It depends on how in-depth you are planning to go. A number of languages are already have extensions and libraries just for this sort of task.
I’m more than a little biased towards Python so hopefully someone else has a good suggestion to balance things out if nothing else. For getting started unless you have an end goal in mind or someone from your field suggests using something different you could probably just stick to Python. It’s certainly a quick language to get started with (realtively speaking) and has libraries for a whole host of things. I’ve used some degree of image processing, pattern recognition and more general anlysis with Python (scienftic research) and found it realtively straightforward.
If you don’t get a clear cut response here try just searching around on the web. There will inevitably be a few folks who’ve shared their experiences in that field. There may well be more than one good answer and you’ll have to make up your own mind but learning to prgoram in any language will make it signficantly easier to pick up another one in the future should you find it necessary. I’d say most folks use a couple of languages at least even if they have a favourite.