Intensity-optimized dithering technique for three-dimensional shape measurement with projector defocusing

•Novel findings on dithering technique optimization: the optimization should be performed in the intensity domain rather than in the phase domain.•Significantly and consistently enhanced the measurement quality of the binary defocusing when the projector is nearly focused.•Could drastically enhance the capability of the binary defocusing technique.

Our previously proposed phase-based optimization method [1] has proven successful in improving the measurement quality when a dithering technique is used. This paper presents an intensity-based optimization method for 3D shape measurement with binary dithering techniques. Both simulations and experiments find that the phase-based optimization method can generate high-quality phase under a given condition, but it is sensitive to the amount of defocusing. In contrast, the proposed intensity-based optimization method can consistently generate high-quality phase with various amounts of defocusing.