Hi there!
First of all I read your "PinkIMPapp data flow" presentation, and I have some comments about it! Anyway, that's really a pretty cool and interesting project for me, I have done a variety of CUDA-oriented developing (in Freelancer.com and off-site)
Briefly, I could say that considering that "80% of the image processing libraries are called from opencv" the OpenCV-CUDA lib will probably be of hand for most of the conversion process. Also the case is that "PinkLib is a wrapper written in C++ CLI" then this is comfortable because CUDA is not really easy to call from C# code, it could be much tricky.
I am open to discussion and would be glad to do so.
best regards,
Thanassis