Comment by albertzeyer

That was also my thought. I have used OpenCV 10 years ago for some small things, but today I would simply look for any existing neural network on HuggingFace and maybe train some custom classifier on top if I need sth custom. I cannot really think of any possible case where this would not work better than what you have in OpenCV. And if speed is a concern, there are also many small models, or otherwise you can quantize them yourself, or maybe train yourself a small model with knowledge distillation. You can get this as fast and as small as you want, while still probably outperforming everything that OpenCV can offer.