[转] Histogram of oriented gradients (HOG)

http://blog.163.com/lizhh@126/blog/static/210660602009528111110998/

http://314945387.qzone.qq.com/blog/1235139213

http://www.cnblogs.com/platero/archive/2010/10/19/1870149.html

http://apps.hi.baidu.com/share/detail/24943634