Separation of diffuse and specular components of surface reflection by using Independent Component Analysis

(1)采用高精度数码摄像机和计算机控制的旋转偏光片组成实验观测系统。利用该系统对物体的漫反射和镜面反射分量进行了分离实验。分离效果良好，我们在MIRU2002中发表了这一结果。在这个实验中，我们开发了一种新的分离算法，它利用了任务的特殊性质，比如问题只包含两个组件。该算法直接计算估计的两个分量之间的互信息。由于它是一种枚举算法，所以它是稳定的，我们可以很容易地设置算法参数。(2)为了使我们的方法适用于物体或光线移动的情况，我们制作了一个两幅图像的同时观测系统。在这个系统中，我们使用了半镜棱镜。物体发出的光被棱镜分成两道光线，由两个不同的摄像机观察，摄像机上装有不同偏振方向的偏振器。该观测系统同时给出两幅具有不同数量的镜面和漫射分量的图像。这个系统每秒可以捕捉16对图像。这一结果发表在siio9中。(3)该分离方法发表于IEEE Trans。于2004年4月发布。

(1)We made an experimental observation system with a high-precision digital video camera and a rotating polarizer which is controlled by a computer. By using this system, we made a separation experiment of diffuse and specular reflection components of an object. The separation result was good, and we presented this result in MIRU2002. In this experiment we developed a new separation algorithm which uses a special property of the task, such as the problem includes only two components. The proposed algorithm computes the mutual information between estimated two components directly. Since it is a kind of enumeration algorithm, it is stable and we can set algorithm parameters very easily.(2)We made a simultaneous observation system of two images in order to make our method applicable to cases that objects or lights move. In this system we used a half-mirror prism. The light from the object is split into two rays by the prism, and they are observed by two different video cameras equipped with polarizers of different polarizing directions. This observation system simultaneously gives two images with different amount of specular and diffuse components. This system can capture 16 pairs of images per second. This result was presented in SSIIO9.(3)The proposed separation method appeared in IEEE Trans. on PAMI in April 2004.