I mainly look at 3 things:

I mainly look at 3 things:

As Przemysław Dolata mentionned, it's not as much a question of language as it is a question of using libraries giving you all the robust and efficient basic building blocks to develop.

IMO, OpenCV is probably your best choice as it is very efficient (many functions are GPU accelerated if build with appropriate support), has a huge user community, commercial and academic, and many bindings to other languages like Python.

If you are building a complete system, as opposed to "simply" developing a new algorithm for publication, you will need to pay careful attention to the integration with hardware (camera, lidar, etc.) and the deployment environment that your system will run onto.

Ex: You are better think ahead if you intend to run on a low memory Linux distribution to guide a UAV by computer vision, SLAM, etc.

Support and Documentation

Quite a simple heuristic : let's S be the langage, if S is Python then pick S, otherwise look again. :)