近期研究一些突破验证码方面的知识,记录下来。一方面算是对这几天学习知识的总结帮助自己理解；另一方面希望对研究这方面的技术同学有所帮助；另外也希望引起网站管理者的注意，在提供验证码时多些考虑进去。由于刚刚接触这方面的知识，理解比较浅显，有错误再所难免，欢迎拍砖。(A recent study of some breakthroughs in validation codes is documented. On the one hand is to study these days summary of knowledge to help you understand; on the other hand, want students to study this aspect of help; also hope to attract the attention of the administrators in the website, provide the verification code more into account. Because just contact this knowledge, understanding is simple, there are errors may exist, please paizhuan.)