Two-Dimensional Non-Line-of-Sight Scene Estimation From a Single Edge Occluder
Two-Dimensional Non-Line-of-Sight Scene Estimation From a Single Edge Occluder
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DOI：
10.1109/tci.2020.3037405
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发表时间：
2021-01-01
影响因子：
5.4
通讯作者：
Goyal, Vivek K.
中科院分区：
文献类型：
--
作者：
Seidel, Sheila W.;Murray-Bruce, John;Goyal, Vivek K.
无源非视线成像方法通常比有源成像方法更快、更隐蔽，需要的设备也更简单、更便宜。然而，这些方法中的许多都利用遮挡物或隐藏场景的运动，或者需要复杂遮挡物的知识或校准。墙的边缘是一种已知的普遍存在的遮挡结构，可以用作光圈来成像隐藏在它后面的区域。来自拐角周围的光投射到地板上，形成扇形半影而不是锐利的阴影。半影的细微变化包含了大量关于隐藏场景的信息。以前的工作已经利用边缘的垂直性质来演示1D（在拐角处测量的角度）重建移动和静止的隐藏场景，只要一张半影的照片。在这项工作中，我们引入了第二个重建维度：从边缘测量的范围。我们推导出一个新的正演模型，占径向衰减，并提出了两个反演算法，形成一个单一的半影照片的二维重建。这两种算法的性能表现在对应于几个不同的隐藏场景配置的实验数据。Cramer-Rao界限分析进一步证明了2D角相机的可行性（和实用性）。
Passive non-line-of-sight imaging methods are often faster and stealthier than their active counterparts, requiring less complex and costly equipment. However, many of these methods exploit motion of an occluder or the hidden scene, or require knowledge or calibration of complicated occluders. The edge of a wall is a known and ubiquitous occluding structure that may be used as an aperture to image the region hidden behind it. Light from around the corner is cast onto the floor forming a fan-like penumbra rather than a sharp shadow. Subtle variations in the penumbra contain a remarkable amount of information about the hidden scene. Previous work has leveraged the vertical nature of the edge to demonstrate 1D (in angle measured around the corner) reconstructions of moving and stationary hidden scenery from as little as a single photograph of the penumbra. In this work, we introduce a second reconstruction dimension: range measured from the edge. We derive a new forward model, accounting for radial falloff, and propose two inversion algorithms to form 2D reconstructions from a single photograph of the penumbra. Performances of both algorithms are demonstrated on experimental data corresponding to several different hidden scene configurations. A Cramer-Rao bound analysis further demonstrates the feasibility (and utility) of the 2D corner camera.