Error: CV_LOAD_IMAGE_GRAYSCALE not declared when compiling Aloam

[ruziniuuuuu]

I encountered the following error when running the catkin_make command as described in Section 3.1 while trying to build the A-LOAM package in ROS Noetic with OpenCV (higher version):

The key issue seems to be that CV_LOAD_IMAGE_GRAYSCALE is not declared when trying to read an image in kittiHelper.cpp.

I was able to resolve this by changing CV_LOAD_IMAGE_GRAYSCALE to cv::IMREAD_GRAYSCALE as shown here:

After making that change, I was able to successfully compile the package.