Not sure if you're looking for CV or DL libraries. If you're looking for DL libraries, you can't go wrong with Tensorflow or PyTorch for research/development, and Tensorflow or Caffe2 for deployment. Tensorflow's a bit difficult to learn, but has a lot of great tooling around it, and PyTorch is the opposite. The other frameworks are fine, but don't have the same amount of documentation & beginner resources.