http://www.cnblogs.com/tornadomeet/archive/2012/08/17/2644903.html

http://www.cnblogs.com/slysky/archive/2011/10/30/2229530.html

http://blog.csdn.net/yangtrees/article/details/7482960

http://blog.sina.com.cn/s/blog_7e1ecaf30100wgfw.html

http://blog.csdn.net/jwh_bupt/article/details/7628665

图像检测之sift and surf---sift中的DOG图 surf hessian