We tackle an optical measurement of the internal structure of a diffuse surface object—we define as an object that has a diffuse surface and its interior is transparent, like grapes or hollow plastic bottles. Our approach is based on optical tomography that reconstructs the interior from observations of absorption of light rays from various views, under the projection of the light. The difficulty lies in the fact that a light ray that enters changes its direction at the interaction of the surface, unlike X-ray that travels straight through the object. We introduce a model of light path in the object called shortest-path model. We acquire the absorption of light rays through the object by the measurement upon the assumption of the model. Since this measurement acquires insufficient observation to reconstruct the interior by conventional reconstruction algorithms, we also introduce a reconstruction method based on a numerical optimization that a physical requirement of the absorption is taken into account. Our method is confirmed successful to measure the interior in a real-world experiment.

中文翻译：

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基于最短路径模型的漫射表面物体光学层析成像

我们对散射表面对象的内部结构进行光学测量-我们将其定义为具有散射表面并且其内部是透明的对象，例如葡萄或中空的塑料瓶。我们的方法基于光学层析成像技术，该技术根据光线投射下各种角度的光线吸收观察来重建内部。困难在于，与直接穿过物体的X射线不同，进入的光线在表面的交互作用下会改变其方向。我们在对象中引入了光路模型，称为最短路径模型。我们在模型假设的基础上通过测量获得通过物体的光线吸收。由于此测量无法通过常规重建算法获得足够的观测值来重建内部，因此我们还基于数值优化引入了一种重建方法，该方法考虑了吸收的物理要求。我们的方法在实际实验中被证实可以成功地测量室内。