Depth-of-field reduction due to blurring in a relayed plenoptic camera and mitigation via deconvolution
Depth-of-field reduction due to blurring in a relayed plenoptic camera and mitigation via deconvolution
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DOI：
10.1088/1361-6501/ab614f
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发表时间：
2020-01
影响因子：
2.4
通讯作者：
Z. Tan;B. Thurow
中科院分区：
文献类型：
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作者：
Z. Tan;B. Thurow
经由中继透镜将外部安装的微透镜阵列（MLA）投影到传感器上通常被科学界采用，以代替具有嵌入式传感器上MLA的传统全光相机。在大多数情况下，中继设计更好地支持原型设计和临时设置，而在其他情况下，例如增强的全光成像，由于物理约束，扩展的投影距离是必要的。然而，中继MLA不可避免地使原始图像模糊，通常为1.5 px或更多。我们观察到一个不寻常的行为，其中在原始图像级别的固定模糊产生模糊，这些模糊因重聚焦图像内的深度而恶化-在大多数情况下足以将全光系统的景深减少60%。为了解决这个问题，我们在此提出了一个模型来阐明这种深度相关模糊的机制，并提出了一个Lucy-Richardson反卷积过程来缓解。进行讨论的背景下，定期和加强全光摄影，以及在三维粒子图像测速流体动力学的应用。合成以及实验图像的结果进行了验证。
The projection of an externally-mounted microlens array (MLA) onto a sensor via relay lenses is oft adopted by the scientific community in lieu of traditional plenoptic cameras with embedded on-sensor MLAs. In most cases a relayed design better supports prototyping and temporary setups, while in other cases such as intensified plenoptic imaging the extended projection distance is necessary due to physical constraints. However, relaying the MLA inevitably blurs the raw image, often by 1.5 px or more. We observed an unusual behavior where fixed blurring at the raw image level produced blurs that are worsened by depth within refocused images – enough to reduce the plenoptic system’s depth-of-field by 60% in most cases. To address this problem, we hereby put forth a model to elucidate the mechanism of this depth-dependent blurring, and propose a Lucy–Richardson deconvolution procedure for mitigation. Discussions are undertaken in the contexts of regular and intensified plenoptic photography, as well as application in 3D particle image velocimetry for fluid dynamics. Results were validated on synthetic as well as experimental images.