Miyazaki Daisuke, Ikeuchi Katsushi
Ikeuchi Laboratory, 3rd Department, Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, Japan 153-8505.
IEEE Trans Pattern Anal Mach Intell. 2007 Nov;29(11):2018-29. doi: 10.1109/TPAMI.2007.1117.
Few methods have been proposed to measure three-dimensional shapes of transparent objects such as those made of glass and acrylic. In this paper, we propose a novel method for estimating the surface shapes of transparent objects by analyzing the polarization state of the light. Existing methods do not fully consider the reflection, refraction, and transmission of the light occurring inside a transparent object. We employ a polarization raytracing method to compute both the path of the light and its polarization state. Polarization raytracing is a combination of conventional raytracing, which calculates the trajectory of light rays, and Mueller calculus, which calculates the polarization state of the light. First, we set an initial value of the shape of the transparent object. Then, by changing the shape, the method minimizes the difference between the input polarization data and the rendered polarization data calculated by polarization raytracing. Finally, after the iterative computation is converged, the shape of the object is obtained. We also evaluate the method by measuring some real transparent objects.
很少有方法被提出来测量诸如玻璃和丙烯酸制成的透明物体的三维形状。在本文中，我们提出了一种通过分析光的偏振态来估计透明物体表面形状的新方法。现有方法没有充分考虑透明物体内部发生的光的反射、折射和透射。我们采用偏振光线追踪方法来计算光的路径及其偏振态。偏振光线追踪是传统光线追踪（计算光线轨迹）和穆勒计算（计算光的偏振态）的结合。首先，我们设置透明物体形状的初始值。然后，通过改变形状，该方法最小化输入偏振数据与通过偏振光线追踪计算出的渲染偏振数据之间的差异。最后，在迭代计算收敛后，获得物体的形状。我们还通过测量一些真实的透明物体来评估该方法。
