The phase-coding method for absolute phase measurement possesses a strong robustness because its codewords are encoded into phase domain rather than intensity. However, a misalignment problem arises between fringe order and wrapped phase in this method owing to random noises and image blurring, especially in the high-frequency fringes situation. Therefore, the measurement result is unavailable. To overcome this problem, an optimized phase-coding algorithm is proposed in the study. We use the sinusoidal patterns to generate two opposite binary masks, which can locate half of each codeword. Then, the K-means algorithm is used to correct the codewords errors. The accurate fringe order is obtained by merging two halves of codewords and the absolute phase is recovered afterward. The used method is experimentally verified by an established measurement system, and the results show the proposed method is robustness and efficiency.

用于绝对相位测量的相位编码方法具有很强的鲁棒性，因为其码字被编码到相位域而不是强度中。但是，由于随机噪声和图像模糊，在该方法中条纹阶数和包裹相位之间会出现未对准问题，尤其是在高频条纹情况下。因此，无法获得测量结果。为了克服这个问题，研究中提出了一种优化的相位编码算法。我们使用正弦模式生成两个相对的二进制掩码，它们可以定位每个码字的一半。然后，使用K均值算法来纠正码字错误。通过合并两半码字可以获得准确的条纹顺序，然后恢复绝对相位。