[OS X, CoreImage] How to bind a CIImage to an openCL image2d?


I guess a lot of you are coding on a Mac, so I’ve got a simple question for you.

I’ve got a CIImage (CoreImage framework) which is already on the GPU memory. So far, I transfer the CIImage into a NSBitmapImageRep on the CPU memory before resending back to the GPU memory in an OpenCL image2d.
Yes, it sounds stupid but I don’t know how to do otherwise :)
How to create (or bind) an OpenCL image2d directly from a CIImage?

I know that a CIImage can be transformed into an openGL texture, an openGL texture can be bound with a IOSurface and then an IOSurface can be bound to an openCL image2d.
Has anyone already tried to do something like that or have a pointer to some sample code?

Thanks for your help!