Large depth-of-field microscopic structured-light 3D imaging with focus stacking
Large depth-of-field microscopic structured-light 3D imaging with focus stacking
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DOI：
10.1016/j.optlaseng.2023.107623
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发表时间：
2023
影响因子：
4.6
通讯作者：
Liming Chen;Song Zhang
中科院分区：
文献类型：
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作者：
Liming Chen;Song Zhang
最先进的显微结构光 (SL) 三维 (3D) 成像系统通常使用具有固定焦距的传统镜头，可实现有限的景深 (DOF)。本文提出通过利用焦点堆叠技术和开发一种新颖的计算框架来大幅增加显微 3D 成像的自由度。我们首先使用电可调镜头（ETL）捕获具有不同相机焦距的条纹图像，并使用相位约束对齐恢复的相位图。然后，我们使用条纹对比度提取聚焦像素相位，并通过能量最小化将它们拼接成全焦点相位图。最后，我们使用全焦点相位图重建 3D 形状。实验结果表明，我们提出的方法可以实现约 2 mm 的大 DOF 和约 4 mm × 3 mm 的视场 (FOV)，物体空间的像素尺寸约为 2.6 μm。所获得的 DOF 约为未采用所提出方法的系统 DOF 的 10 × 。
State-of-the-art microscopic structured-light (SL) three-dimensional (3D) imaging systems typically use conventional lenses with a fixed focal length achieving a limited depth of field (DOF). This paper proposes to drastically increase the DOF of the microscopic 3D imaging by leveraging the focus stacking technique and developing a novel computational framework. We first capture fringe images with various camera focal lengths using an electrically tunable lens (ETL) and align the recovered phase maps using phase constraints. Then, we extract the focused pixel phase using fringe contrast and stitch them into an all-in-focus phase map via energy minimization. Finally, we reconstruct the 3D shape using the all-in-focus phase map. Experimental results demonstrate that our proposed method can achieve a large DOF of approximately 2 mm and field of view (FOV) of approximately 4 mm × 3 mm with a pixel size at the object space of approximately 2.6 μm. The achieved DOF is approximately 10 × the DOF of the system without the proposed method.