MIVisionX is probably the library you want for computer vision. As for kernels, you would generally write HIP, which is very similar to CUDA. To my knowledge, there's no equivalent to cupy for writing kernels in Python.
For what it's worth, your post has cemented my decision to submit a few conference talks. I've felt too busy writing code to go out and speak, but I really should make time.
Oh cool! It appears that I've already packaged cupy's required dependencies for AMD GPU support in the Debian 13 'main' and Ubuntu 24.04 'universe' repos. I also extended the enabled architectures to cover all discrete AMD GPUs from Vega onwards (aside from MI300, ironically). It might be nice to get python3-cupy-rocm added to Debian 13 if this is a library that people find useful.
For what it's worth, your post has cemented my decision to submit a few conference talks. I've felt too busy writing code to go out and speak, but I really should make time.