Calibrating a Fish-eye camera / webcam with large angle mounted on car by using opencv 3
One important issue is to define the calibration pattern and its position !!!!
The affects error that paly an essential role in the camera calibration process; of either localizing the control point or using geometric properties of the pattern directly. Therefore, the precise localization of control points, or accurate determination of the geometric properties is very important, when a small error lead to imprecise camera calibration .Therefore I decided to use a regular grid of circles as calibration pattern. But when using the wide angle lens the camera location has a big inclination with respect to the calibration pattern. Therefore, the size of the control points circles varies a lot (circle radius of the most remote circles could be smaller than those close to the lens).
According to that how can determine rows=? X columns=? of the calibration sheet, and the distance = ? between each row an column, and the position=? for the calibration sheet, in order to obtain the accurate calibration for the camera mounted on the car .