During some experiments, I found that some components require OpenCV. As this is currently not integrated within the CI I created #5519. During further local research I found the usage of HAVE_OPENCV within 26 source files - but the constant is never defined in pcl_config.h.in. Adding #cmakedefine HAVE_OPENCV 1 didn't help either. All HAVE_ defines seems to be defined by calling PCL_ADD_GRABBER_DEPENDENCY, but there is nothing for OpenCV.

I didn't found out if OpenCV support should be removed or not, so the integration should be fixed or removed (at best before release of 1.13.0)