Square wave encoded fringe patterns for high accuracy depth sensing

In this paper, we propose a square wave encoded in three sinusoidal fringe patterns for depth sensing. The periods of the square wave and the sinusoidal wave are coprime. Because of the specific pattern design strategy, a Gabor filter is used to obtain the wrapped phase, and the coprime theorem is utilized to reliably determine the absolute phase of the encoded sinusoidal wave. Quantitative analyses and practical experiments have been presented to verify the performance of the proposed method. The precision of our method is close to that of the classic three-step phase-shifting method. Besides, depth of discontinuous surfaces can be correctly measured. By adopting a high-resolution projector and camera, our proposed method can acquire a denser and more precise depth map than an original Kinect and ToF camera.