参考:
【1】Hough transform http://rosettacode.org/wiki/Hough_transform#MATLAB (里面有各种语言实现的hough变换)
【2】Matlab 霍夫变换 ( Hough Transform) 直线检测 http://www.cnblogs.com/Ponys/p/3146753.html
【3】Matlab实现——霍夫变换直线检测 http://blog.youkuaiyun.com/abcjennifer/article/details/6673799