Query on the toolbox polynomial output

[Nagarajan Balamukundan]

Hello,

Thanks for a very handy toolbox and a comprehensive readme page. I have a small query when I refer to both the google site (link) and the corresponding paper (link) that I believe is the basis of this toolbox.

The polynomial coefficient a1 is assumed to be 0 as per the paper with supporting argument on the derivative for the function f() being 0 at rho = 0. However, I see non zero coefficient a1 value for the fisheye cameras that I'm trying to calibrate. Also, the readme does not talk about omitting coefficient a1 from the list of calibration parameters since its value can be assumed to be 0.

Could someone in this group kindly help clarify this?

Many thanks,

Nagarajan