http://www.webhek.com/post/optimize-gifs.html
https://graphicdesign.stackexchange.com/questions/20908/how-to-remove-every-second-frame-from-an-animated-gif/20937#20937
http://www.cnblogs.com/fullhouse/archive/2012/02/20/2360545.html
http://www.webhek.com/post/optimize-gifs.html
https://graphicdesign.stackexchange.com/questions/20908/how-to-remove-every-second-frame-from-an-animated-gif/20937#20937
http://www.cnblogs.com/fullhouse/archive/2012/02/20/2360545.html