Traditional camera calibration method usually need make complicated 3D calibration block or construct 3D control fields with high precision.In order to avoid this tedious work

we proposed a camera calibration method using planar control grid.First

camera's initial values of intrinsic parameters are determined base on the perfect camera model and its extrinsic parameters using a 2D direct linear transformation and collinearity equations.Image coordinates of planar grid control points are detected using an improved Hough transformation algorithm and least squares fitting.Finally

camera calibration with high accuracy is conducted using bundle adjustment with self-calibration.Good results have been obtained with real image data calibration and demonstrate the method we proposed in this paper is feasible.Calibration precision of principle point and focal length is about 0.2 and 0.3 pixels respectively

which can meet the precision requirements of close-range photogrammetry with high accuracy.