Generic calibration of cameras with non-parallel optical elements

Multiple cameras are increasingly prevalent for autonomous driving, and the increase need to have 360 degree perception of world space has led to the combination of various cameras in the varieties of narrow-angle and wide-angle field of view. This has led to issues regarding the quality of these optics as a result of bad and cheap designs. Intrinsic calibration is indispensable for accurate perception of the environment in order for it to make accurate decisions such as camera pose estimation and 3-D reconstruction. In this work, we propose a lens distortion model that has been motivated by unintentional tilt in the optical lens system. The proposed distortion model has been added to current state of art generic method of Kannala to form an extended model. To our knowledge, this is the first time that the idea of tilt distortion has been introduced for wide-angle view and fish-eye cameras. We show improved result of 4 to 13% from experiments.