Canny's Gaussian kernel...

edit

So I've been experimenting with different Gaussian kernels within the Canny Edge detector. One thing that's jumped out at me, is I can't seem to reproduce the kernel that's listed here:

https://docs.opencv.org/2.4/doc/tutor...

nor here:

https://en.wikipedia.org/wiki/Canny_e...

My question: how did this particular kernel matrix have these particular values, and lines up with the generic formula?

Cause when I plug in a few indexes, the results don't match.

Thanks for your advice, Charles.