编译orb slam遇到的一些bug和错误解决方案

1. error usleep not in this scope
   解决方案：在你报错的那些文件里面加上#include<unistd>

/usr/lib/x86_64-linux-gnu/libopencv_highgui.so.2.4.9: undefined reference to `TIFFSetWarningHandler@LIBTIFF_4.0'
//usr/lib/x86_64-linux-gnu/libSM.so.6: undefined reference to `uuid_unparse_lower@UUID_1.0'
/usr/lib/x86_64-linux-gnu/libopencv_highgui.so.2.4.9: undefined reference to `TIFFSetErrorHandler@LIBTIFF_4.0'

collect2: error: ld returned 1 exit status
CMakeFiles/Makefile2:141: recipe for target ‘CMakeFiles/mono_tum.dir/all’ failed
make[1]: *** [CMakeFiles/mono_tum.dir/all] Error 2
CMakeFiles/rgbd_tum.dir/build.make:162: recipe for target ‘…/Examples/RGB-D/rgbd_tum’ failed
make[2]: *** […/Examples/RGB-D/rgbd_tum] Error 1
CMakeFiles/Makefile2:215: recipe for target ‘CMakeFiles/rgbd_tum.dir/all’ failed
make[1]: *** [CMakeFiles/rgbd_tum.dir/all] Error 2
Makefile:83: recipe for target ‘all’ failed
make: *** [all] Error 2

解决方案：
在CmakeLists里面将find_page(opencv 版本号改成自己的）。怎么看版本？```pkg-config --modversion opencv```