Calibration of a foveated wide-angle lens on an active vision head

Abstract

Inspired by the properties of the human visual system, a new active vision system called ESCHeR (Etl Stereo Compact Head For Robot Vision) has been recently implemented with foveated wide angle lenses. The lenses exhibit a wide field of view along with a space-varying resolution for facilitating both detection and close observation. However, to handle such optical properties and achieve basic eye movement functions, new calibration methods are needed. Therefore, two novel and online techniques are presented that in one case perform a global identification of the optical process through artificial neural techniques and in the other case compute the physical parameters by using environmental feature-tracking and controlled rotations of the cameras. Self-alignment of the cameras is also achieved using a similar technique.