Camera calibration and Euclidean reconstruction from known observer translations

We present a technique for camera calibration and Euclidean reconstruction from multiple images of the same scene. Unlike standard Tsai´s camera calibration from a known scene, we exploited controlled known motions of the camera to obtain its calibration and Euclidean reconstruction without any knowledge about the scene. We consider three linearly independent translations of an uncalibrated camera mounted on a robot arm that provides us with four views of the scene. The translations of the robot arm are measured in a robot coordinate system. This special, but still realistic, arrangement allowed us to find a linear algorithm for recovering all intrinsic camera calibration parameters, the rotation of the camera with respect to the robot coordinate system, and proper scaling factors for all points allowing their Euclidean reconstruction. The experiments showed that an efficient and robust algorithm was obtained by exploiting Total Least Squares in combination with careful normalization of image coordinates.