Novel adaptive fringe projection technique for high dynamic range 3D shape measurement

Fringe Projection Profilometry (FPP) is a popular optical method for 3D shape measurement because of its high accuracy, fast measurement speed and full-field inspection nature. However, due to the limited dynamic range of the digital camera, saturated and dark pixels in the captured images will lead to serious phase error and measurement error when the measured object has a drastic texture variation. To deal with such problem, a novel adaptive digital fringe projection technique for high dynamic 3D shape measurement is proposed. In this method, phase-shifting fringes are adaptively generated with the aid of a coordinates mapping process and binary-search technique. Compared with previous adaptive fringe projection techniques, the camera response function and homographic mapping between the camera and projector are not needed, making the whole measurement easier to carry out and less laborious. Experiments validate the effectiveness and superiority of the proposed method for high dynamic range 3D shape measurement.