1. Introduction
The wide-angle lens has been widely applied in various applications such as computational imaging, virtual reality (VR), and autonomous driving, due to their larger field of view (FoV) than conventional lenses [19], [12], [44], [27]. By employing a specific mapping, the wide-angle lens can produce convex and non-rectilinear images rather than images with straight lines of perspective. However, this mapping mechanism violates the pinhole camera assumption, and the captured image suffers from severe radial distortions.