PhotoShop alternative tools

http://www.photocap.com.tw/Tuition/tuition.htm

http://www.cnblogs.com/plwang1990/archive/2013/05/02/3054305.html

http://dasu88.twbbs.org/?p=62

http://blog.sina.com.cn/s/blog_598a398c0100afj9.html

http://louishan.com/articles/5-free-photoshop-alternative-softwares.html