error,这是什么原因

[superyeevi]

/home/u18/rgbdslam_cg-master/app/visual_odometry.cpp:43:4: error: ‘cg’ has not been declared
cg::TUMDataRGBD tum_data_rgbd("/home/u18/rgbdslam_cg-master/rgbd_dataset_freiburg2_desk/", 1);
^~
/home/u18/rgbdslam_cg-master/app/visual_odometry.cpp:46:9: error: ‘tum_data_rgbd’ was not declared in this scope
tum_data_rgbd.getK(K);
^~~~~~~~~~~~~
/home/u18/rgbdslam_cg-master/app/visual_odometry.cpp:74:14: error: ‘tum_data_rgbd’ was not declared in this scope
if (!tum_data_rgbd.get_rgb_depth(img_color, img_depth)) {
^~~~~~~~~~~~~
CMakeFiles/visual_odometry.dir/build.make:75: recipe for target 'CMakeFiles/visual_odometry.dir/app/visual_odometry.cpp.o' failed
make[2]: *** [CMakeFiles/visual_odometry.dir/app/visual_odometry.cpp.o] Error 1
CMakeFiles/Makefile2:185: recipe for target 'CMakeFiles/visual_odometry.dir/all' failed
make[1]: *** [CMakeFiles/visual_odometry.dir/all] Error 2
Makefile:90: recipe for target 'all' failed
make: *** [all] Error 2