vertex chain codes, they are: original vertex chain code, extended vertex chain code, variable-length vertex chain code, variable-length compressed vertex chain code, dynamic vertex chain code, and equal-length compressed vertex chain code. The description includes the main idea and encoding method of each vertex chain code. Then the chain length, namely the code numbers, the memory occupancy, namely the general binary bits, the code average length of each code, namely bits per code of each vertex chain code were compared respectively by large numbers of experiments. In the end, the evaluation and comparison were given from the view of chain code efficiency. The goal of the paper is to provide convenience and reference for the chain code researchers and users.
