Sparse 3D reconstruction on a mobile phone with stereo camera for close-range optical tracking

We present a prototype of optical tracking system running on unmodified HTC Evo 3D mobile phone with stereo camera. The system uses checkerboard markers for 3D metric reconstruction of the captured scene. We present the results of camera calibration and we assess the accuracy of tracking, by comparing the 3D point sets obtained from the system with a reference geometry. The accuracy of the prototype turns out to be strongly dependent on the distance from the cameras. The RMS error of 3-dimensional reconstruction of the set of 912 points computed within the distance range of 0.35-1.15 m is 7.4 mm.