Camera Calibration Method Based on an Isosceles Right Triangle Planar Pattern

Camera calibration is one of the key steps of 3D reconstruction. Aiming at improving the accuracy and solving the complex problems of camera calibration, based on the camera model, a practical approach of camera calibration based on an isosceles right triangle planar pattern was presented. The camera coordinate system was set as the world coordinate system. Five camera intrinsic parameters needed to be calibrated. The planar pattern contained three apexes of the triangle and two arbitrary points on two right angle sides. More than six pattern images were captured from different poses, the improved Harris detector was used to obtain the sub-pixel coordinates of the corners. Established the constraint equations according to the right angle, camera intrinsic parameters can be calculated. This method reduced the requirements of pattern and was simple and convenient to operate. Experiment shows that the approach is accurate.