Accurate and Fast Field Calibration of Camera with Large FOV

In camera calibration of vision sensor with large FOV(Field Of View),where large calibration jig is usually needed,the camera parameters always vary after calibration and the calibration procedure is time-consuming.To solve the problem,a novel field calibration method is proposed,which is composed of two steps: pre-calibration and field adjustment.Before measuring,the camera is pre-calibrated based on the cross points of a number of rays and a surface precisely,whose orientations and positions are all known.During the process of measuring,position changes of several fixed points on the image are used to adjust the camera.Simulation and practical application show that the relative error is less than 1/10 000 in the measurement range of 8 000 mm×8 000 mm by using the proposed method,which is suitable for field calibration of camera with large FOV.