Fringe projection profilometry has been increasingly sought and applied in dynamic three-dimensional (3D) shape measurement. In this work, a robust and high-efficiency 3D measurement based on Gray-code light is proposed. Unlike the traditional method, a novel tripartite phase unwrapping method is proposed to avoid the jump errors on the boundary of code words, which are mainly caused by the defocusing of the projector and the motion of the tested object. Subsequently, the time-overlapping coding strategy is presented to greatly increase the coding efficiency, decreasing the projected number in each group, e.g. from 7 (3 + 4) to 4 (3 + 1) for one restored 3D frame. Combination of two proposed techniques allows to reconstruct a pixel-wise and unambiguous 3D geometry of dynamic scenes with strong noise using every 4 projected patterns. The presented techniques preserve the high anti-noise ability of Gray-coded-based method while overcoming the drawbacks of jump errors and low coding efficiency. Experiments have demonstrated that the proposed method can achieve the robust and high-efficiency 3D shape measurement of high-speed dynamic scenes even polluted by strong noise.

中文翻译：

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基于格雷码光的高速高效三维形状测量

在动态三维 (3D) 形状测量中越来越多地寻求和应用条纹投影轮廓测量法。在这项工作中，提出了一种基于格雷码光的稳健高效的 3D 测量。与传统方法不同，提出了一种新的三方相位解缠方法来避免码字边界上的跳跃错误，这些错误主要是由投影仪的散焦和被测物体的运动引起的。随后，提出了时间重叠编码策略以大大提高编码效率，减少每组中的投影数，例如，对于一个恢复的 3D 帧，从 7 (3 + 4) 到 4 (3 + 1)。两种提议技术的组合允许使用每 4 个投影模式重建具有强噪声的动态场景的像素级和明确 3D 几何。所提出的技术保留了基于格雷编码的方法的高抗噪能力，同时克服了跳跃错误和低编码效率的缺点。实验表明，所提出的方法即使被强噪声污染，也可以实现对高速动态场景的鲁棒和高效的3D形状测量。