Single-Shot Reflectance Measurement from Polarized Color Gradient Illumination
Single-Shot Reflectance Measurement from Polarized Color Gradient Illumination
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偏振颜色梯度照明的单次反射率测量
DOI：
10.1109/iccphot.2015.7168375
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
P. Debevec
中科院分区：
文献类型：
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作者：
Graham Fyffe;P. Debevec
我们提出了一种在单个时刻获取对象的每像素漫反射反照率、镜面反照率和表面法线贴图的方法。该方法是单次拍摄的，不需要光流，并且是按像素进行的，不会对反照率统计数据或表面连通性做出任何假设。我们在球面照明设备内拍摄对象，该设备发射垂直偏振的RGB颜色梯度与XYZ轴对齐的静态照明图案，以及水平偏振的RGB颜色梯度与XYZ轴相反对齐的图案。我们使用两种可能的设置之一来捕捉同时拍摄的照片：一种是使用带有偏振分束器的同轴对准相机的单视图设置，另一种是在相机上放置不同方向的线性偏振滤光片的多视立体设置，从而实现高质量的几何重建。从这种照明中，我们得到了适合于介质材料的全色漫反射反照率、单通道镜面反照率，以及不受次表面散射破坏的偏振保持表面法线。我们提供了简单的公式来估计单视和多视情况下的漫射反照率、镜面反照率和表面法向图，并给出了包括人脸在内的许多常见对象的误差界。
We present a method for acquiring the per-pixel diffuse albedo, specular albedo, and surface normal maps of a subject at a single instant in time. The method is single-shot, requiring no optical flow, and per-pixel, making no assumptions regarding albedo statistics or surface connectivity. We photograph the subject inside a spherical illumination device emitting a static lighting pattern of vertically polarized RGB color gradients aligned with the XYZ axes, and horizontally polarized RGB color gradients inversely aligned with the XYZ axes. We capture simultaneous photographs using one of two possible setups: a single-view setup using a coaxially aligned camera pair with a polarizing beam splitter, and a multi-view stereo setup with different orientations of linear polarizing filters placed on the cameras, enabling high-quality geometry reconstruction. From this lighting we derive full-color diffuse albedo, single-channel specular albedo suitable for dielectric materials, and polarization-preserving surface normals which are free of corruption from subsurface scattering. We provide simple formulae to estimate the diffuse albedo, specular albedo, and surface normal maps in the single-view and multi-view cases and show error bounds which are smallfor many common subjects including faces.