Calibration methods for a camera with a tilted lens and a three-dimensional laser scanner in the Scheimpflug condition.

Abstract

A three-dimensional laser scanner has been designed and widely utilized in many fields. The lens plane is tilted according to the Scheimpflug condition and the optical axis is not perpendicular to the charge-coupled device plane. In this case, depth of view can be extended significantly. In this paper, analytical models for a camera with a tilted lens and a laser scanner meeting the Scheimpflug condition are presented. Based on these models, a calibration procedure is detailed. We propose a simple calibration method to determine the intrinsic parameters of a Scheimpflug camera. Meanwhile, two calibration methods for a laser scanner in the Scheimpflug condition are detailed. According to the obtained intrinsic parameters, the laser scanner can be calibrated directly. Moreover, a simple calibration for a three-dimensional laser scanner without the help of a precise positioning system is described. Experimental results show the effectiveness and high measurement accuracy of our calibration methods.