ARFoundation - Tracked image - how to get the camera pose wrt to the tracked image

Hi all,

I managed to create an application based on ARFoundation and Image tracking and it works well.
I could notice that the camera pose is computed/given in the AR session coordinate system (the origin being the position of the camera when the AR session started).
But I'd like to be able to get the camera pose with respect to the tracked image i.e. expressed in a coordinate system based on the image.

For that, I need to get the image position expressed in the AR session coordinate system but I could see it is given only in a self-contained dedicated coordinate system where the position is always (0, 0, 0).

So I'd like to know how to proceed to get the camera pose wrt the tracked image.

Thanks in advance