Ternary Gray code-based phase unwrapping for 3D measurement using binary patterns with projector defocusing

The three-dimensional measurement technique using binary pattern projection with projector defocusing has become increasingly important due to its high speed and high accuracy. To obtain even faster speed without sacrificing accuracy, a ternary Gray code-based phase-unwrapping method is proposed by using even fewer binary patterns, which makes it possible to efficiently and accurately unwrap the phase. Theoretical analysis, simulations, and experiments are presented to validate the proposed method's efficiency and robustness.