Zernike Moments' implementation in OpenCV The reason why Hu moments were implemented in OpenCV and why Zernike moments were not implemented is looking like their performance similar as stated in this paper. 

As stated in the paper Zernike moments' advantage is their reconstruction facility. 

If there is a reliable implementation of Zernike moments compatible with OpenCV I would like to test their shape matching performance with OpenCV's Hu moments shape matching performance and if possible reconstruction facility. 

Thanks.
I haven't used the Zernike module from PeRL's myself, but check out their implementation here.

It's written as an OpenCV module and looks well optimized.

However! I have no idea what their license on this is, so definitely check before you integrate it into anything you're going to distribute or sell.