百度文库资料：
http://wenku.baidu.com/search?word=OTSU+%CB%E3%B7%A8%B4%FA%C2%EB&lm=0&od=0&fr=top_home
百度搜索资料：
https://www.baidu.com/s?wd=otsu%E7%AE%97%E6%B3%95&rsv_spt=1&rsv_iqid=0x8d051eaf00016d1d&issp=1&f=3&rsv_bp=1&rsv_idx=2&ie=utf-8&tn=baiduhome_pg&rsv_enter=1&oq=%E7%BF%BB%E8%AF%91&rsv_t=e6b0YOyh3VC%2FqiWGZFiMzPaBThu3E6hrUXbNHrpyq32PQ0m3GG2UQTQZCfi4V9Xj3dZu&rsv_pq=a8a2daa500017cac&rsv_sug3=7&rsv_sug1=5&rsv_sug7=100&rsv_sug2=1&prefixsug=otsu&rsp=0&inputT=1757208&rsv_sug4=1757676
博客园：
http://www.cnblogs.com/xy-kidult/p/3397553.html
