Zhu Jiangping, Zhou Pei, Su Xianyu, You Zhisheng
Opt Express. 2016 Dec 12;24(25):28549-28560. doi: 10.1364/OE.24.028549.
Balancing the accuracy and speed for 3D surface measurement of object is crucial in many important applications. Binary encoding pattern utilizing the high-speed image switching rate of digital mirror device (DMD)-based projector could be used as the candidate for fast even high-speed 3D measurement, but current most schemes only enable the measurement speed, which limit their application scopes. In this paper, we present a binary encoding method and develop an experimental system aiming to solve such a situation. Our approach encodes one computer-generated standard 8 bit sinusoidal fringe pattern into multiple binary patterns (sequence) with designed temporal-spatial binary encoding tactics. The binary pattern sequence is then high-speed and in-focus projected onto the surface of tested object, and then captured by means of temporal-integration imaging to form one sinusoidal fringe image. Further the combination of phase-shifting technique and temporal phase unwrapping algorithm leads to fast and accurate 3D measurement. The systematic accuracy better than 0.08mm is achievable. The measurement results with mask and palm are given to confirm the feasibility.
在许多重要应用中，平衡物体三维表面测量的精度和速度至关重要。利用基于数字微镜器件（DMD）的投影仪的高速图像切换速率的二进制编码图案可作为快速甚至高速三维测量的候选方案，但目前大多数方案仅能实现测量速度，这限制了它们的应用范围。在本文中，我们提出了一种二进制编码方法并开发了一个实验系统，旨在解决这种情况。我们的方法通过设计时空二进制编码策略，将一个计算机生成的标准8位正弦条纹图案编码为多个二进制图案（序列）。然后将二进制图案序列高速且清晰地投影到被测物体表面，接着通过时间积分成像进行采集，以形成一幅正弦条纹图像。进一步结合相移技术和时间相位展开算法，实现了快速且精确的三维测量。系统精度可达优于0.08毫米。给出了对口罩和手掌的测量结果以证实其可行性。
