Cula Oana G, Dana Kristin J, Pai Dinesh K, Wang Dongsheng
Johnson & Johnson, CPCW, Skillman, NJ 08558, USA.
IEEE Trans Pattern Anal Mach Intell. 2007 Feb;29(2):362-7. doi: 10.1109/TPAMI.2007.39.
Polarization has been used in numerous prior studies for separating diffuse and specular reflectance components, but in this work we show that it also can be used to separate surface reflectance contributions from individual light sources. Our approach is called polarization multiplexing and it has a significant impact in appearance modeling where the image as a function of illumination direction is needed. Multiple unknown light sources can illuminate the scene simultaneously, and the individual contributions to the overall surface reflectance are estimated. Polarization multiplexing relies on the relationship between the light source direction and the intensity modulation. Inverting this transformation enables the individual intensity contributions to be estimated. In addition to polarization multiplexing, we show that phase histograms from the intensity modulations can be used to estimate scene properties including the number of light sources.
在众多先前的研究中，偏振已被用于分离漫反射和镜面反射分量，但在本研究中我们表明，它还可用于分离来自各个光源的表面反射贡献。我们的方法称为偏振复用，它在需要将图像作为照明方向函数的外观建模中具有重大影响。多个未知光源可同时照亮场景，并估计其对整体表面反射的各自贡献。偏振复用依赖于光源方向与强度调制之间的关系。对这种变换进行反演能够估计各个强度贡献。除了偏振复用，我们还表明，强度调制的相位直方图可用于估计包括光源数量在内的场景属性。
