Hough Forest链接老出错，尽管已经把OpenCV的库安装好了，依然出现undefined reference问题。根据经验做了如下试验：由于我在编译opencv的时候将 prefix设置自定义的安装目录，因此在编译hough forest之前我首先将我opencv的安装目录添加到/etc/ld.so.conf目录下，然后ldconfig一下，发现依然不行，最终在网上找打了一个合适的办法成功编译。
I have been working on running CRFOREST in Ubuntu machine for 7 months. Here are some suggestions:
for Makefile:
CRForest-Detector: $(OBJS)
$(CC) $(LIBDIRS) -o $@ $+$(OPT) $(LIBS)
NOTE: Please put $(LIBS) at the end, otherwise, I would suggest you re-install the package opencv in Ubuntu following a proper configuration guide.将makefile里面的LIBS环境变量放到最后即可。