Fisheye Model in Pix4D

Hi, I am tring to understand Pix4D’s Fisheye distortion model explained here:

But unfortunately I am unable to find exact same fisheye polynomial (at above page) in any literature. Please direct me towards some literature for more study.

Further, please indicate why the coefficients start with p2 and why not p1. Is p1 intentionally omitted or is there any typing mistake.

Hi Muzq,

The fisheye model is a variation of Scaramuzza’s omnidirectional camera model

Regarding the missing p1 parameter in the model, the p1 parameters is used for normalizing the others. I.e. p1 becomes 1, and the other parameters p2 etc. become normalized by the p1.

Hope it helps :slight_smile: