There really isn't a good one. For heuristics(non ML) based stuff you could try BoofCV which is written in Java, so for Python there is a wrapper https://pypi.

There really isn't a good one. For heuristics(non ML) based stuff you could try BoofCV which is written in Java, so for Python there is a wrapper https://pypi.org/project/PyBoof/ https://pypi.org/project/PyBoof/ http://boofcv.org/index.php?title=Performance:OpenCV:BoofCV http://boofcv.org/index.php?title=Performance:OpenCV:BoofCV