Failed to run ORB-SLAM2 ROS RGBD

[Shengshu-Liu]

As the figure shown above, after resolving #1, I ran into another problem which might be using the wrong version of OpenCV.

[Shengshu-Liu]

According to https://github.com/Shengshu-Liu/ORB_SLAM2_sparse_map_saving/blob/master/README.md, the author said the project was tested with OpenCV 2.4.11 and OpenCV 3.2, therefore:

Actions:

Changed the version of OpenCV from 2.4.13 to 3.2.0.
Changed
find_package(OpenCV 2.4.13 EXACT)
to
find_package(OpenCV 3.2.0 EXACT)

Outcomes:

Compilation failed, outputted the same results as #1 (comment)

[Shengshu-Liu]

Actions:

Reverted action #8 (comment), changed
find_package(OpenCV 3.2.0 EXACT)
to
find_package(OpenCV 2.4.13 EXACT)

[Shengshu-Liu]

Actions:

After reading https://blog.csdn.net/CH_monsy/article/details/124671155, in D435i.yaml, I changed
Viewer.PointSize:2

to
Viewer.PointSize: 2

Outcomes:

Failed, gave the same output as #8 (comment)

[Shengshu-Liu]

Actions:

Reverted action #8 (comment)

[Shengshu-Liu]

Actions:

1. Commented
   #include <unistd.h>
   in the top include folder
2. In .bashrc, changed

export PATH=/usr/local/cuda-11.5/bin:/opt/ros/melodic/bin:/home/zimo/.local/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin

to

export PATH=/opt/ros/melodic/bin:/home/zimo/.local/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin

Outcomes:

Failed, gave the same output as #8 (comment)

[Shengshu-Liu]

Conclusions:

After loads of debugging, used the same version of OpenCV in all three CMakeLists.txt located in
path_to_ORB-SLAM2/CMakeLists.txt
path_to_ORB-SLAM2/Examples/ROS/ORB_SLAM2/CMakeLists.txt
path_to_ORB-SLAM2/Thirdparty/DBoW2/CMakeLists.txt
and tried three different versions of OpenCV.
I found out that:

1. All three projects (original, dense map saving, sparse map saving) could be compiled successfully with OpenCV-2.4.13, but gave Failed to run ORB-SLAM2 ROS RGBD #8 (comment) at runtime. According to some tutorials online, the reasons were the incompatibility between Eigen-3.1.0 and OpenCV-2.4.13, and using Eigen-3.2.0 can solve the problem, but I never tried it.
2. When complied with the newly installed OpenCV-3.4.0 (with full path given explicitly)
   find_package(OpenCV 3.4.0 EXACT PATHS "/home/zimo/Work/opencv-3.4.0")
   all three projects worked fine.
3. When compiled with OpenCV-3.2.0, all three projects gave the same results as Failed to run ORB-SLAM2 ROS RGBD #8 (comment). Even after I installed another OpenCV-3.2.0 in home directory and gave the full path in find_package,
   find_package(OpenCV 3.2.0 EXACT PATHS "/home/zimo/Work/opencv-3.2.0")
   the system still detected the old one whose libs are in /usr/lib/x86_64-linux-gnu and just ignored the new one, which is kind of bizzare.
4. OpenCV-2.4.13 was installed in

/usr/local/lib
/usr/local/include/opencv
/usr/local/include/opencv2
/usr/local/share/OpenCV

The old OpenCV-3.2.0 was installed in

/usr/lib/x86_64-linux-gnu
/usr/include/opencv
/usr/include/opencv2
/usr/share/OpenCV

Another OpenCV-3.2.0 was installed in a designated folder.
OpenCV-3.4.0 was installed in a designated folder.
(1) Compilation with OpenCV-2.4.13 succeeded but runtime error occured #8 (comment)
(2) Compilation with the old OpenCV-3.2.0 failed and gave error #1 (comment)
(3) Compilation with the new OpenCV-3.2.0 still failed since the system still detected the old OpenCV-3.2.0
(4) Everything worked fine with OpenCV-3.4.0

[Shengshu-Liu]

I want to see if OpenCV-2.4.11 works so I tried to install OpenCV-2.4.11 but an error occurred Shengshu-Liu/opencv#2 (comment)
And I gave up on more attempts with different version of OpenCV and sticked with OpenCV-3.4.0.