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

(1)We利用高精度数字摄像机和计算机控制的旋转偏光镜，制作了一套实验观测系统。利用该系统进行了物体漫反射和镜面反射分量的分离实验。分离效果良好，并在MIRU 2002上发表。在这个实验中，我们开发了一个新的分离算法，它使用了任务的一个特殊属性，例如问题只包括两个组件。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，并且我们可以很容易地设置算法参数。(2)We为了使我们的方法适用于物体或光运动的情况，我们制作了一个同时观察两个图像的系统。在这个系统中，我们使用了半反射镜棱镜。来自物体的光被棱镜分成两条光线，它们被两台装有不同偏振方向的偏振器的不同摄像机观察。该观察系统同时给出具有不同数量的镜面反射和漫射分量的两个图像。该系统每秒可捕获16对图像。该结果在SSIO9中给出。（3）提出的分离方法于2004年4月发表在IEEE Trans.on PAMI上。

(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.