3D shape measurement with 2D area modulated binary patterns

This paper presents a novel area-modulation technique for three-dimensional (3D) shape measurement with binary defocusing. Specifically, this technique modulates local 2×2 pixels to create five grayscale values to enhance fringe quality when the projector is not perfectly in focus. With this novel technique, we will show that the phase error is approximately 1/3 of the square binary method when fringe pattern is dense and the projector is nearly focused.

► Binary defocusing technique for 3D shape measurement. ► Drastically improve measurement quality of the binary defocusing method. ► Significantly enhance the measurement depth range of the binary defocusing method.