CONSTRAINING OBJECT FEATURES USING A POLARIZATION REFLECTANCE MODEL
CONSTRAINING OBJECT FEATURES USING A POLARIZATION REFLECTANCE MODEL
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DOI：
10.1109/34.85655
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发表时间：
1991-07-01
影响因子：
23.6
通讯作者：
BOULT, TE
中科院分区：
文献类型：
--
作者：
WOLFF, LB;BOULT, TE
计算机视觉的一个增长趋势是使用物理反射率模型，预测反射的辐射强度和颜色，以获得对物体特征的约束。 直到最近，人们对光的反射偏振态的分析以及这可能为自动视觉系统提供哪些特征限制的关注相对较少。 尽管与人类视觉没有类比，但我们证明，通过使用放置在相机传感器前面的偏振滤光片解析反射光的偏振分量，可以获得大量的约束信息。 我们提出了一种称为菲涅耳反射模型的偏振反射模型，因为它使用菲涅耳反射系数。 该反射率模型准确地预测了反射光的偏振分量的大小，并且本文中提出的所有基于偏振的方法都遵循该模型。我们展示了基于偏振的方法根据不同的相对电导率水平来分割材料表面的能力，特别是区分不导电的电介质和高导电性的金属。 基于偏振的方法可以提供线索来区分由固有明暗或颜色变化引起的不同强度边缘类型、由镜面反射引起的强度边缘以及由观看方向几乎与表面法线正交的遮挡轮廓引起的强度边缘。 对反射偏振分量的分析还表明，可以分离反射的漫反射分量和镜面反射分量，从而清晰地显示被镜面眩光饱和的内在表面细节。 最后，我们讨论用于约束表面法线的基于偏振的方法。
A growing trend in computer vision has been the use of physical reflectance models, predicting reflected radiant intensity and color, to obtain constraints on object features. Until recently, relatively little attention has been paid to analysis of the reflected polarization state of light and what feature constraints this might provide to an automated vision system. Even though there is no analogy with human vision, we demonstrate that a wealth of constraint information can be obtained by resolving polarization components of reflected light with a polarizing filter placed in front of a camera sensor. We present a polarization reflectance model known as the Fresnel reflectance model because of its use of the Fresnel reflection coefficients. This reflectance model accurately predicts the magnitudes of polarization components of reflected light, and all the polarization-based methods presented in this paper follow from this model.We demonstrate the capability of polarization-based methods to segment material surfaces according to varying levels of relative electrical conductivity, in particular distinguishing dielectrics, which are nonconducting, and metals, which are highly conductive. Polarization-based methods can provide cues for distinguishing different intensity-edge types arising from intrinsic light-dark or color variations, intensity edges caused by specularities, and intensity edges caused by occluding contours where the viewing direction becomes nearly orthogonal to surface normals. Analysis of reflected polarization components is also shown to enable the separation of diffuse and specular components of reflection, unobscuring intrinsic surface detail saturated by specular glare. Finally, we address polarization-based methods used for constraining surface normals.