1.灰度 兼容
http://www.526net.com/blog/qianduan/226.html
http://james.padolsey.com/demos/grayscale/grayscale.js
http://my.oschina.net/py115/blog/65196
https://docs.webplatform.org/wiki/css/functions/grayscale
2.透明度 兼容
http://www.generatecss.com/advanced/image-filter-effects/
http://www.cnblogs.com/lostyu/p/3528785.html
http://www.cnblogs.com/fsjohnhuang/p/4127888.html
http://www.cnblogs.com/lostyu/p/3528785.html
http://www.hiheng.com/blog/archives/1088
http://tympanus.net/Tutorials/CSS3FilterFunctionality/index3.html