Build Failure on ROS Noetic (OpenCV 4): Incorrect include path for opencv/cv.h

[aaronjs99]

Hi,

I encountered a build failure when trying to compile SC-LIO-SAM on ROS Noetic (Ubuntu 20.04), which uses OpenCV 4.

Error:
The build fails with the error: fatal error: opencv/cv.h: No such file or directory in include/utility.h (and potentially other files).

Cause:
This seems to be because the code uses the old OpenCV 2/3 include path #include <opencv/cv.h>, which is not standard in OpenCV 4 installations provided with ROS Noetic.

Solution:
I was able to fix the build by changing the include statement in include/utility.h (line 15) from:
#include <opencv/cv.h>
to:
#include <opencv2/opencv.hpp>

Suggestion:
Could you please consider updating the include paths to be compatible with OpenCV 4 for ROS Noetic users?

Thanks for the great package!