Zhu Ronggang, Li Bo, Zhu Rihong, He Yong, Li Jianxin
Appl Opt. 2017 Mar 20;56(9):2556-2562. doi: 10.1364/AO.56.002556.
An advanced carrier squeezing interferometry (CSI) technique is proposed to suppress gamma distortion in fringe projection profilometry. CSI combines phase-shifted fringes into a single spatial-temporal fringe and then extracts the phase from its frequency spectrum. Although it has the property of rejecting high-order harmonics, the traditional CSI technique uses an approximate model that generates extra disturbance lobes in the process of phase extraction from the frequency domain. Therefore, the filter window used to extract the phase has to be very narrow, which results in the extra loss of high-frequency information. In this paper, we improve the approximate model by introducing a phase-correction term and encoding it into the projected standard fringes. Then, there are no extra disturbance lobes in the spectrum, and the acceptable filter window to reject high-order harmonics can be much wider. Thus, it is possible to preserve more high-frequency information in the retrieved phase. We performed simulations and experiments to validate the ability of this method to suppress gamma distortion and preserve high-frequency information as compared to the traditional CSI method.
提出了一种先进的载波压缩干涉测量（CSI）技术来抑制条纹投影轮廓术中的伽马失真。CSI将相移条纹组合成单个时空条纹，然后从其频谱中提取相位。尽管它具有抑制高阶谐波的特性，但传统的CSI技术使用的是近似模型，该模型在从频域提取相位的过程中会产生额外的干扰瓣。因此，用于提取相位的滤波窗口必须非常窄，这导致高频信息的额外损失。在本文中，我们通过引入相位校正项并将其编码到投影的标准条纹中来改进近似模型。然后，频谱中不会有额外的干扰瓣，并且用于抑制高阶谐波的可接受滤波窗口可以宽得多。因此，有可能在恢复的相位中保留更多的高频信息。我们进行了模拟和实验，以验证该方法与传统CSI方法相比抑制伽马失真和保留高频信息的能力。
