Calculating Z axis of tracked image or 3d tracker algorithm

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Dear, I am working on OpenTLD and CMT trackers, which they are perfect 2D trackers . Do you know good 3D tracker which can return XYZ of the tracked 3d planar image?

If not, any idea on how can I calculate Z if I have the original height and width of on image and the (Height, Width, Scale, XYZ) of the tracked image ?

Note: I want to use it for Augmented Reality application for mobile at the end, and no problem if the library is commercial. Thanks alot